Something I learned last weekend, about temp

[Quiettime]

I'm using a Lee Pro 420 (220v, heats up really quick, glad I went that way) and Lee molds at this time, and a Lyman thermometer. @800 on the therm, just wasn't getting good pours, lots of wrinkles, bad fillout, even with preheating molds and being very careful.

No signs of frosting, so I just started cranking the temp up. Therm is reading over 1000 deg and the lead starts really flowing well. It is now a fine stream instead of like pouring syrup. Mold fillout gets really good, real square consistent driving bands and still no frosting.

Obviously my thermometer is off by a couple hundred degrees at least. And I bought the Lyman because it was more expensive than Lee so it should be better, right? :veryconfu

But it was like a whole new level when those molds started filling out like that. Like a light came on.

Who makes a good, accurate thermometer?

[engineer401]

I bought the RCBS because the customer comments regarding Lyman were not complimentary. I mnever calibrated the thermometer but it reads 700 degrees with good fill out.

[Tatume]

Sounds like you need to turn it up a little more. Is it cold outside where you live? That may be keeping your mold too cool to produce good, frosted bullets. It they're filled out like you say, then they are probably good enough, but a little frosting tells the story of a good bullet.

[Quiettime]

Not real cold down here in FLA, just really humid!

I would just continue to use the Lyman but it stops at 1000 so I'm guessing past that...

[OuchHot!]

I have had two dial thermometers over the last few decades and one was as bad as yours and the other was off about 75F around melting temps.....I went to thermocouples and digital readouts. I do other things that require very fine temp. management so I justified expensive equipment. Nowadays I have found new stuff that is cheap to be amazingly accurate in the 500-800F range. Even many multimeters (volts, ohms, amps) often have a j-thermocouple input.

[geargnasher]

Consider the possibility that the thermometer could be correct and you have still to learn the lesson about the importance of adequate MOULD temperature.....and find how to achieve it without pouring thousand-degree alloy.

Gear

[Quiettime]

Gear: I have considered that, being a relative noob, but would not the boolits be frosty at over 1000*? And, the pour just seemed to magically get way easier, like pouring syrup straight out of the microwave rather than straight from the cabinet. It just seemed like "hey, this is how it is supposed to work".

OuchHot: tell me more about this "new stuff that is cheap" of which you speak!

[Cherokee]

I have a Lyman thermometer, used it for years with Lee pot and it seemed good. When I bought an RCBS pot and used the thermometer, it showed 450* when the pot was set at 750*. Don't use the Lyman any more. Funny thing is, both pots yield great boolits.

[MT Gianni]

A thermometer is a standard. If your shows water boils @ 300 F it isn't accurate. That doesn't keep you from noting you get your best bullets when it reads XXX and taking your melt to that point. Accuracy isn't really needed for most boolit making just repeatability. Pure lead melts @ 621.5 F so get some pure and see what it does with your t/stat. make sure it is pure but those are your reference points.

[geargnasher]

Gear: I have considered that, being a relative noob, but would not the boolits be frosty at over 1000*? And, the pour just seemed to magically get way easier, like pouring syrup straight out of the microwave rather than straight from the cabinet. It just seemed like "hey, this is how it is supposed to work".

OuchHot: tell me more about this "new stuff that is cheap" of which you speak!

"Frosting" is an effect caused by two things in combination: The presence of antimony in the mix, and a very hot mould.

The temperature of the metal going into the mould has zero to do with whether or not the boolit surfaces will have the "frosted" appearance, that is 100% a function of mould block temperature and cooling rate, or rather the SLOW cooling rate, of the alloy. The more slowly an antimonial alloy cools, the more time the antimony dendrite crystals have to form lattices, and the appearance of a textured surface becomes present.

For example, I can literally pour 800-degree wheel-weight metal into a 200-degree mould and get shiny, wrinkled boolits with rounded edges. I can also pour 650-degree wheel weight metal into a 450-degree mould and make boolits that are so frosted and undersized that they appear as rough and dull as freshly-broken cast iron, or appear as if they were sand blasted. The difference is the temperature of the MOULD, not the alloy. And, of course, the presence of some antimony in the mix. Tin/lead alloy or pure lead always casts fairly shiny, regardless of mould temperature or alloy temperature.

The general rule for most of the ternary (lead, antimony, tin) alloys that we scrounge up for making boolits is to run the pot below 750 degrees F., or really about 100-150 degrees hotter than the fully-liquid point, and to preheat the moulds somehow (dip a corner in the melt for a while, set across top of pot for a few minutes, or improvise a "mould oven" using a hot plate and metal box) so they come up to casting temperature faster or start out at casting temperature. THEN, as you cast, maintain a pace that is brisk enough to keep the mould hot enough for good fillout.

Casting good boolits is all about consistency. Constant pot temperature is important, this is what your thermostat and thermometer are for. Constant mould temperature is even more important, and that is controlled simply by adjusting the timing of the various pouring, waiting for sprue to set, cutting, opening, dumping, closing, and refilling operations. Casting boolits is like driving a car on the highway, you have to constantly make slight corrections to steering, throttle, brake, etc. and watch your mirrors, the road, anticipate hills and valleys to keep the speed consistent and in the "zone" that you want to be.

You'll have to experiment with timing operations and pouring stream adjustment, technique, sprue puddle size, etc. while watching for frosting, rounded edges, filled bases, air bubbles/voids in the bases, wrinkles, shiny spots, frosted bands/shiny noses, sprue flashover time to give yourself clues about what is working and not working with a particular mould, alloy, and atmospheric condition.



Here's a quick and dirty method that works every time. Turn on the pot and start melting your alloy. Stir it with a spoon as soon as it starts to get mushy and watch the thermometer. Once the metal thins out like thin porridge, keep a close eye on temperature, it should remain constant as the phase changes. Once the last bits of grainy metal go away, the temperature should start to rise again (the metal is past the phase platau). Record the phase plateau temperature and add, say, 150F to it. Allow the alloy to reach this temperature and adjust the pot to maintain it. Spoon in a layer of pine sawdust on top of the melt and stir the alloy gently to flux and reduce oxides. Skim if you want, or not. Dip a corner of your mould down int he metal and hold it there until the alloy no longer sticks to the blocks when you withdraw it, this could take anywhere from 30 seconds to two minutes. Dip the tip of the sprue plate in the alloy too, for about ten seconds, then close the mould and start casting. The mould should suck the pot temperature down 50 or so degrees depending on the size of the mould. Fill, cut, and dump the first few castings quickly and glance at the boolits. If shiny and wrinkled, keep casting culls as fast as you can until they start to fill out and get an even, satin frost all over. From this point on, you can play with the timing and sprue puddle size to control mould block and sprue plate temperature to keep the mould temperature and boolit quality even from nose to tip.

This works with any alloy, any pot, any pouring technique, and any mould (except non-antimony alloys won't frost, you just look for sharp edges and good fillout with those) and any weather. Don't forget to glance at the pot temperature once in a while and make sure it stays 100-150 above the fully-liquid point that you recorded first thing. It's all up to mould temperature and technique after that, and trust me, quit dinking around with pot temperature, it is not going to do you any good.

One more thing, to emphasize what MT Gianni wrote, IF your thermometer is off even 200 degrees, if you do as I described above, it won't matter because you only want to obtain an alloy temperature that is a certain amount above fully liquidus with ANY alloy, and your thermometer is good enough to give you that valuable reference point even if it is not giving you an exactly accurate temperature reading.

Gear

[BNE]

This is why this sight is of such value. Good stuff Gear.

[jeepyj]

Gear, I'm not sure what others extracted from your post but I would like say I was very nicely written. I've been casting a long time with great success and I picked a ton of good useful information from your post.
Thank you, Jeepyj

[William Yanda]

Thanks Gear. Succinct and well stated.
I've used single round ball molds, Al and brass, even a Lee 1 Oz. slug mold with no difficulties. Recently branched out to a 2 holer in .44, 250 gr. and experienced wrinkled boolets. Actually better success with a 6 banger casting 200 grain boolets.
Mold temperature is critical.

[Land Owner]

Can we get a "Sticky" on that post gear? "Frosting - more than just sugar!" (hehe).

I have been a member for ~2 years, and in that time I have not read a more thorough description.

[Mal Paso]

Sticky! This is just one of many fine posts by Gear. It would be nice if they were all in one place.

[Dennis Eugene]

Long posts often turn me off, but after reading all the at a boys I went back and read Gears post, glad I did. Dennis

[leadman]

Since the OP thermometer is reading over 1000 degrees and hard to take a reading as there are no numbers past 1000 it might help to adjust it so it reads within the scale on the face.
My older Lyman thermometer was off also so I gently grabbed the probe and turned the head and set it this way. The head turns on the probe to adjust the needle.
And Gears post was a very good one.

[doctorggg]

Gear,

A tremendous post from which i learned a lot. Thank you for taking the time to write it. i am sure it will help a lot of members.
Be blessed.

[geargnasher]

I struggled for 15 years and many buckets of wheel weights before finding this site, some well-written books on the subject that I didn't know existed before, and was finally able to sort fact from myth for myself. It is a hundred times more difficult to figure this out if you have to sort the misinformation from simple fact as opposed to simply getting the facts in the first place. I see people getting fed the wrong information constantly and know where that road will lead: Frustration and probably giving up the hobby because there is too much "witchcraft" involved with it. My aim is to distill the facts as I see them and stop the wive's tales that pervade this hobby to the detriment of newcomers. I wish someone had done that for me 20 years ago, I'd be a lot further along by now.

BTW, most of what I explained above is outlined in The Lyman Cast Bullet Handbook, third edition, but the style is more academic than technical and somewhat difficult to distill if you don't already have a general idea of the factors involved with casting metal.

As for long posts, I don't really like them either, but if one can only condense information/instructions to a certain point before it loses value.

Gear

[willvabch]

Gear,
Great job, I liked the article.

[montana_charlie]

I see people getting fed the wrong information constantly and know where that road will lead: Frustration and probably giving up the hobby because there is too much "witchcraft" involved with it.
But, you have to hang around here for years, and slowly build up a reputation for knowing something, before you can state that simple truth and not have the 'experts' blowing fuses in unison.

A person may 'learn the truth' soon after arriving or may know it when he shows up.
But if he tells what he knows to soon, he won't be believed when all of the 'frosters' weigh in.

CM

[smokeywolf]

Very nice write-up gear. Sometimes it's not just the information by itself, but how it's presented. You presented the info in such a way as to cause me to actually form a mental picture, a movie in my mind, of me standing at my casting bench performing each action that you described.

Your literacy is showing through.

smokeywolf

[Polecat]

Gear you cain't have all that information in one head you have got to have two. LOL

[Quiettime]

Since the OP thermometer is reading over 1000 degrees and hard to take a reading as there are no numbers past 1000 it might help to adjust it so it reads within the scale ........ head turns on the probe to adjust the needle. .

For some reason I didn't think you could do that. I have a habit of breaking things...will try, but I think I'm also going to get another thermometer to double check.

[41 mag fan]

Gear,
That was so useful i copied it and emailed it to myself for future reference...thank you for your meaningful and informational posts

[MT Gianni]

The post is now stickied? Stuck? pinned up top.

[Quiettime]

"Frosting" is an effect caused by two things in combination: The presence of antimony in the mix, and a very hot mould.

The temperature of the metal going into the mould has zero to do with whether or not the boolit surfaces will have the "frosted" appearance, that is 100% a function of mould block temperature and cooling rate, or rather the SLOW cooling rate, of the alloy. The more slowly an antimonial alloy cools, the more time the antimony dendrite crystals have to form lattices, and the appearance of a textured surface becomes present.

For example, I can literally pour 800-degree wheel-weight metal into a 200-degree mould and get shiny, wrinkled boolits with rounded edges. I can also pour 650-degree wheel weight metal into a 450-degree mould and make boolits that are so frosted and undersized that they appear as rough and dull as freshly-broken cast iron, or appear as if they were sand blasted. The difference is the temperature of the MOULD, not the alloy. And, of course, the presence of some antimony in the mix. Tin/lead alloy or pure lead always casts fairly shiny, regardless of mould temperature or alloy temperature.

The general rule for most of the ternary (lead, antimony, tin) alloys that we scrounge up for making boolits is to run the pot below 750 degrees F., or really about 100-150 degrees hotter than the fully-liquid point, and to preheat the moulds somehow (dip a corner in the melt for a while, set across top of pot for a few minutes, or improvise a "mould oven" using a hot plate and metal box) so they come up to casting temperature faster or start out at casting temperature. THEN, as you cast, maintain a pace that is brisk enough to keep the mould hot enough for good fillout.

Casting good boolits is all about consistency. Constant pot temperature is important, this is what your thermostat and thermometer are for. Constant mould temperature is even more important, and that is controlled simply by adjusting the timing of the various pouring, waiting for sprue to set, cutting, opening, dumping, closing, and refilling operations. Casting boolits is like driving a car on the highway, you have to constantly make slight corrections to steering, throttle, brake, etc. and watch your mirrors, the road, anticipate hills and valleys to keep the speed consistent and in the "zone" that you want to be.

You'll have to experiment with timing operations and pouring stream adjustment, technique, sprue puddle size, etc. while watching for frosting, rounded edges, filled bases, air bubbles/voids in the bases, wrinkles, shiny spots, frosted bands/shiny noses, sprue flashover time to give yourself clues about what is working and not working with a particular mould, alloy, and atmospheric condition.



Here's a quick and dirty method that works every time. Turn on the pot and start melting your alloy. Stir it with a spoon as soon as it starts to get mushy and watch the thermometer. Once the metal thins out like thin porridge, keep a close eye on temperature, it should remain constant as the phase changes. Once the last bits of grainy metal go away, the temperature should start to rise again (the metal is past the phase platau). Record the phase plateau temperature and add, say, 150F to it. Allow the alloy to reach this temperature and adjust the pot to maintain it. Spoon in a layer of pine sawdust on top of the melt and stir the alloy gently to flux and reduce oxides. Skim if you want, or not. Dip a corner of your mould down int he metal and hold it there until the alloy no longer sticks to the blocks when you withdraw it, this could take anywhere from 30 seconds to two minutes. Dip the tip of the sprue plate in the alloy too, for about ten seconds, then close the mould and start casting. The mould should suck the pot temperature down 50 or so degrees depending on the size of the mould. Fill, cut, and dump the first few castings quickly and glance at the boolits. If shiny and wrinkled, keep casting culls as fast as you can until they start to fill out and get an even, satin frost all over. From this point on, you can play with the timing and sprue puddle size to control mould block and sprue plate temperature to keep the mould temperature and boolit quality even from nose to tip.

This works with any alloy, any pot, any pouring technique, and any mould (except non-antimony alloys won't frost, you just look for sharp edges and good fillout with those) and any weather. Don't forget to glance at the pot temperature once in a while and make sure it stays 100-150 above the fully-liquid point that you recorded first thing. It's all up to mould temperature and technique after that, and trust me, quit dinking around with pot temperature, it is not going to do you any good.

One more thing, to emphasize what MT Gianni wrote, IF your thermometer is off even 200 degrees, if you do as I described above, it won't matter because you only want to obtain an alloy temperature that is a certain amount above fully liquidus with ANY alloy, and your thermometer is good enough to give you that valuable reference point even if it is not giving you an exactly accurate temperature reading.

Gear

Wilco

[Slow Elk 45/70]

YUP, this is a lot of good info in one place, well presented..... if a feller can't read the info and understand what is being said , ......well he may need to read it again, Good job Gear

[cbrick]

As for the thermometers it doesn't surprise me in the least that the OP's reads 1000 degrees even though it's doubtful the alloy was that hot. I had a heck of time back before PID's trying to get an accurate thermometer. I placed three of them in the same pot at the same time and couldn't tell within 100 degrees what the melt temp was and couldn't tell within 100 degrees what the alloy temp was when casting. This was my original reason for getting a PID controlled pot.

Most if not all American made lead thermometers are made by Tru-Tel regardless if it says RCBS or Lyman or whatever. None of the lead thermometers I've had were particularly accurate though most were reasonably repeatable.

Rick

[geargnasher]

Here are some excerpts from another thread a while ago addressing this same alloy/mould temperature thing, and I wanted to include it here because some things like the behavior of tin above certain temperatures and the truth about which moulds lose heat fastest that I didn't add to my previous posts here (not really needed to address the OP's topic). Rick and I were trying to point out to folks that the alloy temperature is a set-and-forget thing based on alloy composition and melt point, and boolit quality is obtained through all the things we can do to get the mould up to the right temperature for the conditions.



What is the best tempreature for casting bullets with WW?
Thanks,
Owen

Owen, this is one of the best questions I've seen asked here in a while, and an important one I think.

Rick pretty much covered it, and the most I can do is reiterate and expound.

Keep in mind that keeping the mould at ideal casting temp (whatever that is for a given mould, it can vary greatly) is the most important thing temperature-wise in casting. This is often overlooked, and folks who cast at a pace too slow for the mould or don't preheat their moulds somehow unwittingly compensate by turning up the alloy heat, and perpetuate the "Crank the Heat" myth. Overheating the alloy has it's own set of issues, for example tin becomes ineffective as an oxidation barrier and viscosity modifier above 750*. If you're casting with straight wheel weights with (presumably) very low tin concentration, you can run a bit hotter, but as a rule you should focus on keeping the mould hot and the alloy as cool as will reasonably cast.

How hot is hot enough for the mould? A general rule for most of my moulds is about 5-6 seconds for the sprue puddle to set, and then still cut it with the flick of a gloved finger on two-cavity moulds. This is in the "light frost" range, which is what I generally try to achieve. Opinions vary on frost, some like a little and some think it's the devil, it's mostly personal preference.

Another rule of thumb on temp, the more tin you add (up to 2% content, you shouldn't ever need more) the lower the melt temp of the alloy, and thus the lower your pot temp needs to be. Lyman recommends 100* over liquidus temp, but as another member pointed out recently in another thread it's hard to tell when all the antimony has melted completely. Your alloy may be at full liquidus at 520* in theory, but you might get best casting results at 680* and a mould at 420*.

In the end, every casting session is different, and to achieve best results you need to know a little about the physics of what you're doing and the things you can adjust so as to be able to "roll with the punches" as weather, alloy, mould conditions, and the phase of the moon :D change, rather than just remember "700* with WW alloy*, because it won't always cast best at 700*.

Hope this helps,

Gear

[then a lot of not very helpful posts and guesses, another good post by CBRick:]



Keep in mind that the composition of your mold will impact this as well. A mold that is more effecient at conducting heat away from the lead into the air will require a hotter pot to maintain temp. In general Aluminum molds will require a slightly hotter pot than steel, cast or brass molds.

I run Lee and Mountain Molds in Aluminum. And I run my pot at 700°.

Interesting. Conflicting but interesting.

Your right to run your pot at 700 degrees but a higher pot temp isn't needed to keep your molds at proper casting temp with iron, brass or aluminum. 700 degree alloy can easily keep any mold hot enough or even too hot.

As an example, your mold casts well at 450 degrees regardless of what it's made of. At 700 degrees your pot temp is 250 degrees over this proper mold temp and 250 degrees higher than proper mold temp will keep your mold at proper temp easily. No need whatsoever for a higher pot temp to maintain proper mold temp.

If your pot temp is 700 degrees and your bullets aren't forming well due to not enough heat it is not the fault of the 700 degree pot temp. It is a too cool mold, pre-heat the mold or cast faster to get the mold temp up, 700 degrees is plenty hot enough to do this.

Rick



It's astonishing to me how many people have been casting for many, many years and never snap to the fact that mould temp is everything. The only criteria for pot temperature are determined by the specific needs of the alloy itself, NOT the mould's needs.

Mould temperature is reached by preheating (either external heat source like a hot plate or dipping in the pot lead, or by casting a bunch of culls really fast until it comes up to temperature), and maintained by casting rhythm.

Bottom line with most casting alloys that contain some tin is keep it under 750* due to negating the good effects of tin and creating excessive oxidation rates, and the alloy should be enough above full liquidus to flow well, usually IME 150-200 degrees or so above melt point and at least 100 above liquidus.

If you have an aluminum or brass mould that has a high thermal conductivity, especially large-caliber moulds which have lower mass than equivalent moulds of smaller caliber, the solution to keeping them hot enough to cast well is to HURRY UP, not TURN IT UP.

Brass loses heat the fastest by far, aluminum next, then the various iron/steel alloys. This is a big consideration when ordering a mould with a particular design/shape/weight of the cavities.

If your sprue plate is disproportionate to the blocks, and the blocks lose heat faster than the plate, cast fast enough to keep the blocks at a happy temperature and invert the mould and quench the sprue plate on a towel briefly after the pour like Bruce B. and Goatlips have demonstrated. If the opposite is true, pour a bigger sprue puddle to impart more heat to the sprue plate.

Running a casting session is just like driving a car through town, a constant state of observation and correction. You just have to pay attention to what the boolits are telling you and know what things you need to adjust for correction, while keeping basic information like oxidation threshold of tin (speed limit and stopping distance, keeping with the driving analogy) as basic rules of function.

Gear

There's a three page thread going on here in Castboolits that asks "what temperature do you cast at?", in which the majority of the replies demonstrate that few people are aware of or consciously consider the difference between mould and alloy temperature and how that relates to boolit quality. I tried repeatedly to point out what I've pointed out here, but that was a different crowd I suppose.

Another good thread with high volumes of hard data about boolit weight variances, mould temperature, and alloy temperature is in here somewhere too, Goodsteel posted all about his experiences with just one mould and proved beyond a doubt that THIS STUFF MATTERS.

Gear

[cbrick]

Exactly!

I'll add to that the sprue plate temperature. It is something that few people seem to consider and yet it is as important as mold temp. The sprue plate doesn't have near the mass that the mold blocks do plus it spends time sticking out in the air cooling it rapidly. It is very difficult to get good boolit bases with a sprue plate that is too cool just as it's difficult to get good driving bands with a mold that's too cool or HP noses with HP spuds that are too cool. Always pour a generous sprue puddle to heat the plate. Don't look at it as pouring lead on the plate, look at it as pouring HEAT.

Rick

[geargnasher]

"Pouring heat" is an excellent way to visualize the sprue puddle. I like to run my sprue plates very hot and pour a very large sprue puddle that stays molten longer than the metal in the cavity. This reduces base voids and bubbles/porosity since the cooling/shrinking metal inside the mould has a liquid pool from which to pull rather than pull itself apart inside as it shrinks. If the sprue freezes last, the base will be fully formed and at full density.

Gear

[olafhardt]

This was an outstandingly good post from one of the true masters in the field. But you should know that gear is a really nice looking red head and she sells longeray at Dillards.

[alamogunr]

Slightly off topic, but maybe not too much. I seem to remember something in one of the Handloader Bullet Making annuals that used pure lead to calibrate a thermometer. Take the lead up to 700º or more and then turn off the pot and record readings every so many minutes as the lead cools. Should show a plateau in the resulting curve. I don't remember at what temp that plateau should occur but will check the next time I'm in the shop.

[Driver man]

Well written in plain English .This article should be read by every new caster and most older ones.

[DrCaveman]

Great timing here. I just made a few alloy changes and was having some issues
Couldn't figure much out, all I knew was that fill out was bad
Heating the mold waaaay more was the only fix I found
I think you just answered all my questions

Thanks! Great post

[geargnasher]

Slightly off topic, but maybe not too much. I seem to remember something in one of the Handloader Bullet Making annuals that used pure lead to calibrate a thermometer. Take the lead up to 700º or more and then turn off the pot and record readings every so many minutes as the lead cools. Should show a plateau in the resulting curve. I don't remember at what temp that plateau should occur but will check the next time I'm in the shop.

That would clear up the OP's thermometer concerns for sure. IIRC the melt point of pure lead (key word PURE!) is 621 point sumphin-sumphin degrees F. I think the freeze point is the same, and the temperature should hold steady at that temperature while the phase change completes. That Handloader article is using the same principle as determining the full-liquidus point of the metal, or the very end of the "mush phase" as the alloy melts from a solid. In case I confused anyone who's worked with pure metals or with eutectic or pseudo-eutectic boolit metal like Linotype, I failed to mention earlier that some alloys have no "mush" or "slush" phase, but change phase suddenly at one temperature like a pure metal does. I was speaking in the context of typical ternary boolit metals like wheel weights or similar. It isn't likely that many of us have cast with true eutectic metals, but have probably come close once or twice if we messed around with linotype or Lyman #2 a lot.

Gear

[alamogunr]

I need to clear something up. The article I referred to used linotype(not pure) to generate a cooling graph. The lino had a plateau at about the melting point of lino, which is 464ºF.

Also, plateau is not correct, strictly speaking. A graph generated by cooling linotype will have a descending section as the liquid starts to cool, a flat section as it changes to a solid and a further descending section as it cools to room temperature. I have to emphasize that all this came from the article. I have not done this myself.

When I mentioned pure lead, I may have been thinking about some information I saved from Bill Ferguson. I have quite a lot of it and it will take me some time to go through it.

[SSGOldfart]

this is what brings us back day after day great post Gear Please keep us updated and informed;-):coffeecom

[glockmeister]

Gear, like others, all I can do is say, ''Thanks.'' It may seem long to you but to alot of us it is short and to the point. We got the info and now to the casting area we go, thanks again, John.

[RacingRedGT]

Would like to say thanks for that awesome little write up.

[Toymaker]

Fantastic write up, simple and very easy to understand. Just in time too, because I figure on doing some casting today.

I just have one small question or issue - - - - 29˚68’27”N, 99˚22’07”W by my memory would be someplace in China, way north of Vietnam/Laos. And the 68 in 29˚68’27”N is wrong since the maximum is 59. That's what caught my eye and I looked at the rest of it.

Just teasin', Gear. ;-) Really wonderful write-up

[cbrick]

It seems that Gear is a closet communist Chinese. Who'da thunk it? :mrgreen:

Rick

[MBTcustom]

Excellent discussion.
It is very hard to separate the meat from the hide when dealing with anything regarding firearms and shooting but there are people like Gear who are actively compiling fact based on science instead of superstition, and he deserves a huge slap on the back and a free beer for not letting himself be discouraged from posting by folks who hammer nails into trees.

You just can't properly solve a problem (like temperature variances in pot vs. mold) unless you have a real understanding of what the basic problem is in the first place. Gear has identified the base problem which allows him to design a real, concise, simple, and effective means of solving the problem. That is the #1 thing that each of you should take from this. Gear is not a magician, he simply pays attention to details, and does not ignor the data. That is science plain and simple, and we should all try to follow his example no matter where we are in our proficiency. It's the only way we grow.

I am not nearly as far along, and my experiments are directed a different direction (mainly dealing with the firearms) but I did find a way to discover the ideal operating temperature for a specific mold, and it seems that most of my molds like the alloy to run at about 740 degrees if I am casting with 50/50. Surely a different alloy would prefer a different temperature, but Gear pretty much nailed how to get darn close right off the bat.
here's the thread where I had fun over Christmas break testing and experimenting:
http://castboolits.gunloads.com/showthread.php?224168-How-consistent-are-you-REALY

I just have a couple more comments about the discussion so far.
Thermometer calibrating:
Just as the molten alloy hesitates in it's temperature when making the transition from solid to liquid, water hesitates in it's transition from solid (ice) to liquid and from liquid to gas (steam). This transition from liquid to gas is the point at which water boils and that can never go higher because any water that reaches a higher temperature is released from the container in the form of steam, so the boiling water is a very consistent temperature which is 212 degrees F. That is precisely why all of our thermometers start at 200F. So that we can accurately calibrate them! I run many thermometers in my business as it is very important to hot tank bluing, and they are all calibrated with boiling water.

Mold temperature:
I was told by 45 2.1 Gear, and several others that the mold will be at the ideal temperature when you get a 3.5 second sprue puddle freeze, and that has certainly proved to be just about right for me. If it takes more than 3.5 seconds, frosty boolits are not far behind, and if it takes less than 3.5 seconds, you are headed straight for rounded corners and then wrinkles.
Regardless, it is imperative that the puddle freeze be consistent and monitored closely. I don't know if another single point of on the fly data that can be used to judge consistency as well as puddle freeze time.
The puddle freeze is able to be manipulated by counting seconds after the drop and the mold is shut, before filling the mold again.
The pace can be accelerated by the use of a fan, or by casting on cold days. Anything that helps strip the heat from the mold faster.
I actually used to touch the mold to a wet rag for 1/2 a second after every drop, but I do not recommend you do this especially with brass or aluminum molds as they are easily warped by such vicious heat control methods. It's better to count time and use a fan.

[Bullshop]

Something that helps me keep a good rhythm to maintain mold temp is at my casting bench at eye level I keep a large clock with a second hand that ticks. I find that with most molds something close to 4 casts per minute is what keeps the mold at the right temp.
I try to stay close to that 4 cast per minute even with very large multiple cavity molds. With the large ones I adjust the pot temp to get a sprue hardening time of not more than 5 seconds but still try to set the pace at 4 casts per minute.
I don't wait for the sprue to harden proper but as soon as it wont wiggle I cut it. Gear is absolutely right and is something I have said here a thousand times, its not alloy temp its mold temp that produces clean boolits.
Once you find the rhythm and start making good boolits after that point for that pot of alloy for as long as that session lasts there should be no bad boolits only good ones. If your castings have to be sorted through to find good one I consider them all bad because if there are many from that session that are visibly bad out side the ones that look OK out side most likely are not good inside.
Rhythm and mold temp work together to produce good clean well filled boolits inside and outside.

[geargnasher]

The "68 minutes" is an obvious invalid quantity intended to indicate that the coord's are fugazi. Sort of, the other parts are correct.

Gear

[MBTcustom]

Sorry, have to start a post with my phone then edit with the computer and I type slow.

[62chevy]

http://castboolits.gunloads.com/showthread.php?224168-How-consistent-are-you-REALY

I just have a couple more comments about the discussion so far.
Thermometer calibrating:
Just as the molten alloy hesitates in it's temperature when making the transition from solid to liquid, water hesitates in it's transition from solid (ice) to liquid and from liquid to gas (steam). This transition from liquid to gas is the point at which water boils and that can never go higher because any water that reaches a higher temperature is released from the container in the form of steam, so the boiling water is a very consistent temperature which is 212 degrees F. That is precisely why all of our thermometers start at 200F. So that we can accurately calibrate them! I run many thermometers in my business as it is very important to hot tank bluing, and they are all calibrated with boiling water.



Next time at casting I'll bring a pot of water to check my terminator. Don't know why I didn't think of that before. Great info on calibrating and mold temp Goodsteel.

Gear: Just outstanding info now if I can just remember half I'll be headed in the right direction. Need to buy some ink so it can be printed out for future reference.

cbRick thanks for your input.

Thanks again guys for taking the time to explain in detail. I to don't like long post but when certain members post I read 'em.

[olafhardt]

The boiling temprature of pure compounds and elements varies with pressure. Water at 3200 PSIA boils at 705○F which means a lot to people who work in power plants. Ice made from absolutely pure water freezes at 32.15○F period regardless of pressure or political views of the tester. The "triple point" of a pure compound or element which is the


temperature where solid, liquid and
vapor are present does not vary. Thus
ice, molten sulfur, pure tin and other
substances can be used as primary standards of temperature.However the purity of the stuff changes melting point as tin lowers the melting point of lead or salt melts ice. This is one example of how alloying can change the physical properties of metals. These chenges are not necessarily reversable. This can mean that the metal in your molt may not be the the metal in your pot. Some metals ere really soluable in each other, like tin and lead, antimony is not so soluble. Pure metals conduct heat and electricity better than alloys and some conduct better than others. Silver is the most conductive followed by copper then aluminum. This gives aluminum molds an faster ability to change temperature. I don't know the conductive of brass but it could be lower than copper because it has significant alloying metals mixed with copper. I don't this kind of knowledge necessary to cast. I throw coww in my pot, skim out the clips, flux, skim agian, add tin and start pouring boolits. Sometimes we get extremely technical on this forum and I worry that this and complexities that we talk about might discourage others from starting. Remember that boolits were made arround the camfire after skinning buffaloes all day.

[geargnasher]

.... I don't this kind of knowledge necessary to cast. I throw coww in my pot, skim out the clips, flux, skim agian, add tin and start pouring boolits. Sometimes we get extremely technical on this forum and I worry that this and complexities that we talk about might discourage others from starting. Remember that boolits were made arround the camfire after skinning buffaloes all day.

That's absurd. I'm not going to pick on what you do, or what makes you in particular happy, or what your standards are for yourself, but I assure you what discourages people from casting is not what you call getting "extremely technical" (seriously, how intelligent/educated do you really need to be to savvy what I wrote in my second post in this thread???), it's the disappointment/frustration from not having a clue what they're doing and failing repeatedly to make good boolits because a). they don't know where/how to find the information or b.) some know-it-all on the internet (or elsewhere) who doesn't understand it either is feeding them garbage, or c.) other factors such as a lazy mind that doom them anyway.

This site was founded on the premise of getting the BEST information together in a place where the most knowledgeable people of the craft hang out and share with each other. Some people ARE more technical than others, and there are lots of valid reasons for that. It is also very easy to tell someone "just melt lead, pour in mould, cut sprue, dump boolits, repeat, it's easy" IF you already have done it eleventy zillion times and figured out a way (whether you can explain it or not) that works for you. To a person that doesn't have much experience casting boolits, the nuances of alloy temperature, timing of mould handling operations, and what part of the process to change in order to correct various flaws in the final product is a complete mystery that only a basic fund of knowledge can fix. Ken's original idea was to make a place where people could gather and provide that knowledge for each other, not to announce that it isn't necessary to know anything about what you're doing to cast great boolits, or pretend that beeswax really fluxes your alloy, or shoot half-inch groups with nothing but a keyboard.

Arm the newbie with some simple knowledge (tools) and they can figure out the rest for themselves. If what's being talked about on this thread is too complex for them, they may want to consider a different hobby, like frisbee golf. I also know this: If anyone ever managed to cast decent boolits for their 1860 Colts over a camp fire, they had a pretty solid understanding of the importance of proper mould temperature.

Gear

[MBTcustom]

I agree with gear. People are at all different levels in this sport. True, what we talk about here is over the head of a newb, but this isn't what they need. There is a ton of more basic information for them on this sight, and a lot of encouragement. However, there are people who have been doing things the basic ways and have encountered some road blocks that are preventing them from advancing. When these road blocks are encountered, you have two options:
A. you do like I did for years. You decide that cast boolits have limitations and the people that are claiming to blow past those limitations must be exaggerating their experiences. Just put on the blinders and refuse to learn anything. (this is easy to do without even realizing that you are doing it.)
or
B. use the tools we have available at our fingertips and on our casting benches, (like thermometers, and micrometers and a clock) to tune your process to be more efficient. If you get more, then it's worth it. I used a handgun chambered in 308 Winchester to tag targets at 100 yards consistently last weekend using perfectly cast lead boolits. Never did that before. Didn't know it was possible. I had read it was possible, but there is a difference between reading and doing. The bar has been raised another peg for me.

Now, if you don't like discussions of advanced boolit making, you are not allowed to post how unnecessary it is in someone elses thread. I take as dim a view of that as if gear was to go into a complete newb's thread and start telling him what he is doing is just not good enough.
This is a place to encourage each person in their personal pursuit of the sport, whatever rung of the ladder they happen to be reaching for at the time.

[cbrick]

Sometimes we get extremely technical on this forum and I worry that this and complexities that we talk about might discourage others from starting. Remember that boolits were made arround the camfire after skinning buffaloes all day.

Perhaps we can change your thinking a little bit. As was mentioned, there is tons of entry level information on this site in every forum and quite often new casters are advised not to get too technical in the beginning. Certainly there is nowhere on the web where more encouragement to get started and to stick with it than right here at CastBoolits. Nowhere else is more effort put in to dispel old wives tales for the benefit of new casters.

That said how could the craft grow, the hobby progress if those with years of experience didn't discuss it for fear of someone new not trying casting or giving it up? This is truly the golden age of cast boolits. Better accuracy and higher velocity has been achieved in the last several years than in all the years before because of the discussions taking place, ideas exchanged and experiments being done through this forum.

Do you really think these discussions of ideas, experiments and results shouldn't take place? Take a little time and think about that.

Rick

[geargnasher]

What we're talking about here, on this thread, shouldn't be over the head of a 'newb'. If it is, we failed them somehow. After all, this thread was STARTED by an inexperienced caster looking for a simple answer to (perhaps) the wrong question.

Some members here have a tendency to freak out if advice given to a newbie involves any sort of quantification of an action, such as timing pours with a wall clock and focusing on maintaining a certain rate. This is where all the "you're overcomplicating it" criticisms originate. We're not talking about graduate-level casting techniques needed for sub-moa high-velocity shooting, we're talking about Boolit Casting 101 here, the class that comes right after the 099 class on safety fundamentals. Laying out the basic concepts and ground rules of casting boolit metal should simplify things, not make them more difficult. Of course it CAN be over-analyzed and made overly complex, for example a beginner doesn't need to start with a Waage pot, dual pid thermocouples, certified alloy, a Mihec custom mould, and a degree in metallurgy/chemistry/physics to make good boolits in short order, they just need some fundamentals, and correct ones. How is a brief explanation about how to manage pot and mould temperature with a thermometer and wall clock overly complex?

Gear

[alamogunr]

I'm not strictly a newby, but I don't spend a lot of time experimenting either. I do like to read threads like this one because even if I don't use all the information contained, I usually pick up something that helps.

Case in point is the post by cbrick(post #31) that pointed out that the sprue plate can be a source of problems. I have been struggling with just such a problem. I have a six cavity H&G #50 mold and a four cavity #50. The four cavity presents no problem. The six cavity is enough heavier that I can't get a good rhythm going. The sprue puddle solidifies before the cavities are full. I get 2-3 good boolets and the rest are just partial. Right now I'm working on a mold guide for the six cavity in the hope that it will allow me to pour faster and have a good sprue puddle to keep the temp of the plate hot.

If anyone has more suggestions, they are welcome.

[snuffy]

When I joined CB back in '07, I had been casting boolits for 35 years.

At first I didn't spend much time on here, meaning the whole forum.Until about 4 years ago, I simply heated my alloy, bottom poured it into a Lyman mold, sized in my old Lyman 450. Mostly for my SBH 44.

Since the first time I read gear's explanation of how tin oxidizes much faster above 750 degrees, I have been casting at much lower temps. After finally buying a thermometer, I saw how much variation,(temp swings), I was getting from my lee 4-20 pot. For a while I simply dealt with it by constantly mentoring, adjustment, chasing the temp.

Then I read a thread here on cast boolits forum about this thing called a PID. I asked a simple question of the thread OP, got a smart A** answer. But I insisted he tell me how to build such a control.

http://castboolits.gunloads.com/showthread.php?65330-Pid-controller-help&highlight=

Referred to the special projects forum and a thread started by horseman, I finally got it built and working. Walker77 was rude, he must have thought I was a troll!?¿

Whats my point? Yeah I ramble, but I was just pointing out how much MORE there is to learn from this forum.

BUT you have to be receptive, ready to learn and discard old habits. Case in point, I've always used a hardwood stick to tap the sprues open. I keep seeing others mention using a gloved hand to open the sprue plate. I finally quit being stubborn, tried it myself. I don't like wearing gloves while casting, but one on my right hand is okay. It works! And my molds will last longer!

Gear is patient, clear in his writing and right, (correct). He gives freely of his time and knowledge. I have learned more from him than anyone else here. cbRick, Felix, Beagle, 45 nut, there's a host of others that have also helped me and many others.

[geargnasher]

Alamogunner, are you able to cast with a large ladle over a big pot of lead on an open burner? The problem with a bottom-pour pot is they shoot a low-volume stream of high-pressure lead that splashes in the cavity and sometimes plugs the sprue hole before the cavity is filled because you just can't get enough volume out of it to keep the pace up and mould/plate hot enough to work right. A 2# Rowel ladle will give you large volume and low pressure so you can dollop each cavity full in a quick gulp without spraying lead everywhere and creating excessive turbulence in the cavity that can trap air bubbles. The large ladle will also let you get through the whole pour quickly and let you flood the whole sprue plate with alloy to keep "pouring heat" into that area as Rick put it. If you dip out of and cast over an open pot, you can flood the heck out of the top of the mould and let it sheet off the sides without making a mess like you would with a bottom pour pot.

Gear

[cbrick]

A 2# Rowel ladle will give you large volume and low pressure so you can dollop each cavity full in a quick gulp without spraying lead everywhere and creating excessive turbulence in the cavity that can trap air bubbles. The large ladle will also let you get through the whole pour quickly and let you flood the whole sprue plate with alloy to keep "pouring heat" into that area as Rick put it. If you dip out of and cast over an open pot, you can flood the heck out of the top of the mould and let it sheet off the sides without making a mess like you would with a bottom pour pot. Gear

There must be a spy camera in my shop, that or Gear is a fly on the wall cause he's been watching me cast. :coffeecom

I remember a month or so ago recommending to our giggling moderator to get a Rowell #2, he almost listened and bought a #1. [smilie=1:

Rick

[btroj]

Giggles does tend to have troubles listening and comprehending, doesn't he?

The technical part of all this matters when you want to do more than plink and play around with cast bullets.

Want great accuracy particularly at higher velocity? Long range accuracy? Want to exceed 2500 fps and have a bullet impact where it is supposed to? Want hollow points that open without blowing apart?

All those require thought and study of what needs to happen and how to make it happen.

In the end you do what it takes to get the desired results.

I've been casting for 30 years and have learned more in the last 5 years than I did the previous 25. Opened my eyes and saw what CAN be and figured it was time to work towards the goal of making the can into an IS.

[alamogunr]

Gear: I've got a pot that I use over a plumber's furnace, and a #2 Rowell. I've only used them for heavy .45-70 boolets and .475 L boolets. I guess I'll try it out on the .38 wadcutters too. If it works on those, I'll try it on the 200gr .45ACP boolets too. It should work fine on the 4 cavity MP H&G68 mold too.

That plumber's furnace and pot was another one of those things I got at work before they scrapped it out. I tend to forget about it since I've been retired 8 years and don't cast those big boolets very often.

[screamingjohnny]

Gear I've been casting 30 years. I learned some great information from your post as well as some others here. Thanks John

[45 2.1]

..... if you don't like discussions of advanced boolit making .....

Actually, all that you all have been discussing is the "basics" to cast a boolit that is actually worth trying to get a really decent repeatable group out of. Very little past that has been discussed on the site.

[olafhardt]

Sorry if I offended any of you guys. I personally think you are the heart and soul of the best and my favorite site on the internet. I just wanted to point out that one does not have to get all this technical to cast boolits nor do they need lots of equipment. I am not anywhere as experienced as probably any of you. I do have a technical background but I have no interest in high performance, accuracy, effectiveness or even self defense loads. I have found casting boolits to be a fun little hobby that can be done with some cheap stuff. I do think equipment is often over emphasized but I know lots of people love gadgets. I spent a career trying to simplify large industrial facilities and that is part of my personality. I even know what galena and think dam few of you ever cast with it unless you refined it ...........a lot.

[MBTcustom]

Actually, all that you all have been discussing is the "basics" to cast a boolit that is actually worth trying to get a really decent repeatable group out of. Very little past that has been discussed on the site.

Well you get what you pay for. Some information is cheaper to experience than to be taught.

[MBTcustom]

Sorry if I offended any of you guys. I personally think you are the heart and soul of the best and my favorite site on the internet. I just wanted to point out that one does not have to get all this technical to cast boolits nor do they need lots of equipment. I am not anywhere as experienced as probably any of you. I do have a technical background but I have no interest in high performance, accuracy, effectiveness or even self defense loads. I have found casting boolits to be a fun little hobby that can be done with some cheap stuff. I do think equipment is often over emphasized but I know lots of people love gadgets. I spent a career trying to simplify large industrial facilities and that is part of my personality. I even know what galena and think dam few of you ever cast with it unless you refined it ...........a lot.

It's not the equipment you have, it's how ya use it.

You have no interest in accuracy?
You have no interest in effectiveness?
No interest in self defence (and in the same vein "hunting") loads?

You do know that firecrackers are a cheaper way to make something go bang right?

[Quiettime]

....The problem with a bottom-pour pot is they shoot a low-volume stream of high-pressure lead that splashes in the cavity and sometimes plugs the sprue hole before the cavity is filled because you just can't get enough volume out of it to keep the pace up and mould/plate hot enough to work right. ...

BOOYAHH! And that's what I figured out today.

After an hour of casting and keeping the mold on the "hot plate" (actually I have a little mini-stove that I use, but it gets "really hot"; I put a new battery in my Ratech today only to find out it is trashed, so I still don't know the exact mold temp) and stilll having wrinkles, I finally figured out I needed to adjust the flow down a little bit and this helped a lot.

I did manage to cast about 300 nice boolits, ever-so-slightly frosty. I'm not going to tell you how many I threw back in the pot.

I also watched the pot heat up a lot closer than I have been. Using COWW ingots today rather than the range scrap ingots I had been previously using, the RCBS (not Lyman, doh! Getting old I guess) thermometer showed about 550* when they started melting. I tried running it at about "750*" for the said hour or so after that but still ended up cranking it up a bit over "900". Once I figured out the spout deal, I tried turning back down and still was getting dribbly pour and rounded bases so I turned it back up a little.

#1. I need another thermometer, at least to "check" mine.
#2. I need to get a new Ratech and/or get the mold temp probe setup from NOE (I went ahead and had my mold drilled just in case).
#3. NOE HP mold does not fit very well under the Lee 420. Could not use an ingot mold to catch the drips and they would frequently impede the movement of the mold during pour

All-in-all, a successful casting session. I kept this thread in mind and I think I am headed in the right direction.
https://scontent-a-mia.xx.fbcdn.net/hphotos-frc3/t31.0-8/1898694_818897971458010_1832903595_o.jpg

[geargnasher]

Try adjusting the valve to open more with cooler alloy. COWW usually melt around 600 F or so unless you've added some tin, then it drops a bit. Also, try casting FASTER. The hot plate/oven/preheat concept is just to get the mould going faster, the hot metal you pour in every few seconds is how you keep it hot. If the mould isn't staying hot enough, increase your speed.

Think four complete casting cycles per minute and 725F alloy. Going over 750 defeats the benefit of tin in the mix (for casting purposes) and the surface tension of the melt actually becomes stronger at that point.

The middle parts of your boolits exhibit exactly what I like to see in my own boolits (because I find it easier to get good fillout that way), a very light "frost" appearance. This means that part of the mould was up to a good casting temperature, some who prefer shiny boolits or slightly fatter boolits might say TOO hot. I notice a pour wrinkle on the HP nose and a pretty bright sheen near most of the tips, indicating that part of the mould was cooler than the middle and also indicating your pace is too slow to keep the HP pin warm enough, even with (I presume) 900 degree alloy. Same for the bases. Remember, it's all about MOULD TEMPERATURE, which means if the mould is too cold, cast FASTER. This is not meant as negative criticism, just pointing out how to give yourself clues to observing temperature differences in the mould just by observing the boolit's appearance "on the fly" as you are casting them. All shiny, all frosty, no matter as long as you like them and can get them formed fully.

Now, go shoot some of those things! I got a handful of them myself yesterday from another member and I'm going to be slinging them through a single-shot .30-30 hopefully tomorrow....

Gear

[leftiye]

Having your mold up to a correct temp consistently via use of a mold heater in your casting cycle will remove the need to cast frantically. It will allow frosting (or not, as you desire) at almost any lead temperature irregardless. This though 700 to 750 seems to werk best. It will further keep the hollow point pin, and the nose of the mold and cavity - at that same temp as the reas of the mold. One can approach the "keep 'em all" situation in casting by this technique. But it isn't a high volume way to go.

[olafhardt]

It's not the equipment you have, it's how ya use it.

You have no interest in accuracy?
You have no interest in effectiveness?
No interest in self defence (and in the same vein "hunting") loads?

You do know that firecrackers are a cheaper way to make something go bang right?

Goodsteel, I love to plink.

If anyone wants a good cheap way to precisely check a thermometer, thermocouple or any other temperature reading device, get a brand new Lee 4 pound pot and some pure tin. The melting temp of PURE tin is 449.5 °F. As long as the tin is pure this melting point does not vary and is a widely accepted primary temperature standard.

[Recluse]

There's a three page thread going on here in Castboolits that asks "what temperature do you cast at?", in which the majority of the replies demonstrate that few people are aware of or consciously consider the difference between mould and alloy temperature and how that relates to boolit quality.

Gear

I adjust the temperature of my alloy to best suit my mold.

Old-time casters understand what I just wrote perfectly, so let me explain to some of the newer folks.

I have different molds that have different requirements so far as heat is concerned and how well/how long they will hold a temp, etc. I've found the easiest way for me to get consistent boolits is to keep my alloy at consistent temps to facilitate the mold temperature staying consistent.

With my Lee ProIV pot, which I ladle cast from, I do not have a PID so instead I rely on my thermometer to tell me what the alloy is doing. The alloy temp will fluctuate depending on how full or how empty the pot is, which in turn will affect my mold temp (transfer of heat) which in turn affects the consistency of my boolits.

So, if I keep my alloy for my beloved Lee TL158SWC two-banger at a reading of around 775F, adjusting the temp if and as needed as I go through alloy, AND I keep my casting cadence and rhythm and timing consistent (thank you, BruceB!), then my mold stays at a consistent temp that allows it to produce superb boolits.

I have another mold for RN230 grain boolits that doesn't need as hot of an alloy, plus this being a steel mold PLUS producing a larger boolit with a larger mass, the mold temp can easily get hotter than I like and not produce the quality of boolits I want.

So with this mold, I slow my casting cadence down so as to allow a bit of cooling in between casts. Likewise, I carefully monitor the alloy temp.

I'm with Gear on the mold temperature, but in my case, I've also learned how to manipulate it or regulate it with alloy temperature as the two do work hand-in-hand. The mistake is to place too much, or even all, emphasis on one factor or the other. Most new casters are concerned with alloy temp. Older casters are more concerned with mold temp (and condition).

Good stuff.

:coffee:

[leftiye]

I adjust my mold temperature to make slightly frosted boolits with 700 degree alloy. Mold heater. A hotter mold makes better boolits (so long as melt isn't too hot ). I'm thinking of putting a PID into the aluminum plate on my hotplate in order to reduce temp swings of the mold. I don't worry about cadence. I inspect (with magnification) as I go, no throwing half of them back when I'm done. Mold's the right temp, lead's the right temp.

[Quiettime]

... The mistake is to place too much, or even all, emphasis on one factor or the other. ...

It is a lot to manage at once. I'm reminded of my mother, cooking a big meal and all the things she has going at once.

One thing I have come to understand is that how you set everything up is critical to success. Dean Grennell wrote about "therbligs" in The ABC's of Reloading and it makes a big difference when you have everything arranged correctly. Right now I'm using a folding table but I'm looking forward to custom-building a casting bench.

But enough typing, it's time to make the boolits!

[Whitespider]

Ooooopps... double post.

[Whitespider]

Gadget technology is overrated.

I don't use a thermometer... don't even own one... never have.
My heat source is the electric burners on an old kitchen range.
I dip alloy from old cast iron cookware.
Although I do have a bonafied boolit casting ladle, I often use an old cast iron open-top ladle.
I regulate the temperature of both my alloy and mold by intuition, gut-feeling and what I see dropping from the mold.
My boolits are shiny, well filled-out and consistent in both weight and diameter.

Oh, and speaking of Dean Grennell and The ABC's of Reloading...
He wrote in one of those editions that there are some people who, for whatever reason, are incapable of casting a decent boolit no matter how hard they try... LOL‼
I remember when I read that I prayed I wasn't one of those people.
*
*

[Quiettime]

That's awesome. Getting a thermomter helped me immensely. I couldn't get any consistency before. Now I'm starting to be very happy with my boolits. I would never recommend to a beginner to not use one.

[woodbutcher]

:bigsmyl2: Hi gear.Great post.Outsanding information.Some of the posts that I see here and at other sites that I frequent,remind me of an old joke.
There was a professor at a well known place of "higher education"that would always leave his students with a little gem at the end of each class.One day he said,Students,remember this."Anything conceived by the mind of man is possible".
From the back of the room comes this voice that says"Heyyyyyyyy professor,did ya ever try to strike a match on a marsh mellow".
Good luck.Have fun.Be safe.
Leo

[Whitespider]

Getting a thermomter helped me immensely. ... I would never recommend to a beginner to not use one.

No, I wouldn't either... but at the same time I likely wouldn't tell them they need one.

I mean, knowing that an alloy temperature of 700° works best when the shop is 65° with 40% relative humidity in April does me no good in July or November... heck, chances are it does me no good tomorrow. With the pot a bit over ¾ full (20 pounds or so) I have a base setting on the stove burner I use... which is really all a thermometer would do for me, supply me with a base setting. I adjust from there as conditions and/or mold dictate... sometimes hotter, sometimes cooler. There's a small fan mounted on the wall for cooling the mold or sprue as/if needed, such as when I begin to see some frosting. Sometimes I hold the mold with the sprue plate facing the fan, sometimes the mold bottom, sometimes one side or the other, sometimes full, sometimes empty, sometimes open, sometimes closed, sometimes every pour, sometimes every 2 or 3, anywhere from a 2-count to a 10-count (actually, I mount a ticktock clock above the fan)... it all depends on what I see dropping. I don't care to adjust casting rate except as a last resort; as a ladle caster I have a rate that's comfortable and works for me... not "speed casting", but not dilly-dallying either (although, doing the fan thing does adjust it slightly). But I like shiny boolits, and that's what I adjust for... shiny, well filed out, sharp cornered boolits.

Seriously... I'm unable to see where an alloy thermometer would be of any sort of aid to me.
But I do believe a mold thermometer, say some sort of wireless constant read-out, would be immensely advantageous... maybe some day as technology progresses.
*

[Quiettime]

Seriously... I'm unable to see where an alloy thermometer would be of any sort of aid to me.
But I do believe a mold thermometer, say some sort of wireless constant read-out, would be immensely advantageous... maybe some day as technology progresses.
*

It might help you get the shiny boolits you desire quicker without having to cast and adjust as much. Also might help you keep from destroying a batch with zinc contamination when smelting or keep from oxidizing the expensive tin out of your melt.

You made me laugh about the humidity in April, and it's true, whatever you think you know, there are always other outside forces acting on your results. The proof really is in the pudding and if what you're doing is working then you're GTG...but someone else reading the forum trying to learn how to do it may not have the same luck, and that's what Geargnasher is trying to prevent.

That said, I did learn yesterday that my RCBS thermometer wasn't as off as I thought. The Tel Tru I ordered from NOE actually read about 30 or 40 degrees higher than the RCBS...so I really was running 1000 degree metal.

I also learned from my new mold block thermometer that it takes a little bit longer to get the mold up to temp with my "hot plate" than I thought. I was probably starting at <200 degree temp so that's why it took so long to get good boolits. With 750 degree lead the mold seemed to "like" running between 400 and 425 degrees. Below that I seemed to get a lot of rounded bases.

I'd like to see a little lower mold temp. Still can't really get the drip-o-matic adjusted to suit...either pours too much and splashes out of the mold or drips constantly...but it was a good session with about a quart and a half of good boolits. Still learning but I know a helluva lot more than I did a month ago

[dikman]

Gadget technology is overrated.

Not for me, I love my gadgets :D.

[Lead]

"Frosting" is an effect caused by two things in combination: The presence of antimony in the mix, and a very hot mould.

The temperature of the metal going into the mould has zero to do with whether or not the boolit surfaces will have the "frosted" appearance, that is 100% a function of mould block temperature and cooling rate, or rather the SLOW cooling rate, of the alloy. The more slowly an antimonial alloy cools, the more time the antimony dendrite crystals have to form lattices, and the appearance of a textured surface becomes present.

For example, I can literally pour 800-degree wheel-weight metal into a 200-degree mould and get shiny, wrinkled boolits with rounded edges. I can also pour 650-degree wheel weight metal into a 450-degree mould and make boolits that are so frosted and undersized that they appear as rough and dull as freshly-broken cast iron, or appear as if they were sand blasted. The difference is the temperature of the MOULD, not the alloy. And, of course, the presence of some antimony in the mix. Tin/lead alloy or pure lead always casts fairly shiny, regardless of mould temperature or alloy temperature.

The general rule for most of the ternary (lead, antimony, tin) alloys that we scrounge up for making boolits is to run the pot below 750 degrees F., or really about 100-150 degrees hotter than the fully-liquid point, and to preheat the moulds somehow (dip a corner in the melt for a while, set across top of pot for a few minutes, or improvise a "mould oven" using a hot plate and metal box) so they come up to casting temperature faster or start out at casting temperature. THEN, as you cast, maintain a pace that is brisk enough to keep the mould hot enough for good fillout.

Casting good boolits is all about consistency. Constant pot temperature is important, this is what your thermostat and thermometer are for. Constant mould temperature is even more important, and that is controlled simply by adjusting the timing of the various pouring, waiting for sprue to set, cutting, opening, dumping, closing, and refilling operations. Casting boolits is like driving a car on the highway, you have to constantly make slight corrections to steering, throttle, brake, etc. and watch your mirrors, the road, anticipate hills and valleys to keep the speed consistent and in the "zone" that you want to be.

You'll have to experiment with timing operations and pouring stream adjustment, technique, sprue puddle size, etc. while watching for frosting, rounded edges, filled bases, air bubbles/voids in the bases, wrinkles, shiny spots, frosted bands/shiny noses, sprue flashover time to give yourself clues about what is working and not working with a particular mould, alloy, and atmospheric condition.



Here's a quick and dirty method that works every time. Turn on the pot and start melting your alloy. Stir it with a spoon as soon as it starts to get mushy and watch the thermometer. Once the metal thins out like thin porridge, keep a close eye on temperature, it should remain constant as the phase changes. Once the last bits of grainy metal go away, the temperature should start to rise again (the metal is past the phase platau). Record the phase plateau temperature and add, say, 150F to it. Allow the alloy to reach this temperature and adjust the pot to maintain it. Spoon in a layer of pine sawdust on top of the melt and stir the alloy gently to flux and reduce oxides. Skim if you want, or not. Dip a corner of your mould down int he metal and hold it there until the alloy no longer sticks to the blocks when you withdraw it, this could take anywhere from 30 seconds to two minutes. Dip the tip of the sprue plate in the alloy too, for about ten seconds, then close the mould and start casting. The mould should suck the pot temperature down 50 or so degrees depending on the size of the mould. Fill, cut, and dump the first few castings quickly and glance at the boolits. If shiny and wrinkled, keep casting culls as fast as you can until they start to fill out and get an even, satin frost all over. From this point on, you can play with the timing and sprue puddle size to control mould block and sprue plate temperature to keep the mould temperature and boolit quality even from nose to tip.

This works with any alloy, any pot, any pouring technique, and any mould (except non-antimony alloys won't frost, you just look for sharp edges and good fillout with those) and any weather. Don't forget to glance at the pot temperature once in a while and make sure it stays 100-150 above the fully-liquid point that you recorded first thing. It's all up to mould temperature and technique after that, and trust me, quit dinking around with pot temperature, it is not going to do you any good.

One more thing, to emphasize what MT Gianni wrote, IF your thermometer is off even 200 degrees, if you do as I described above, it won't matter because you only want to obtain an alloy temperature that is a certain amount above fully liquidus with ANY alloy, and your thermometer is good enough to give you that valuable reference point even if it is not giving you an exactly accurate temperature reading.

Gear

Very good info there I've been casting a year but new here,thanx gear

[popper]

I have a Lee dripper with PID control, use the hot plate to preheat the moulds. Previously had been running 720F for 4x Al. moulds. I pour really big puddles to begin to get the sprue plate up to temp faster, then try for smaller puddle. Now I just got a 2x Al. with the slotted plate. At 720F, hard to get good fill. I dropped to 680-690F and WOW. First - minor dripping! More than 650 165gr rifle boolits, maybe a dozen bad pours - yes, make sure the plate is all the way closed. Culled for rounded shank base - 26 poor - barely visible. I'll shoot these sans check anyway. All this in 2 hrs including fill & refill time & dump sprue cuts back, plus a rest break for me. Experiment and find what the mould really wants! Temp makes a difference as much as size.

[ghh3rd]

I dip alloy from old cast iron cookware.

Hope it doesn't get passed down to someone who decides to cook food on it :shock: I use an old Lodge pot to clean my lead in and have marked it so no one will ever use it for food again.

Just sayin...

[popper]

OK, tried something in the last session. I've started casting at a lower alloy temp, got tired of counting to 30 or so & just counted ~5 after the sprue made it's last color change. Cut with gloved hand. Really good cuts, no tears or streaks. Really nice bases.

[Grizzly Adams]

:castmine::violin:

[MBTcustom]

OK, tried something in the last session. I've started casting at a lower alloy temp, got tired of counting to 30 or so & just counted ~5 after the sprue made it's last color change. Cut with gloved hand. Really good cuts, no tears or streaks. Really nice bases.

Sounds like a thermometer would change your world.

[popper]

Uh, it's a PID controlled pot! My comment was that I now run ~690-700 vs the 720 I was running (same alloy), and cut after the second color change. Cutting right after the first color change gave some tears & streaks - not really good bases. And I don't have to count so much.

[tsignal]

I bought a digital thermometer(looks like a small multimeter) that takes K-thermocouples. used an old flexible microphone neck to hold it in the pot, reads fine and gives me accurate temp readings. Funny how different molds pour better at different temps

[RugerFanOH]

Can an infrared thermometer like the HF model be used?

http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-60725.html

[62chevy]

Can an infrared thermometer like the HF model be used?

http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-60725.html

If it works it would only give you surface temp which is not what you want. But it might be good for mold temp.

[dragon813gt]

Can an infrared thermometer like the HF model be used?

http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-60725.html

Search my name for threads I created. I performed a test w/ an infrared thermometer like the one you posted. As well as a high end, it's one of the lower models but still plenty expensive, FLIR camera. The verdict is that they don't work. I go into more detail in the thread.

[RugerFanOH]

Thanks dragon, excellent work in that 2013 post!

Any advice on thermocouples vs analog thermometers?

[doc1876]

This was an outstandingly good post from one of the true masters in the field. But you should know that gear is a really nice looking red head and she sells longeray at Dillards.


Is she married??

[Twmaster]

I cast my first boolits today. 9MM, .45 and .309

Like has been mentioned in this thread I learned the hard way mold temp is so important. My first go round with the 9MM mold did not yield any good boolits.

I then went to a new Lee .45 230 grain mold. After allowing the mold to get good and hot over the pot I began making good boolits after a couple of first pours.

What I now see, after reading this thread, is I should have been casting faster to maintain mold temp. I had my Lyman pot at 780F.

Now armed with info from this thread I'll look at stepping up the pace and lowering the temp in the pot a little.

I want to thank you all for the wealth of real world knowledge.

[cbrick]

Are you using a thermometer? The dial on the pot does not relate to actual pot temp, if yours does you have the only such pot. If your using an alloy with tin in it your pot temp should not be over 700-720 as tin will both oxidize rapidly and not be able to do what it's in the alloy to do at 750 degrees.

Rick

[62chevy]

:goodpost:Thanks Rick, very good info.

[Twmaster]

Rick,

Thanks for the reply. The temp scale on this this pot does not seem to be marked in degrees. I had a new Lyman thermometer in the stew. It read 780F.

Your point about the tin is understood and during my next casting session I'll be mindful of your comments.

ETA a pic!

http://www.twmaster.com/stuff/shoot/reload/cast/castblast.jpg

[KuunLB]

i didn't go through all the replies so forgive me if this is a repeat question. you mentioned pine sawdust. Would i use this with flux or without? Is the sawdust for fluxing specific to pine? or perhaps could cedar or other woods be used?

thanks for a great article, lots of good info, definitely a sticky

[cbrick]

Welcome to CastBoolits KuunLB,

The sawdust is the flux and the reducer, no need for any additional flux. Pine is the popular and smells good but any wood sawdust that will burn down to carbon. It's the carbon that does both the fluxing and reducing.

Hope this helps.

Rick

[btroj]

Welcome to CastBoolits KuunLB,

The sawdust is the flux and the reducer, no need for any additional flux. Pine is the popular and smells good but any wood sawdust that will burn down to carbon. It's the carbon that does both the fluxing and reducing.

Hope this helps.

Rick

Technically the reduction comes as the wood is converted to charcoal. Low order combustion is best, it produces lots of reducing gasses.

When Rick speaks of fluxing, do what I do.

121181

[cbrick]

Technically the reduction comes as the wood is converted to charcoal. Low order combustion is best, it produces lots of reducing gasses.

When Rick speaks of fluxing, do what I do. http://smileyshack.files.wordpress.com/2010/12/sbiting_100-1081.gif

From "Ingot to Target" by Glen E. Fryxell - chapter 4.

The benefits of sawdust are that it‘s a sacrificial reductant that can reduce any oxidized tin back to the metallic state, and it‘s cheap enough that the caster can use enough to form an effective barrier layer to protect the alloy from subsequent oxidation. What’s more, as the sawdust chars on top of the melt, it forms activated carbon, which is a high surface area, porous sorbent material that has a large number of binding sites capable of binding Lewis acid cations like Ca, Zn and Al. So it not only keeps the tin reduced and in solution, but it effectively scavenges those impurities that raise the surface tension and viscosity of the alloy (Al, Zn and Ca), keeping the alloy in top shape for making good bullets.


Rick

[btroj]

Link is fixed now.

[62chevy]

i didn't go through all the replies so forgive me if this is a repeat question. you mentioned pine sawdust. Would i use this with flux or without? Is the sawdust for fluxing specific to pine? or perhaps could cedar or other woods be used?

thanks for a great article, lots of good info, definitely a sticky

I use cedar with great results. Most prefer the high resin content of pine and the way it smells but cedar smells good too.

[KuunLB]

From "Ingot to Target" by Glen E. Fryxell - chapter 4.

The benefits of sawdust are that it‘s a sacrificial reductant that can reduce any oxidized tin back to the metallic state, and it‘s cheap enough that the caster can use enough to form an effective barrier layer to protect the alloy from subsequent oxidation. What’s more, as the sawdust chars on top of the melt, it forms activated carbon, which is a high surface area, porous sorbent material that has a large number of binding sites capable of binding Lewis acid cations like Ca, Zn and Al. So it not only keeps the tin reduced and in solution, but it effectively scavenges those impurities that raise the surface tension and viscosity of the alloy (Al, Zn and Ca), keeping the alloy in top shape for making good bullets.


Rick

i'm actually reading this in pdf form, the writer is one well educated individual, making my head hurt but i'm getting alot of good info. going to be top of my read list until it's done.

[cbrick]

Yes he is, here is snip from a post I made in another thread on Dr. Fryxell.

In short, he is: Chief Scientist; Pacific Northwest National Laboratory, Adjunct Professor of Chemistry, One of the countries leading scientists in nanotechnology, been published in scientific journal's to many to list, author of several books in his field, over 2,700 citations by his peers and far more.

Here is an index to many of his articles, if you enjoy the book you should like these also.

http://www.lasc.us/ArticlesFryxell.htm

Rick

[larryw]

I sure want to thank all of you, especially Gear for the info here.
I am reading a ton & printing a ton, so I don't forget where I saw it.
Been loading for 40 years, just now starting to cast. I have yet to
pour my first lead, got more reading to do. Just getting things
together I need. will get a thermometer the end of the month.
Thank's again for this info, it is much appreciated...

[geargnasher]

That's why we're here, Larry, to put out the good info with detailed explanations as best we understand it and dispel myths so everyone can benefit. Not all of us agree all the time, and there are many things that can be done to the same effect lots of different ways, but not all.

Gear

[62chevy]

I sure want to thank all of you, especially Gear for the info here.
I am reading a ton & printing a ton, so I don't forget where I saw it.
Been loading for 40 years, just now starting to cast. I have yet to
pour my first lead, got more reading to do. Just getting things
together I need. will get a thermometer the end of the month.
Thank's again for this info, it is much appreciated...


Awesome Larry glad to see you found castboolits. Can't wait to see your first cast boolits.

[larryw]

Hey Chevy, good to see 'ya. [smilie=s: You bet I'll be posting pics of 'em all over LOL.
End of the month I'll have my thermometer & my little bitty lead stash will
go away real fast LMAO....

[62chevy]

Hey Chevy, good to see 'ya. [smilie=s: You bet I'll be posting pics of 'em all over LOL.
End of the month I'll have my thermometer & my little bitty lead stash will
go away real fast LMAO....

LOL cool I'll be looking forward to seeing them. Anyways this was this was my first try at casting. http://castboolits.gunloads.com/showthread.php?194764-Cast-my-first-Boolits-ever-yesterday

[KuunLB]

That's why we're here, Larry, to put out the good info with detailed explanations as best we understand it and dispel myths so everyone can benefit. Not all of us agree all the time, and there are many things that can be done to the same effect lots of different ways, but not all.

Gear

i'm glad there are people like you and s-3, mooseman, and everyone who frequents the chat who take the time to answer questions us noobs have. I was about to buy my first lee 6cavity 9mm mold, i did a search on casting and found this site, i waited 2 weeks because i read about beretta 92's on this site liking .358 better than .356's and so after i learned more i decided on a lee 2 cavity .358 mold that i can use to cast for my 9mm and my .357. so yeah, thankyou for all your contributions!!

i've cast my first ingots from WW's last weekend. and let me tell you i really enjoyed it. i can't wait to start casting boolits! :)

[firewhenready7]

Just starting to cast and I found the post very helpful. Thanks Gear

[Mike9793]

A thermometer is a standard. If your shows water boils @ 300 F it isn't accurate. That doesn't keep you from noting you get your best bullets when it reads XXX and taking your melt to that point. Accuracy isn't really needed for most boolit making just repeatability. Pure lead melts @ 621.5 F so get some pure and see what it does with your t/stat. make sure it is pure but those are your reference points.

funny this week I was casting .54 cal pedersolli mold and found that I was on 7 and was getting wrinkles turned it to 8 and dropped the mold about a inch from the flow tip and watched it fill to the top than tapped it slightly and once hardened open in up and I get a perfect bullet ever time. It took me about fifty bullets to figure this out but it works for me.

[hillbilly571]

lots of good info here that helped me understand a few of the problms im having. i'v got 983434857687359834763 questions but i promice not to ask them all here now. there is a thermometer in my very near future. i knew heat the alloy, heat the mold, lift handle to fill mold, cut sprue, tap boolits out, refill mold. had no clue there was a good temp to cast at, or that mold temp played a LARGE part though i did notice many of my boolits came out wrinkled or not full and ended up goin back in the pot. for now im using lee molds, 1 is a .401 175gr for a .40 s&w, the other is a .356 125gr for a 9mm. those for the .40 fall right out but the ones for the 9mm do lot of sticking. i read somewhere on here about filling th cavities, cutting the sprue and drilling a hole in the boolit for a hexheaded sheetmetal screw and using a drill to rotate the boolit in the cavity to polish things up. also i read that maybe the hammer handle im using ain't the best thing to use for cutting the sprue?? it works well but could i be damaging the sprue plate?? or the blocks??

thanks to everyon for all the info here on the site, glad i joined

Joe

[MBTcustom]

A hammer handle is fine, but a small rubber hammer might be better? As long as you don't hit the blocks too hard it'll be fine.
Remember that it does take about as much time on a hotplate to properly preheat your mold as it does for your lead pot to properly melt your alloy and bring it up to operating temperature (about 20-25 minutes).
An easy way to find out the right heat setting on your hot plate is to tak a good guess at it and let it heat up while the lead melts.
Once everything is up to temp, take the mold off the hot plate and fill it.
Watch how long it takes for the puddle to freeze.
If it takes more than 5 seconds, turn down your hotplate a little, leave the mold on it for 10 minutes, and try it again.
If it takes 4 seconds, leave it alone.
If it takes less than 4, turn it up a little.

Of course, at operating temperature, you want to be seeing a 3 second sprue freeze, but you need to start with a little too much heat, push the first three drops aside, then start piling up the good-uns.

[62chevy]

Watch how long it takes for the puddle to freeze.
If it takes more than 5 seconds, turn down your hotplate a little, leave the mold on it for 10 minutes, and try it again.
If it takes 4 seconds, leave it alone.
If it takes less than 4, turn it up a little.



Thanks I need to try this next time.

[snuffy]

lots of good info here that helped me understand a few of the problems i'm having. i've got 983434857687359834763 questions but i promise not to ask them all here now. there is a thermometer in my very near future. i knew heat the alloy, heat the mold, lift handle to fill mold, cut sprue, tap boolits out, refill mold. had no clue there was a good temp to cast at, or that mold temp played a LARGE part though i did notice many of my boolits came out wrinkled or not full and ended up going back in the pot. for now i'm using lee molds, 1 is a .401 175gr for a .40 s&w, the other is a .356 125gr for a 9mm. those for the .40 fall right out but the ones for the 9mm do lot of sticking. i read somewhere on here about filling th cavities, cutting the sprue and drilling a hole in the boolit for a hexheaded sheet metal screw and using a drill to rotate the boolit in the cavity to polish things up. also i read that maybe the hammer handle i'm using ain't the best thing to use for cutting the sprue?? it works well but could i be damaging the sprue plate?? or the blocks??

thanks to everyone for all the info here on the site, glad i joined

Joe

Joe, welcome to the forum. I used to use a hardwood stick to strike the sprue plate to cut the sprue. I often saw many others here that used a welders glove to simply twist the sprue plate open to cut the sprues. I finally tried it, as I already had the gloves for smelting. It works! I always worried that I might be damaging the mold by hitting it, now no worries! I was being stubborn for not trying it before.

As for the drilling/sheet metal screw process, it's called LEEmenting. It also takes some sort of abrasive as well as turning the boolit in the cavity. Many simply use toothpaste. If you have some very fine valve grinding compound, that works as well. I use 600 grit fire lapping compound. Don't spin it too fast, you only want to remove the burrs in the mold cavity that are holding onto the boolit.

As for heat of the alloy, intil you get a thermometer, you won't know what the numbers on your furnaces dial actually mean. ((This is assuming that you are using some sort of electric casting furnace.)) You should never need to go above 750 degrees with a wheel weight alloy, or the equivalent. As you said and goodsteel said, the mold is more important to have up to temp than the lead alloy. The 3-5 second sprue puddle freeze rule is a good one. This allows the boolit to keep drawing lead from the sprue puddle as it cools and this is when you get complete fill-out of the boolit.

Please keep asking questions. That's what this forum is all about, providing a place to come to get straight answers to well thought out questions.

[hillbilly571]

Thanks again. Yes, I am using an electric furnace at this time and using the "hardball" ingots i ordered from midway (6%, 2%, 92%). Next casting session will be a lil different than this last one as I'll have a thermometer and will be armed with some timing and temperature knowledge. My last session was about 3 hours long with a total of about 400 boolits though a lil over half of those went back in the pot. Visually the ones i kept looked pretty good but, they will be individually run across the scale to check the weight. Anything severly off will be put back in the pot for another round.

I'll give the gloved hand appraoch a shot when cutting sprues

Leementing. Is there a type of toothpaste to avoid or will about any work?? Should this be done with the mold block hot, warm, cold??

Thanks again for all the info

Joe

[mongoose33]

I can't remember who suggested this or I'd give them credit, but the suggestion was to use a rubber mallet as a sprue knocker and hinge banger. Because the "whap" is not as sharp, and there is a bit of reverberation in the rubber, it shakes out boolits more effectively when tapping the hinge of the handles. It's what I'm using now.

[Slow Elk 45/70]

Yup, should be a sticky , not many of us are going to go to the effort Gear did to make the information usable for all. Semper FI:cbpour::awesome::awesome:

[Black Chrome]

Read the .pdf form this weekend before I have even cast my first bullet. I learned a lot and probably saved a ton of money by not buying the wrong stuff right off of the bat. Thanks again for this forum!

[GONRA]

For decades (on and off) GONRA has used any nice lookin' "lumber scrap" stick
to "strike the sprue plate to cut the sprue". Verks Just Fine.

If it sprue sticks, just wack it again - usually boolit will "just fall off".
If it doesn't offgefall, just cast again (hopefully with yer BOTTOM POUR furnace) -
and if metal is hot enuf to properly cast, mold refills Just Fine.

[popper]

Stick works fine to cut but how hard is it on an Al. mould and how square is the base? If the sprue is hard enough to require a 'whack' it tends to raise the plate when cutting and is hard on the corner of the mould.

[AJG]

quiettime,

I am new for casting as well (I use a propane Camping stove and Lee molds) and have allways a wrinkle Problem no matter what I do to get the lead hot and as well the mold.

I found the proper pouring technique is crucial. I live in an 220Volt Country as well and was thinking in getting the Lee 220 V furnace as well in order to get rid of the wrinkles. But I can live witht the wrinkled bullets.

What did you do to get rid of wrinkled bullets?

[62chevy]

quiettime,

I am new for casting as well (I use a propane Camping stove and Lee molds) and have allways a wrinkle Problem no matter what I do to get the lead hot and as well the mold.

I found the proper pouring technique is crucial. I live in an 220Volt Country as well and was thinking in getting the Lee 220 V furnace as well in order to get rid of the wrinkles. But I can live witht the wrinkled bullets.

What did you do to get rid of wrinkled bullets?
Cleaned the daylights out of them and used a propane torch to get them up to temp.
Go easy on the torch though and the sprue plate may need a bit more heat than the mold.

[STIHL]

I just joined here to say thank you for all the helpful information here In This post. Been lurking a while and reading a lot.

[james nicholson]

Welcome to the forum STIHL, hope you pick up a lot of good info. Keep shooting, Jim

[fivefang]

Gear, that's a excellent post, I've been casting since '55, 38/40 win. '73, in the fowling shot a decade ago or so "Kitty-Litter" was often mentioned, has that lost it's appeal? nobody seems to mention it in Quick Posts, Fivefang

[Chris C]

"Frosting" is an effect caused by two things in combination: The presence of antimony in the mix, and a very hot mould.

The temperature of the metal going into the mould has zero to do with whether or not the boolit surfaces will have the "frosted" appearance, that is 100% a function of mould block temperature and cooling rate, or rather the SLOW cooling rate, of the alloy. The more slowly an antimonial alloy cools, the more time the antimony dendrite crystals have to form lattices, and the appearance of a textured surface becomes present.

For example, I can literally pour 800-degree wheel-weight metal into a 200-degree mould and get shiny, wrinkled boolits with rounded edges. I can also pour 650-degree wheel weight metal into a 450-degree mould and make boolits that are so frosted and undersized that they appear as rough and dull as freshly-broken cast iron, or appear as if they were sand blasted. The difference is the temperature of the MOULD, not the alloy. And, of course, the presence of some antimony in the mix. Tin/lead alloy or pure lead always casts fairly shiny, regardless of mould temperature or alloy temperature.

The general rule for most of the ternary (lead, antimony, tin) alloys that we scrounge up for making boolits is to run the pot below 750 degrees F., or really about 100-150 degrees hotter than the fully-liquid point, and to preheat the moulds somehow (dip a corner in the melt for a while, set across top of pot for a few minutes, or improvise a "mould oven" using a hot plate and metal box) so they come up to casting temperature faster or start out at casting temperature. THEN, as you cast, maintain a pace that is brisk enough to keep the mould hot enough for good fillout.

Casting good boolits is all about consistency. Constant pot temperature is important, this is what your thermostat and thermometer are for. Constant mould temperature is even more important, and that is controlled simply by adjusting the timing of the various pouring, waiting for sprue to set, cutting, opening, dumping, closing, and refilling operations. Casting boolits is like driving a car on the highway, you have to constantly make slight corrections to steering, throttle, brake, etc. and watch your mirrors, the road, anticipate hills and valleys to keep the speed consistent and in the "zone" that you want to be.

You'll have to experiment with timing operations and pouring stream adjustment, technique, sprue puddle size, etc. while watching for frosting, rounded edges, filled bases, air bubbles/voids in the bases, wrinkles, shiny spots, frosted bands/shiny noses, sprue flashover time to give yourself clues about what is working and not working with a particular mould, alloy, and atmospheric condition.



Here's a quick and dirty method that works every time. Turn on the pot and start melting your alloy. Stir it with a spoon as soon as it starts to get mushy and watch the thermometer. Once the metal thins out like thin porridge, keep a close eye on temperature, it should remain constant as the phase changes. Once the last bits of grainy metal go away, the temperature should start to rise again (the metal is past the phase platau). Record the phase plateau temperature and add, say, 150F to it. Allow the alloy to reach this temperature and adjust the pot to maintain it. Spoon in a layer of pine sawdust on top of the melt and stir the alloy gently to flux and reduce oxides. Skim if you want, or not. Dip a corner of your mould down int he metal and hold it there until the alloy no longer sticks to the blocks when you withdraw it, this could take anywhere from 30 seconds to two minutes. Dip the tip of the sprue plate in the alloy too, for about ten seconds, then close the mould and start casting. The mould should suck the pot temperature down 50 or so degrees depending on the size of the mould. Fill, cut, and dump the first few castings quickly and glance at the boolits. If shiny and wrinkled, keep casting culls as fast as you can until they start to fill out and get an even, satin frost all over. From this point on, you can play with the timing and sprue puddle size to control mould block and sprue plate temperature to keep the mould temperature and boolit quality even from nose to tip.

This works with any alloy, any pot, any pouring technique, and any mould (except non-antimony alloys won't frost, you just look for sharp edges and good fillout with those) and any weather. Don't forget to glance at the pot temperature once in a while and make sure it stays 100-150 above the fully-liquid point that you recorded first thing. It's all up to mould temperature and technique after that, and trust me, quit dinking around with pot temperature, it is not going to do you any good.

One more thing, to emphasize what MT Gianni wrote, IF your thermometer is off even 200 degrees, if you do as I described above, it won't matter because you only want to obtain an alloy temperature that is a certain amount above fully liquidus with ANY alloy, and your thermometer is good enough to give you that valuable reference point even if it is not giving you an exactly accurate temperature reading.

Gear

Gear, I want to thank you for taking the time to write this out. I keep a link to this thread and to Goodsteel's "Consistency Applied" on my desktop and any time things get quiet around the house I read them. I glean something new each time. As a newbie I find your information extremely helpful.

[Soundguy]

Nice write-up!

[bbogue1]

Check out the Etekcity Lasergrip 1080 Non-contact Digital Laser Infrared Thermometer -58℉～1022℉ for $19 on Amazon.

[snuffy]

Check out the Etekcity Lasergrip 1080 Non-contact Digital Laser Infrared Thermometer -58℉～1022℉ for $19 on Amazon.



The laser temp thermometers like the above, don't work well when shined on the surface of freshly fluxed "shiny alloy. The laser bounces, is reflected, by the mirror like surface of the lead. Gives a false reading.

I too have one of the H.F. el-cheapo laser temp dohickies, when I use mine I drop a steel nut into the lead to give a black target for the laser.

I really don't need it much, my pot is controlled by my pid, which gives me constant temp readings. I've tested the pid, I trust it's readings.

[Bob in St. Louis]

Infrared units do not work for casting (I spent money before I found out they don't work).
The lead is too reflective and the "beam" bounces off.
Read post #4 >> HERE << (http://castboolits.gunloads.com/showthread.php?324269-Infrared-thermometer-will-it-work-for-casting), and follow his link.

[Bob in St. Louis]

I wasn't going to post in this thread, as it's chock full of great information, and I have more failure stories than I do good advise.....
But... that being said, I've watched this fellows technique with regard to timing and tapping of the mould.
In my (novice) opinion, this guy is worth watching:
https://youtu.be/IBkMRhB6RqM

[Phlier]

I wasn't going to post in this thread, as it's chock full of great information, and I have more failure stories than I do good advise.....
But... that being said, I've watched this fellows technique with regard to timing and tapping of the mould.
In my (novice) opinion, this guy is worth watching:
https://youtu.be/IBkMRhB6RqM

I really enjoy FortuneCookie45LC's videos. Great guy.

[Bob in St. Louis]

Thanks, glad you like it.
Yea, he's pretty cool and very knowledgeable.

[Kent Fowler]

"Frosting" is an effect caused by two things in combination: The presence of antimony in the mix, and a very hot mould.

The temperature of the metal going into the mould has zero to do with whether or not the boolit surfaces will have the "frosted" appearance, that is 100% a function of mould block temperature and cooling rate, or rather the SLOW cooling rate, of the alloy. The more slowly an antimonial alloy cools, the more time the antimony dendrite crystals have to form lattices, and the appearance of a textured surface becomes present.

For example, I can literally pour 800-degree wheel-weight metal into a 200-degree mould and get shiny, wrinkled boolits with rounded edges. I can also pour 650-degree wheel weight metal into a 450-degree mould and make boolits that are so frosted and undersized that they appear as rough and dull as freshly-broken cast iron, or appear as if they were sand blasted. The difference is the temperature of the MOULD, not the alloy. And, of course, the presence of some antimony in the mix. Tin/lead alloy or pure lead always casts fairly shiny, regardless of mould temperature or alloy temperature.

The general rule for most of the ternary (lead, antimony, tin) alloys that we scrounge up for making boolits is to run the pot below 750 degrees F., or really about 100-150 degrees hotter than the fully-liquid point, and to preheat the moulds somehow (dip a corner in the melt for a while, set across top of pot for a few minutes, or improvise a "mould oven" using a hot plate and metal box) so they come up to casting temperature faster or start out at casting temperature. THEN, as you cast, maintain a pace that is brisk enough to keep the mould hot enough for good fillout.

Casting good boolits is all about consistency. Constant pot temperature is important, this is what your thermostat and thermometer are for. Constant mould temperature is even more important, and that is controlled simply by adjusting the timing of the various pouring, waiting for sprue to set, cutting, opening, dumping, closing, and refilling operations. Casting boolits is like driving a car on the highway, you have to constantly make slight corrections to steering, throttle, brake, etc. and watch your mirrors, the road, anticipate hills and valleys to keep the speed consistent and in the "zone" that you want to be.

You'll have to experiment with timing operations and pouring stream adjustment, technique, sprue puddle size, etc. while watching for frosting, rounded edges, filled bases, air bubbles/voids in the bases, wrinkles, shiny spots, frosted bands/shiny noses, sprue flashover time to give yourself clues about what is working and not working with a particular mould, alloy, and atmospheric condition.



Here's a quick and dirty method that works every time. Turn on the pot and start melting your alloy. Stir it with a spoon as soon as it starts to get mushy and watch the thermometer. Once the metal thins out like thin porridge, keep a close eye on temperature, it should remain constant as the phase changes. Once the last bits of grainy metal go away, the temperature should start to rise again (the metal is past the phase platau). Record the phase plateau temperature and add, say, 150F to it. Allow the alloy to reach this temperature and adjust the pot to maintain it. Spoon in a layer of pine sawdust on top of the melt and stir the alloy gently to flux and reduce oxides. Skim if you want, or not. Dip a corner of your mould down int he metal and hold it there until the alloy no longer sticks to the blocks when you withdraw it, this could take anywhere from 30 seconds to two minutes. Dip the tip of the sprue plate in the alloy too, for about ten seconds, then close the mould and start casting. The mould should suck the pot temperature down 50 or so degrees depending on the size of the mould. Fill, cut, and dump the first few castings quickly and glance at the boolits. If shiny and wrinkled, keep casting culls as fast as you can until they start to fill out and get an even, satin frost all over. From this point on, you can play with the timing and sprue puddle size to control mould block and sprue plate temperature to keep the mould temperature and boolit quality even from nose to tip.

This works with any alloy, any pot, any pouring technique, and any mould (except non-antimony alloys won't frost, you just look for sharp edges and good fillout with those) and any weather. Don't forget to glance at the pot temperature once in a while and make sure it stays 100-150 above the fully-liquid point that you recorded first thing. It's all up to mould temperature and technique after that, and trust me, quit dinking around with pot temperature, it is not going to do you any good.

One more thing, to emphasize what MT Gianni wrote, IF your thermometer is off even 200 degrees, if you do as I described above, it won't matter because you only want to obtain an alloy temperature that is a certain amount above fully liquidus with ANY alloy, and your thermometer is good enough to give you that valuable reference point even if it is not giving you an exactly accurate temperature reading.

Gear

This post from Gear ought to have it's own separate sticky and be required reading for beginning casters, before they ever fire up their first pot of alloy. I hadn't cast in a lot of years, until last weekend when my SOL wanted to learn about the craft. I was using two Ideal iron molds and fell into the trap of raising the pot temp until I got "good" bullets. Common sense took over after I had raised the PID temp to 810* in order to cure the wrinkles. Shut the operation down and started perusing the stickies and found Gears post most excellent treatise on mold temperature. Bought a hot plate the next morning and preheated the mold to 325*. Started casting and all bullets were perfect. The knowledge existing on Cast Boolits is phenomenal. Thanks, Gear
T

[shafer44]

good job. good post

[byrd45900]

I have been using Tel-Tru thermometers for 5 years.They last longer and stay accurate.Usually cheaper then the competiton too.

[Bazoo]

I too have been blessed by Gear's post. Thank you. Thanks to the OP and others too.

[mold maker]

Personal knowledge of facts and techniques, translated into simple terms, presented free.
Thanks GEAR

[pistonwolf]

Good info on your pouring technique, esp the alloy temp trick.

[jwlegal]

The timing on this post is way off as it looks like the last post was a couple of years ago. I'm going to ask anyway just in case someone is still looking this over. You certainly can get bad info from a lot of sources, but I was taught that frosting meant the boolit was too hot and that it would shatter on impact when shot. Now I'm seeing this post that the boolit should be frosted. Of course that causes me to ask....if the boolit is frosted will it maintain its integrity when it hits the target? I understand this also has to do with how much antimony is in the mix as I understand too much will also make the boolit fragment. Anyone still around that can set me straight on this?

[44Blam]

The timing on this post is way off as it looks like the last post was a couple of years ago. I'm going to ask anyway just in case someone is still looking this over. You certainly can get bad info from a lot of sources, but I was taught that frosting meant the boolit was too hot and that it would shatter on impact when shot. Now I'm seeing this post that the boolit should be frosted. Of course that causes me to ask....if the boolit is frosted will it maintain its integrity when it hits the target? I understand this also has to do with how much antimony is in the mix as I understand too much will also make the boolit fragment. Anyone still around that can set me straight on this?

Frosting happens when both your mold and alloy temp are fairly high when casting. It has nothing to do with hardness/brittleness. It will affect size/weight, though.
Hardness is a result of alloy and time and boolits really only become brittle when VERY hard - you might be able to get this with pure linotype? Maybe pure monotype?

[fn1889m]

https://uploads.tapatalk-cdn.com/20200413/efd44c2af5264788b9fa66ef0b0f9375.jpg

This was a good thread. Thank you. Beginner here. Same pot, same session, different temperatures. These are the extremes. Most were in between.

I spent my last two casting sessions experimenting with temperature, trying a variety of settings. I learned that turning down the pot temperature helps. Slightly frosted is better than very frosted looking bullets. Not above 6 on the Lee 20# pot dial. And slowing down the casting frequency. Casting with range lead.


Sent from my iPhone using Tapatalk Pro

[kevin c]

That boolit on the right is nigh on perfect. That very light matte frosting (or perhaps just a tiny bit more with my alloy, molds and technique) is what I want to see to get in the groove where it rains all perfect slugs. Congrats!

ETA: you may find that the alloy temp varies even at the same setting. One reason is that as the pot emptys, the coil heats up the remaining alloy more. Another is adding ingots or a bunch of sprues all at once which drops the temp significantly.

[fn1889m]

I intentionally ran the temp dial up and down the range. I also slowed down my casting speed to lower the temperature of the mold. I am trying to identify the target temperature. I’m just a beginner.


Sent from my iPhone using Tapatalk Pro

[kevin c]

You're learning fast!

Lot of beginners hope to be taught or read about optimal technique, but conditions vary so much, even from session to session for the same caster, finding what works well takes experimenting.

Carry on, and keep on having fun!

[MOC031]

From "Ingot to Target" by Glen E. Fryxell - chapter 4.

The benefits of sawdust are that it‘s a sacrificial reductant that can reduce any oxidized tin back to the metallic state, and it‘s cheap enough that the caster can use enough to form an effective barrier layer to protect the alloy from subsequent oxidation. What’s more, as the sawdust chars on top of the melt, it forms activated carbon, which is a high surface area, porous sorbent material that has a large number of binding sites capable of binding Lewis acid cations like Ca, Zn and Al. So it not only keeps the tin reduced and in solution, but it effectively scavenges those impurities that raise the surface tension and viscosity of the alloy (Al, Zn and Ca), keeping the alloy in top shape for making good bullets.


Rick

Hi Rick, from another Rick:

Just browsing stickies this morning as it is raining hard enough out there that I'm not interested in going hunting. Always something new to learn (or at least think about) browsing stickies.

WAAAAYYYY back in the days of Fidonet prior to the WWW, Ken Mollohan helped me get beyond the stage of just dumping something molten into a mould and believing whatever resulted was kind of what you get with bullet casting.

Back then, Ken got me started fluxing with carnuba wax flakes. Along with a lot of other changes I made. I've been pretty happy with my bullets since Ken mentored me along until I was being thoughtful in my casting and expecting much more in what I got for results.

So... that said: how does carnuba wax stack up against sawdust for fluxing. I have a lifetime supply of carnuba wax here, but if there's a chance that sawdust instead will result in better results, there's a sawmill out where I do a lot of my elk and moose hunting where I can go for sawdust. Or alternately, my wife the aggressive carpenter makes LOTS of fine sawdust versus the sawmill sawdust.

And thanks for the informative posts on temperature that I've been scrolling through today.

Rick

[303Guy]

Interesting comment on the effects of sawdust. Does the source of the sawdust make a difference, like pine versus other? On waxes, I have found stearic acid (a wax) to be a real good flux. When pine sawdust does nothing, stearic acid will release silver drops of metal. It also works as a solder flux. But the ability of sawdust to remove calcium zinc and aluminum is something I did not know about. On the other hand, stearic acid burns clean (but is not too cheap).

[MOC031]

Interesting comment on the effects of sawdust. Does the source of the sawdust make a difference, like pine versus other? On waxes, I have found stearic acid (a wax) to be a real good flux.
I don't know whether flake carnuba wax is a flux, or a reducer, or whatever. Reducer, I'm thinking. I'll guess Ken Mollohan, with his chemistry background, would have pointed me at stearic acid instead of carnuba wax if he would have thought it better.

But I did dive head first into that .pdf book written by Glen Frye. So I guess I've provided my own answer to the question I asked Rick - sawdust has the additional advantage of removing other metal contaminants that carnuba wax won't.

As my alloy supply is pretty clean stuff, I won't worry too much for now about not using something that will also clean the alloy in the pot of contaminating metals. Once I've gone through the carnuba, then I guess I'll go bug my wife for her cedar sawdust.

[303Guy]

Carnauba wax is made up of acid and diesters of acid among other things so it makes sense that it would be a flux. I don't recall actually trying it in my melt pot or for soldering though. I'll give carnauba go when next I have an opportunity.

I just tried stearic because I had some and didn't think I had a use for it and since wax is used as a flux in melting pots, I threw some in to see what would happen and it separated metal from the dross very well. Then when I had no soldering flux I thought I would give it a try and found it makes a great soldering flux too.

[HM8485]

I had a similar experience and wish I had seen Gear's post years ago. I stopped worrying about the thermometer and cast close to maximum on the rheostat. In both my pots. My RCBS thermometer reads high and so does my genuine Chineseum thermometer I bought 20 years ago. The important temperature for any heat is the one that consistently gives you good boolits as Gear states. Thanks for the posting.

[cloverleaffrank]

Great information! Years of casting experience as I can tell. Thank you

[Devodale]

Gears post is exactly the info I searched this site for and found it quickly as well! Thank you!!!

[Bob in St. Louis]

Welcome!

[greenjoytj]

I usually get spots of frosting on my cast bullets. As far as I known their isn’t any antimony in my alloy just lead and tin. The small patches of frosting haven’t caused me any problems.
After lubri-sizing and loading in cartridges cases I wipe any lube that may have gotten oozed up out of the case. Wiping always restores a bright shiny appearance to the bullet.

I have a Lyman digital thermometer it works good. It just can’t be left in the melt for for more than 1 or 2 minutes because the heat travels up the metal probe and will start to soften the plastic fitting that connects the probe to the wire that plugs into the thermometer case.

[Stuckcase]

My casting world changed when I bought a PID. My bullets are so consistent now. I can regulate my mold temperature as well as have a visual tossing spruces back in and cooling the mold off at times. If you don’t have a PID set up—it’s as paramount to good bullets as buying good molds

[Astocks2622]

Incredibly simple. Still helping us newbies 8 years later. thanks to Gear for taking the time to write this up.

[Wooserco]

Resurrecting an old thread. All that I can say is Thank You to Gear!

Over the last 24 hours, allowing the pot and molds to cool I've come to the conclusion that he is spot on! I have my pot set to 720 (degrees. I set the mold on top of the pot to pre-heat. When the pot comes up to temp (120 degrees above liquidous) and I start casting, regardless of mold it's two casts and boolits start raining.

Thanks to all that have contributed. Gear, you've reinforced all that was taught to me (that I forgot) from my mentor Lester. May he rest in peace. A Korean War veteran that really never received the appreciation that these men deserve. I include the Viet Nam vets in this. We all owe a debt of gratitude to these veterans. Sadly, many are no longer with us.

[Quiettime]

Resurrecting an old thread. All that I can say is Thank You.....

Thanks to all that have contributed.

I'm astounded that this thread is still going and that so many have learned so much (myself included). I've been away for a while but I just bought a new mould and going to start making some new boolits.

Cheers!

[rbuck351]

I just learned a couple of things from Gears long and very good post. Thanks Gear. I have been casting for about 55 years and have learned a lot by doing everything wrong until I stumble onto something that works.

I cast for around 40th years without a lead thermometer. I simply set the pot up to max and then started turning the temp down until the frosting just stopped. This worked fairly well for most molds. I now use a thermometer and set the pot at about 750 and preheat my molds. If I get frosting at that point, I use a small fan pointed toward where I'm holding the mold while cutting the sprue. Apparently mold temp is more important than I realized. I will also be checking the accuracy of my thermometer.