WW's Not Giving Sharp Bands

[ColColt]

I got my new "born again" Lyman 429421 mold from Erik yesterday and this afternoon decided to try it out. The three bands had been slightly enlarged and cut to perfection and I scrubbed it real good with Joy and water before casting and then let it warm up on my hot plate. My first alloy was 10# of ww's and 3 oz of tin. I had trouble getting the bands to fill out sharply so went up to about 675 degrees-still didn't look/feel right.

Next, I made up a batch of 50-50 lead/Linotype and dropped the temp back to around 650 and had better results with sharper bands. Why the difference? Is it the antimony in Linotype that helps fill out these bands more sharply than just tin alone as with most ww's? I had to up the temperature with the ww's and tin alloy and still didn't get frosted bullets but the bands weren't as sharp either. I used a lead thermometer to keep check of the temperature all the way through.

[onondaga]

Either of your alloys has plenty of tin for good fill-out. The higher the tin percentage the lower the melt temp becomes, so your temp changes don't jive to me. I believe your fill-out problem is related to casting cadence not being fast enough to maintain mold temperature. You will need to cast and drop at least 3 times a minute and 4 if possible to maintain mold temperature for good fill-out. A flow stream length longer than 1/2 inch from your ladle or spout to sprue gate cools metal enough to cause poor fill-out also so if your stream is long, correct that.

Adjusting pot temperature higher does not improve bullet fill-out if the mold is not hot enough and maintained at operating temperature by casting cadence. If you can not cast fast enough to get frosted boolits with your pot at 650 - 675, you are NOT casting fast enough and your casting cadence is too slow. You likely will not get good fill-out until you pick up your speed no matter how hot your pot is.

Stop looking at boolits till your pot is done and don't add sprues to the pot as you work, that only cools the pot and adds oxides from the sprues. Just cast. Check your boolits while your sprues and new ingots are melting for the next run.

Gary

[ColColt]

WW's in themselves don't have any tin that I know of. That's why I added about 3% but this alloy contains no antimony. Linotype had approximately 4% I believe but also has 12% or so of antimony and I attributed that to better fill out of the bands since WW's + 3% tin has none.

I adjust the bar on the Lee 4-20 pot so that the mold is about 1/2"-5/8# away from the spout and that seems to work pretty good. The amount of boolits per minute is about the same with all alloys so, I don't think speed was a part of the quotient as for this problem. It's sort of odd in that one side of the top band may have been sharp but the other side wasn't...weird. I did get some respectable boolits after about 20 or so but still not as well defined and sharp as with the lead/Linotype alloy.

I don't cut the spruce until I see it turn dull grey whatever time that takes...five seconds or 15 seconds. It all depends on the alloy and mold temp. Maybe it was just a fluke as I don't recall having that problem before. I haven't used ww's all that much but mostly use 50/50 lead and Linotype for about BHN15. If I wanted it softer, just added more lead. I've had an abundance of Linotype for years due to working in the printing business many years ago and got quite a bit of it that I made into 50/50 mixes but still have the type by itself to mix whenever I need it. WW's are hard to come by in my neck of the woods and a 5 gallon bucket will usually yield only about 25 pounds of it if you're lucky and the rest steel, iron and other junk. What I currently have is from Kathie and it checks out on average as BHN9.4...at least my sample do.

You did hit upon a valid point and one I'm guilty of-added sprues to the pot while I work. It's an old habit that needs breaking.

[onondaga]

OK, there you go, you gave me a key phrase to help get you more answers:

"It's sort of odd in that one side of the top band may have been sharp but the other side wasn't...weird."

There is a specific reason and correction for this. The zone type thermal differences in mold areas are called cold spots or hot spots. They are both caused by the same reason. You are getting turbulence and gurgling in your pour causing it to heat your mold unevenly. This is a classic symptom and easily corrected by modifying your pour technique. Typically this is caused by dead center pouring through the sprue gate hole. Back splatter in the mold causes a turbulence repeatedly in a similar fashion that heats the mold unevenly. The repeated hot and cold zones effect fill out and shrinkage in a repeated fashion when the same pour technique is repeated.

Swirl casting will eliminate the hot and cold spots by controlling the flow into the mold to evenly distribute thermodynamics in your mold:

The best way to begin swirl casting is to safely elevate your casting pot with good support and get the pour spout at eye level while you are seated at your bench because you need a clear view to swirl cast.

Adjust your mold guide for a 1/4 to 1/2" flow length, no longer.

When you slide your mold on the guide under the spout tip up one side of the mold about 5 degrees. and have the mold located so that the flow is not centered but is half the diameter of the flow off center and the flow hits part of the higher side of the sprue gate sloping funnel wall.

This will leave half the sprue gate hole clear for air to exit as metal flows in.

Most importantly, between the tilt and the off center pour a swirling stream flow is initiated to the metal flowing into your mold. There will be no turbulent backwash or gurgling to set up hot spots or cold spots because the metal swirls.

You need a good view to do this well and it will take practice to develop the skill well, but it will make a big difference in improving your casting quality.

Some molds aren't fussy at all how you pour them, but when you get cold spots or hot spots and uneven fill out in zones that is a clear indication to start swirl casting.

Gary
(Retired Casting Analyst)

[geargnasher]

Either of your alloys has plenty of tin for good fill-out. The higher the tin percentage the lower the melt temp becomes, so your temp changes don't jive to me. I believe your fill-out problem is related to casting cadence not being fast enough to maintain mold temperature. You will need to cast and drop at least 3 times a minute and 4 if possible to maintain mold temperature for good fill-out. A flow stream length longer than 1/2 inch from your ladle or spout to sprue gate cools metal enough to cause poor fill-out also so if your stream is long, correct that.

Adjusting pot temperature higher does not improve bullet fill-out if the mold is not hot enough and maintained at operating temperature by casting cadence. If you can not cast fast enough to get frosted boolits with your pot at 650 - 675, you are NOT casting fast enough and your casting cadence is too slow. You likely will not get good fill-out until you pick up your speed no matter how hot your pot is.

Stop looking at boolits till your pot is done and don't add sprues to the pot as you work, that only cools the pot and adds oxides from the sprues. Just cast. Check your boolits while your sprues and new ingots are melting for the next run.

Gary

+1 GARY!

ColColt, try to clear your mind, and listen more to what Gary posted here. By what you've posted you already have learned a bunch of things incorrectly, and your speculations are even further off-base, and you're bound to get frustrated. He told you everything you need to know, just study it until you understand what he said in each of the three paragraphs. It ought to be a sticky.

Gear

[onondaga]

You also mentioned color change as the indicator you use to time cutting your sprue. WATCH the puddle of molten metal on the sprue plate closely. The puddle should be as large as you can balance to keep your sprueplate hot. Your own heartbeat pulse will vibrate the puddle visibly. When the vibration stops-cut the sprue- the color doesn't matter, you have solidification occurring when the vibrations are stopping.

A good size puddle will start cooling around it's outer edge first and then concentrically toward the sprue gate hole. Finally the vibrations will stop as a dimple goes down and stops over the gate. Cut!

Gary

[ColColt]

I have two molds that do this. Sometimes half of one of the boolits will be shiny and the other side of it will be frosty or at least part of it will be. It leaves you thinking do I back off the temp or turn it up a bit. I try and cast hot enough to get all bands filled out and usually that's around 650 depending on alloy.

I didn't know there was any special technique to pouring from a bottom pour furnace... you just place the mold under the spout around half an inch or so and pour and go to the next cavity. I've had to tilt the mold forward a little filling one hole and the back a bit for the other one to keep the alloy from spilling over on the sides or back of the block. However, I did center it as best I could see. These instructions are quite a revelation. Use to I'd place the mold right up against the spout and pour but that doesn't leave much of a sprue and I've had hot liquid lead squirt back at me with that method so abandoned it for just cause.

Another thing is I open the "throttle" to pour quickly-no half way to slow the speed down. Once one side of the mold is filled I leave a small puddle, stop half a second and go and do likewise to the other side. I've tried it that way and I've tried just a continuous pour as filling the front cavity and moving the mold forward a little to fill the back one. I don't know if that all makes any difference or not.

I'm going to look over this again and reread as the methods I'm not use to entirely but, I'm certainly open to instructions make no mistake about that. As in all things there's a right way a wrong way and a I've almost got it right way. I may fall in the latter. As mentioned earlier, I only have two molds like this but, it can be a headache when they're brought out to produce. My thanks for these comments and be assured they are taken to heart. And, I thought I knew all I needed about casting boolits but, in instances such as this, I don't think so.

[plainsman456]

I have found that angling the lead stream to one side often cures that problem.
Found out by accident on day when I didn't have my glasses on.Who knew.

[Pat I.]

You could just turn the heat up until your alloy is 760 or 770 degrees and I'll bet your problems with poor fill out go away. Dull looking bullets are a good thing when casting with WWs as long as they're dull looking all over.

[SharpsShooter]

Turn up the heat! You are just playing at 650. I don't even look at the pot until the temp is nearly 800! You won't hurt a thing. Heat!

SS

[Billwnr]

Turn up the heat! You are just playing at 650. I don't even look at the pot until the temp is nearly 800! You won't hurt a thing. Heat!

SS


:drinks: I agree wholeheartedly. I'd say crank the temp up to at least 750 degrees but either 750 or 800 will serve you nicely. Anything lower than 670 degrees is going to result in some level of frustration and lots of rejected bullets.

But.... if you are only shooting 25-50 yards with a handgun, a lot of junk bullets shoot acceptedly good.

[onondaga]

Turning the heat up won't help, it is the mold temperature that controls the fill-out. If it is fluid, it pours. Some casters try to compensate for insufficient casting speed by cranking up the heat. You can go high enough to oxidize the tin in your alloy as it flows out of the spout over 800 degrees and that still will not warm up your mold enough if your casting speed is too slow.

Ideal pot temp is 100 degrees above fluidus of your alloy, Ideal mold temperature is 100 degrees below fluidus of your alloy. You can pre-heat your mold to exactly that temp and it will cast the first boolit well but if you don't cast fast enough the mold will cool. If you cast too fast the boolits will frost from an over heated mold.

Casting is a balancing act with temperatures and technique and the methods that work best have been historically recorded for thousands of years since the ancient Egyptians cast jewelry. Swirl casting information was published in the textbooks of the first American Dental colleges related to casting Dental crowns and bridges in gold. I have been an educator in that area.

Your puddle size on the sprue plate experiments are very relevant to your learning more also. Sprue plate puddle size also effects maintaining the temperature of the sprue plate. Bigger is better when trying to keep operating temperature good and constant. A small puddle will not keep your sprue plate as hot as the mold when your mold temperature is good from correct casting speed. Multiple cavity molds can be poured without stopping the flow if you are handy enough to get the metal in the holes right and control your puddle size quickly and balance it. CowboyT videos are a wonderful example of multiple cavity pouring and puddle size control with his 6 cavity molds. I envy his skill.

Don't worry about overflow, work with an ingot mold or shallow pan under your pouring area on the pot base. Add the spills to the next melt with your cut sprues and ingots.

Gary

[onondaga]

You mention trying different flow rates with the flow adjuster on your pot. Lee instructions mention gradually increasing the flow as the pot level drops to compensate for the lowering of pressure as the weight of the fluid metal decreases toward the pot bottom in a casting session. That can help you maintain a more constant flow rate.

It is interesting to discover and note that flow rate becomes less important when mold temperature is tightly controlled. Some casters have such perfect casting cadence speed naturally by their skill level that they never adjust the flow rate because the don't need to with their mold temperature being kept so even. Turning it down if you are getting splashing on your face as you mentioned is perfect common sense. That will happen with a full pot and a maximum flow setting.

Gary

[Pat I.]

Man I never knew pouring melted wheel weights into a 60 dollar mould could be so complicated. I might have to give this hobby up and take up something simple like brain surgery.

[ColColt]

The only time I've had to go 750-800 degrees was way back when Iuse to cast those large thumb size mini balls for the 58 caliber Zouave. With the cherry in the bottom for the hollow cavity and the fact that you were using pure lead there was no alternative if you expected to get good boolits. Other than that, I've tried to stay at or near the melting point for lead plus a little over.


You mention trying different flow rates with the flow adjuster on your pot.

No, Gary, what I had in reference to was two methods of pouring from the bottom spout. One was as I currently do and that's with the mold about 1/2" or so from the spout and the other was to actually hold the mold under the spout where it's actually touching the spout with no air gap. I haven't tried much adjusting with the screw on the pot.

[Reloader06]

Excellent post. Should fix a couple of minor problems for me. Thanks Gary.

Matt

[SharpsShooter]

Turning the heat up won't help, it is the mold temperature that controls the fill-out. If it is fluid, it pours. Some casters try to compensate for insufficient casting speed by cranking up the heat. You can go high enough to oxidize the tin in your alloy as it flows out of the spout
Gary

Gary,.

You are writing in absolutism. Heat of the alloy does help and produces a byproduct of heat within the mould blocks themselves. A speedy caster might run a lower temperature successfully, however it is not wise to counsel someone to cast faster unless they are dozing between pours. Hasty hand actions that the individual is not accustomed to are a recipe for harm when handling molten metals.

It is better to run hotter and at a pace the caster is comfortable with that risk injury. A seasoned caster can adjust heat to meet his or her desired rate of output and produce flawless bullets. if low temps work for you then by all means use them, but don't paint yourself in the corner by stating something doesn't work.

SS

[geargnasher]

Good grief, where did all you "crank up the pot temp" peope come from? Are you really trying to help this man or confuse him so much that he'll never get it right? I'm sure you folks are getting the results you desire from your methods or you wouldn't recommend them, but I disagree very strongly with all of you, especially since we're trying to help ColColt solve a problem, and there is a lot to casting with such a hot alloy that NONE of you bothered to explain to him, and just taking that one piece of information isn't going to help. I doubt any of you understand the reasons why I think what you're doing isn't really the best way to help a less experienced caster, so I'll outline it for you, and maybe we'll all learn something. Since my points are so often missed, I'll try to make them two or three times in the following:

The "absolutism" that Gary is trying to convey has very, very sound chemical and physical reasons:

Boolit quality is a product of MOULD TEMPERATURE, NOT POT TEMPERATURE. There are good guidelines for determining pot temperature, and they all are based upon THE COMPOSITION OF THE ALLOY.

MOULD TEMPERATURE is controlled by casting pace, (number of pours per minute), ambient temperature, air motion in the casting area, and humidity, and to a lesser degree the temperature of the metal going into it.

POT temperature should be maintained somewhere in the neighborhood of 100 degrees F over the FULL liquidus point of the alloy, because excessive heat destroys the oxygen-shielding effects of tin in the mix, and that's the whole reason tin is there in most cases (exceptions being binary lead/tin alloy, where the tin also adds a measure of strength to the lead). With pure lead, you can run it as hot as you want, an often need to go 200 or more degrees above 621 to get moulds to fill well, but there are no other alloys to oxidize out or to ruin in the process, so feel free to crank it up.

The oxygen-shielding effect of tin is destroyed at temps above about 750 degrees, this is well documented in many popular books. The oxidation rate of tin starts at the point that tin or the Sb/Sn intermetallic becomes liquid in the mix and increases exponentially as the pot temperature is increased. Lead oxidation occurs too, but at a lower rate, and since the proportion of lead is so much higher it is hardly noticeable if any is lost.

Tin and antimony dross (or oxidize) out as the surface of the melt faster than lead does, and you can actually deplete the alloy of tin and to an extent antimony in a very short time. Ask any old printer about what happens to linotype alloy after it's been repeatedly cast, melted, and skimmed. Those guys didn't do anything to reduce their oxides back into elements, so they just threw away the dross and added bits of antimony/tin mix to replenish the lost metals over time. "Over time" can be very significant to a caster. If you add 2% tin to your mix and run the melt at 800 degrees, you can literally dross out half of it before the end of a session. That is very significant, especially if you ladle-pour and skim frequently rather than reduce the oxides with sawdust or similar and skim the ash.

Think it doesn't matter? Well, it can. If you shoot at long distances small variances in alloy can matter a great deal. Someone shooting WW in a .45 automatic at ten yards will never know. Heck, the latter could shoot half-filled-out boolits and probably never see the difference on paper. The point is, good habits based upon the laws of physics and chemistry of the metals we work with will yield better results no matter the application. If you're going to do this, why not do the best you can?

Most casters that have to "crank up the heat" with common metals like WW to get good fillout are simply not getting their moulds hot enough, and are doing their alloys harm in the process. Running an overheated alloy and casting too slow is a poor way to keep mould temperature up, and keeping mould temperature up it the key to good boolits. One day when they use those bad habits for casting .30-caliber boolits with which they hope to shoot tiny groups they won't understand why they can't. The reason will be that the consistency of composition, hardness, fillout, and temper (when water quenching, especially) is terrible because they just run the pot wide open and cast at a sloppy, irregular pace while the alloy in their pot is changing from metal to metal oxide.

Now, since it's so often misunderstood, let me say it again: Adjusting pot temperature to compensate for poor fillout is absolutely the OPPOSITE of what one should really do. For one thing, it introduces another swinging variable to the already long list of variables involved with casting boolits. For another, it's bad for the alloy, as I explained above. Set the pot to the temperature that is best for the alloy's composition, AND MAINTAIN IT THERE. Period. Preheat the mould to save time, and then start casting, fast and furious until the wrinkles go away and you start to get good fillout. If the mould cavity(ies) are clean of ANY grease or oil, there will be a point where it gets hot enough for the boolits to fill out properly and cleanly. At that point, maintain that casting pace for the whole session, only making slight adjustments as needed to keep the mould in its "sweet spot", whatever it is. You will find it, and then you will know, it's different with just about every type of mould and boolit design, not to mention alloy composition.

A general rule I've found, with WW alloy and similar, a pot temp of about 650-675 degrees and a pace of three to four pours a minute is about what it takes to keep the mould hot enough for perfect fillout and a light satin frost, the kind of frost that wipes right off with a dry rag leaving mirror-shiny underneath. You can get away with 725 degrees and two pours a minute, and if that works better for you, then fine. 800 degrees and one or two pours a minute ain't the best way to go with most common Pb/Sb/Sn alloys, and that IS an absolute. Don't believe me? Go read any good casting manual, or remelt and reduce your dross pile with sawdust and so a specific gravity test on the resulting elemental metal, you will find 50 to 80% of it is TIN.

I say it again: Frost and fillout is a product of MOULD temperature, not POT temperature. Don't believe me? Run your pot of WW metal to 900 degrees. Grab a mould off the shelf and pour your metal into it, hammer the sprue off with a large mallet (because it will set instantly), and you will have a shiny, wrinkled, half-filled boolit. Now, take the same mould, let the alloy cool until it is JUST above full liquidus, ten degrees above slush or so (probably around 575 degrees), preheat your mould by sticking it in the melt for a minute, then pour your cool alloy into the mould. In about ten seconds when the boolit finally freezes, you will have a light grey, sandblasted-looking super-frosty boolit. Mould temperature makes the boolit frosty, fillout or not, no matter how hot or cool your alloy is.

Gear

[cbrick]

On pot temp I have to agree completely, totally and 110% with gary. EDIT TO ADD: and with Gear also.

Some people it seems just plain and simple HATE tin, will do everything they can to get rid of it. Even before the tin is completely gone they insist on making certain that any that may be left cannot do what it is in the melt to do, reduce oxidation.

These same people it seems cannot grasp the concept that a 700 degree pot temp is far more than enough heat to get and keep the mold temp at a proper casting temp which is well below a 700 degree melt temp.

These same people it seems cannot grasp the concept that a 800 degree + pot temp will also slow down casting because you have little choice but to wait for 800 degree alloy to cool to 550-580 (depending on alloy) BEFORE you can open the sprue. The concept that it takes the sprue longer to cool to solidus from 800 degrees than it does from 700 degrees does not apply.

These same people it seems cannot grasp the concept that there are legitimate reasons for not running the alloy any hotter than needed and try to encourage others to do as they do, they try to discourage others from learning any of the metallurgy of bullet casting.

I take a Goldi Locks approach to WW alloy pot temp. I cast WW + 2% Sn at 700 degrees, not too hot to hurt the tin or need to wait to long for the sprue to cool. Not too hot, not too cool, its just right.

There are a few exceptions of course. Small blocks with very large bullets get cast at 650-660 degrees. A good example of this is the RCBS 35 250 in the RCBS 2 cav blocks, at 650 degrees the blocks get hot enough that I still need to slow down casting a bit or wait too long for the sprue to cool. Fairly large blocks in relation to very small bullets (22 cal bullets as an example) get cast at 720-730 degrees. In each case the tin is not oxidizing nearly as rapidly as it does past 750 degrees and it can still help with reducing Sb/Pb oxidation which tin does considerably less effectively past 750 degrees.

Crank up the heat! Pure nonesense! An old wives tale that it seems will never die.

Rick

[cbrick]

Great post Gear, ya beat me to it, you posted while I was typing.

Rick

[geargnasher]

Man I never knew pouring melted wheel weights into a 60 dollar mould could be so complicated. I might have to give this hobby up and take up something simple like brain surgery.

Pat, it isn't complicated. Keep the alloy within 20-30 degrees of 100F over full liquidus, preheat the mould or just start casting quickly until you get good fillout, then level out the pace to keep it there. Other tips include adjusting the stream/flow rate as necessary to assist fillout and the making of a sprue puddle, and/or adjust the pour technique (like swirl pour with a bottom-pour or contact pour with a ladle, or what ever gives you best results with each particular mould), adjust sprue puddle size to control sprue plate temperature for the sharpest boolit bases, and just have a ball!

Fussing with a pot temperature contol, stopping to look at every boolit when opening the mould and letting them sit in one side for and extra ten seconds (while the mould cools unevenly), and generally breaking up the routine so the mould fill/dump rate is all over the map is NOT the simple, effective way.

Gear

[cbrick]

Man I never knew pouring melted wheel weights into a 60 dollar mould could be so complicated. I might have to give this hobby up and take up something simple like brain surgery.

Gear is correct as ussual. Its not complicated, its simply applying a few simple rules that the metals industry follows and has written numerous papers on.

Tin begins loosing its ability to reduce oxidation in Pb/Sb alloys at around 750 degrees and past 750 tin itself oxidizes much more rapidly, the higher the temp past 750 the more this occurs.

This is how the metals industry deals with Pb/Sb/Sn alloys. They go further of course, adding specific metals to a melt at specific temps depending entirely on what metal they are adding and what metals are already in the melt. As bullet casters we have no need of that level of sophistication but there is still much we can learn about our alloys.

Look at it this way, the metals industry doesn't deal with Pb/Sb/Sn alloys this way simply because they have too much time and money on their hands. There is a legitimate reason for it.

Rick

[onondaga]

Thanks guys,

Sometimes I wish I had my old lecture material picturing Egyptian glyphs showing poorly filled-out jewelry castings followed by glyphs showing the jewelry caster being reduced to pieces of pet food with large crescent shaped stone blades because his mold was not hot enough. That was an absolute when Pharaoh's gold casting work was ruined.

Gary

[izzyjoe]

crank 'n up the heat seems to remind me of my hotrod'n days, everybody thought that you could just install a bigger carb or camshaft to get more H.P. it don't always work that way.

[onesonek]

I'll stand behind Gary's, Gear's, and Rick's advice. I'll throw lwkight's in there as well, even though he hasn't chimed in on this one. They have most helpful in correcting my technigue and methods, which solved all my inconsistanies.

[Roundnoser]

I will say that in my experience, it is a combination of both temperature (the pour, and the mold), the speed / force of the pour, the distance of the spout to the sprue plate, the cadence, etc. It all comes together to make good bullets. Not just temperature alone.

For my casting sessions, I get the melt up to 700 degrees. I pre-heat the mold (Lee 6 bangers), on top of the pot for about 30 - 45 minutes, and start casting. At first, the bullets are wrinkled. I set them aside along with the sprues (don't want to cool the pot by placing cooled lead back into it). Within 4 or 5 throws, my mold is up to temperature, and the bullets start looking good...good fill-out,etc. -- I keep a regular cadence, and watch the bullets. If they get too frosty, that tells me my cadence is too fast...cause the mold is too hot. If the bands / grooves start to loose that "sharpness", then I pick up the cadence a little cause the mold temp is too low. If the pour flow is too fast, I get little "fingers" that protrude out from the heal of the bullet (too much pressure in the lead flow will cause lead to seep between the top of the mold and the sprue plate)...so I slow down the pour. If the pour is too slow, I'll notice that the heal of the bullets (while still in the mold cavity), appear a hair smaller than the diameter of the mold...that means its time to increase the flow of the next pour.

I am constantly evalutating and correcting these little items. After awhile, it has become like second nature...don't think about it much while doing it.

[geargnasher]

Roundnoser, the best analogy I can think of for casting is driving a car. Remember the first time you got behind the wheel? It's a lot like that. After a few months your throttle foot gets trained to keep you going a constant speed up and down hill on the highway, you no longer have to think about downshifting when slowing or cornering, you know where to "look" when you look at the road ahead of you, and steering corrections and signal operation are completely automatic. Casting is a lot like that, lots to think about at first (particularly if you have a decent idea of just exactly what you SHOULD be paying attention to when casting in addition to basic safety), but after a while it's just autopilot while you think about something else.

Learning the correct habits right up front is important, that's why I hammer on it so much when a relatively inexperienced caster is asking for help. Good, basic, solid information is importantto casting good boolits, just as it is in reloading. It's really hard to UNlearn bad habits and practices when casting, trust me, I could write a book about doing it the WRONG way and having quite mediocre results.

Gear

[gee-gaw]

Gosh guys, I read a sticky on here a while back that helped me with my boolit fill-out, but seems contradictory too some of what has been said in some of the longer / more knowledgeable posters on this thread. Seems this caster was cooling his sprue by inverting the mould and touching it to a damp rag. This has increased my cadence considerably and allows me ( I think ) to keep my mould at a hotter temp so my boolits fill out better. Comments please. I want to know how to cast the best boolits that I can.
Oh, the pot is a Lee 20 LB bottom pour, and the alloy is WW with a couple of ingots of linotype thrown in to a near full pot. I try to cast as fast as I can, while glancing at the boolits that I drop to see if I need to let the mould cool or continue at the pace I'm going.
Thanks for the great info,
Wayne

[geargnasher]

crank 'n up the heat seems to remind me of my hotrod'n days, everybody thought that you could just install a bigger carb or camshaft to get more H.P. it don't always work that way.

That hits home! My excellent friend from college (Stephen, who I quote in my sig line) and I used to get great laughs going through Jeg's or Summit catalogs and seeing all the "bolt on" horsepower kits and then seeing the kids running the streets with such stuff. Take a worn-out, bathtub-head 350 Chevy in an '84 pickup with smog pump and 1-3/4" single exhaust and bolt an 850 Holley on top with a single plane intake and a rumpety cam and wonder why it keeps breaking the stock rocker arms and valve springs, and won't get out of it's own way. But they thought they were cool. My cobbled-together '46 Chevy pickup with a stock crate 350, iron intake, 600 Q-jet and some long-tube headers would take them to the cleaners.

Gear

[geargnasher]

Gosh guys, I read a sticky on here a while back that helped me with my boolit fill-out, but seems contradictory too some of what has been said in some of the longer / more knowledgeable posters on this thread. Seems this caster was cooling his sprue by inverting the mould and touching it to a damp rag. This has increased my cadence considerably and allows me ( I think ) to keep my mould at a hotter temp so my boolits fill out better. Comments please. I want to know how to cast the best boolits that I can.
Oh, the pot is a Lee 20 LB bottom pour, and the alloy is WW with a couple of ingots of linotype thrown in to a near full pot. I try to cast as fast as I can, while glancing at the boolits that I drop to see if I need to let the mould cool or continue at the pace I'm going.
Thanks for the great info,
Wayne

Not contradictory at all to what Gary, Rick and I have been saying here. BruceB's speed casting method (I'm assuming that's the sticky to which you refer) is a way of maintaining the mould at proper temperature for casting the best boolits, but while upping the pace considerably.

As I remember, Bruce's method is mostly targeted at six-banger Lee moulds which have a fairly thick aluminum sprue plate that has a tendency to overheat when you crank the pace up. You have two choices: Slow the pace until the natural air-cooling effect is enough to keep from smearing molten bases, or do a quick quench on a wet towel or sponge in a pan of water to knock just a few degrees off the the sprue metal and plate each cast. That shortens the cool time, and in fact you can cast about five pours a minute or more doing that for extended periods of time, which will yield about 1800 boolits an hour if you can keep your pot fed from another bottom-pour pot mounted above it to premelt your ingots.

If you run your alloy as cool as possible, it imparts less heat to the mould and sprue plate, and will allow you to cast even faster. During a long production session with pistol boolits, I often run the alloy on the "-30" side of 100-over-full-liquidus, that keeps the mould from overheating at four pours a minute in most cases.

Many times I'm not in a hurry, and am casting for top quality, so I either carefully bottom-pour with a bit hotter alloy, and take my time, or ladle cast, which is an excercise in slow-and-steady in itself.

What ever you do, consistency of pace and method is critical to consistent boolits.

Gear

[ColColt]

I was going to bed 30 minutes ago but got intrigued with this and had to read it all. I started casting back in 1972 and have just recently discovered I didn't know anything all that time. I thought I did, I read the Lyman books and others, got my Model 61 Lyman pot, had plenty of lead and Linotype and a couple of molds. I had no one holding my hand as I was the only one I knew that attempted casting. Everyone of my shooting cohorts shot jacketed.

In the past few months I've learned more and still am obviously, than I did the preceding decades of casting away, oblivious to hardness levels, what size boolits a given mold would drop or what to do about it if it wasn't enough. I thought if a boolit was giving wrinkles, voids, soft bands...crank the heat up to get better fill out. Nearly everything I did, looking back, was wrong. I knew nothing of alloys other than lead and Linotype and for sure had never heard of Kroil oil in a mold or using sawdust as a flux. I stand indebted to those, not only in this thread alone, but in so many other threads started by myself and others for the knowledge and understanding of how wrong in so many ways I was-not that I've achieved perfection as this thread would never have been started if that were the case.

I'm going to mull this over again tomorrow and then again until it sinks in. One thing...


Fussing with a pot temperature contol, stopping to look at every boolit when opening the mould and letting them sit in one side for and extra ten seconds (while the mould cools unevenly), and generally breaking up the routine so the mould fill/dump rate is all over the map is NOT the simple, effective way.


This hit home as it precisely describes my usual casting session. After dropping about 5 or ten boolits, I look them over, raking them with my hammer handle I use to cut the sprue while waiting for the sprue to harden. Many times I'd get my large spoon and pick up several that look bad and put them back into the pot. I've managed to get some good looking boolits but I suppose the alloy gods took pity on me many times.Yep, got a ways to go yet it seems.

[Reloader06]

ColColt

You are in a large group here. The main difference is you ARE willing to listen and learn. I am working on it.:veryconfu

Matt

[cbrick]

Nearly everything I did, looking back, was wrong.

No, not wrong. You were doing the best you could with the information available. I can assure you that Gear, myself and every other knowledgable caster that posts here started out casting exactly as you did.

You, just like most of us here are willing to try to learn and question whether or not it is better.

Keep reading, keep learning. Are your bullets better today? Was it easier and/or faster to get better bullets? Do you feel more confident in how you go about casting now? You weren't wrong before and your certainly not wrong now being curious and willing to test things that are new to you. That's how we all learned.

Rick

[bpratl]

I have learned more from this Forum than any other. I am extremely pleased that everyone is more than willing to share their good and bad experiences. Thanks to all for sharing as I am grateful, learning and having a lot of fun.

[garbear]

Gary and gear post have helped me a ton. I have learned crank up the heat wasn't necessary. I cast at abut 650-675 and get good fill out. Once I started applying the technis, I started getting much better results.

Garbear

[Doby45]

I cast at 650-675 and get great boolits with BORING regularity.

[Char-Gar]

Antimony is a very interesting alloy and Linotype is rich in it for a good reason. Antimony is a metal which contracts when hot and expands when cool, opposite from lead and most other metals. This characteristic made it perfect for type metal that needs to give very sharp edged castings of small letters.

Antimony will do the same thing for bullets. The only downside is expense and the antimony crystals are very abrasive to the barrel metal compared to lead and tin.

[onesonek]

Gary and gear post have helped me a ton. I have learned crank up the heat wasn't necessary. I cast at abut 650-675 and get good fill out. Once I started applying the technis, I started getting much better results.

Garbear

Same here,,,one of the best tips Gear gave me, was to leave the thermometer in the melt and let it cool down. Then turn it back on, and watch for when it turns full liquidous. Knowing where I was at with that, and staying in his recommended zone and cadence, helped alot with my quality/consistancy. That along with swirl casting part!
Then too, I found the amount of oxidation/dross, and need to flux or reduce it back in, decreased substantially as well. The only time I have had to go beyond that 100 degree over liquidous mark, is with one alloy I'm playing with, has .05% Cu. in it. But still only 25-30 degrees over the 100 mark, and still under 750. Otherwise with the one alloy I use most, I run right close to the 100, due to my inexperience, cadence, and brass mold. I can likely lower that, once I get a little better at "driving the car"
I found that to be a great analogy. And while I stated earlier, it has helped greatly with all my inconsistencies, I still have room for improvement. I'm still pretty green to all this!!

[ColColt]

I've been chomping at the bits to cast some more today but it's pouring rain, thunder, etc and I have to keep the garage door open to vent so, it may not happen today unless it lets up. Last night I lapped this mold with JB Cleaning Compound since nowhere around here seems to have any Clover. I then followed with some Mother's Mag and Aluminum Polish, washed with Joy and water and it's read to go. I had trouble with the right side of the mold dropping the boolits so figured lapping was in order.

This is a shot of what I was talking about earlier about half of the boolit would be frosty and the other side shinny. Hopefully, I've gleaned enough info here to eliminate that next time.

I know the day will come when I have to buy more Linotype but have enough now to last awhile-especially if mixed with certain amounts of lead. I've only cast using straight Linotype once or twice and that was years ago-didn't like it so I went back to the 50/50 mix later. I use lead/LT a lot because good ww's are like hen's teeth around here and I only have about 50-60 pounds of it and most of that was from Kathie. I wish the made a thermometer that was about eight inches long and would still measure temperature precisely even if you only have an inch left in your pot. I may need to take a trip to Fantasy Island for one of those.

http://i180.photobucket.com/albums/x220/ColColt/Misc%20Stuff/_DEF4039a.jpg

[onesonek]

Gary and gear post have helped me a ton. I have learned crank up the heat wasn't necessary. I cast at abut 650-675 and get good fill out. Once I started applying the technis, I started getting much better results.

Garbear

Same here,,,one of the best tips Gear gave me, was to leave the thermometer in the melt and let it cool down. Then turn it back on, and watch for when it turns full liquidous. Knowing where I was at with that, and staying in his recommended zone and cadence, helped alot with my quality/consistency. That along with swirl casting part!
Then too, I found the amount of oxidation/dross, and need to flux or reduce it back in, decreased substantially as well. The only time I have had to go beyond that 100 degree over liquidous mark, is with one alloy I'm playing with, has .05% Cu. in it. But still only 25-30 degrees over the 100 mark, and still under 750. Otherwise with the one alloy I use most, I run right close to the 100, due to my inexperience, cadence, and brass mold. I can likely lower that, once I get a little better at "driving the car"
I found that to be a great analogy. And while I stated earlier, it has helped greatly with all my inconsistencies, I still have room for improvement. I'm still pretty green to all this!!

[ColColt]

And while I stated earlier, it has helped greatly with all my inconsistencies, I still have room for improvement. I'm still pretty green to all this!!

What bothers me about this is that I started way back around 1972. I should know all there is to know about casting with that many years. However, the main part of my casting was probably from 1972-1976 and then the job, photo hobby, regular reloading, etc. got me away from spending much if any time casting. I picked it up again for a year or so around 1980 and then got away from it yet again for a variety of reason. So, all in all, I don't have 38+ years experience had I continued at least once a month or so making boolits. You forget a lot over time and still continue with bad habits if no one corrects you. I had no "teacher" to say, "Hey, that's not the way you do it". It was all trial and error as I mentioned before, no one I knew who reloaded did any casting back then. I've only recently started once more and while I remember the basics of safety and casting in general, there were finer points I didn't know until I came here. This forum is to casting as Ben Casey and Dr. Zorba were to Neurosurgery. You've got to be old to remember those guys.:smile:

[onondaga]

Thanks for posting the picture. That is a good boolit. You have a minor hot spot showing in that porosity on the surface is visible mostly to the left and right of the mold parting line and in the center from top to bottom.

That is generally caused by some minor turbulence in your pour concentrating the heat in that affected area. To get an over all finish that is the same on the whole bullet takes an extremely even heated mold. The last place that cools gets the most porosity and you can see where it is in the porosity or frost pattern zone that was the hottest part of the mold and the last part of the boolit surface to cool.

I wouldn't jump through hoops to perfect that boolit any more, it is fine. Swirl casting would help even out the finish but that is pretty consistent with what you show and would not effect accuracy. I like an overall satiny finish because they look prettiest when tumble lubed but it wouldn't shoot any better than what you have there.

Gary

[geargnasher]

ColColt, as Rick said a few posts back, we all had to crawl before we learned to walk, and while I did have the benefit of an experienced mentor for my first couple of sessions, once I was off on my own there was so much I didn't catch that wasn't explained to me outright that I struggled pretty hard. I really wish I had had a resource such as this site, would have saved me a ton of trouble and frustrations. For one thing, it took me years to realize that smoking a Lee mould is just a sorry excuse for not soaking out the cutting oil from the cavities before the first session with a new one. That came from a tidbit from a college elective course I took in metal casting non-ferrous metals.

So don't feel bad, just try to keep an open mind and a positive attitude, you're really about to get the hang of it, I can tell by your castings already you are doing a lot of things right.

Now, you don't realize it, but if it's raining right now you are missing an absolutely golden oppertunity to cast boolits today! As Felix describes it, a "condensing atmosphere" is pure magic when casting, I don't know why. It doesn't seem to be the temp or humidity that makes it so nice, something about dewpoint does. If you haven't cast boolits when it's raining with some exposure to the rainy air, you don't know what you're missing! Get out there and pour some!

As to the "half frosty, half shiny" boolit you posted a pic of, it is a PERFECT example of being between the steps of the two ideal temperature ranges. The mould is a little bit too hot in places for shiny boolits, and too cool in other places for the light frost. When I get boolits like that, I know it's time to keep casting a few more quickly to get the mould temp evened-out and up to where the whole thing is frosty. Many other folks choose to slow down a bit because they like theirs shiny all over. I choose to go frosty because I find it much easier to get good fillout, my production is higher, and I don't have to look as close to see if I'm creeping up on the edge of frosty when I don't want to be there. Your mould temp will even out throughout the blocks as you maintain a constant pace and don't let the blocks spend any time being open then absolutely necessary. If you need to slow down to cool it, do so with the blocks and sprue plate closed, or cut the sprue and let the boolit cool in the blocks for a few more seconds before dumping, this will keep all parts of the cavity at a constant temp. When you open the blocks, air currents cool the parts that stick out the most, and this can cause fillout problems. Basically your mould temp in the pic was "on the fence", my recommendation is to go both ways, go for slight frost, then really frosty (too hot), and slow down your pace until you start getting half and half again, then keep slowing down (don't just stop and wait) until the mould is casting filled-out, shiny boolits. If you let it cool any more, you will start having fillout problems and wrinkles.

Here's an example of too hot mould (left), just right (to me, others prefer shiny), and mould too cool (right). Alloy was WW + a pinch of tin, temp about 125 over full liquidus because it's a heavy brass mould and it really sucks up the heat:

http://castboolits.gunloads.com/attachment.php?attachmentid=28007&d=1293562439

Gear

[Billwnr]

[QUOTE=geargnasher;1307418]Good grief, where did all you "crank up the pot temp" peope come from? Are you really trying to help this man or confuse him so much that he'll never get it right? I'm sure you folks are getting the results you desire from your methods or you wouldn't recommend them, but I disagree very strongly with all of you,
POT temperature should be maintained somewhere in the neighborhood of 100 degrees F over the FULL liquidus point of the alloy, because excessive heat destroys the oxygen-shielding effects of tin in the mix, and that's the whole reason tin is there in most cases (exceptions being binary lead/tin alloy, where the tin also adds a measure of strength to the lead). With pure lead, you can run it as hot as you want, an often need to go 200 or more degrees above 621 to get moulds to fill well, but there are no other alloys to oxidize out or to ruin in the process, so feel free to crank it up.



I come mostly from the CBA forum site and shoot in the matches. The normal process is to cast up the next years worth of competition bullets over the winter when it's lots cooler than doing it on a 90 degree summer day.

The first winter I produced bullets I ended up with 1655 good bullets for the next years shooting. It took approximately 160 hours worth of effort. I had zillions (over statement) of rejected bullets, actually it was approximately 70% of production. The reasons for rejection were too low of a casting temperature, mould issues, alloy cleanliness and a few others. Towards the end of the casting season the acceptance rate greatly increased. The primary reason was cranking up the pot temperature.

The 2nd year I produced approximately 1200 match bullets in 40 hours of effort. Again, the reason for wayyyy higher acceptance rate was higher pot temperature. I've used thermometers on the Lyman and RCBS pots and the max temps come in around 750-770 degrees.

Usually the proof is in the pudding. I've shot down to .525" 5 shot groups at 200 yards, a couple of ones around .303" 5 shot groups at 100 and a couple of national records in the military rifle competition.

I'm more interested in flinging shots downrange than I am in discussing the details of what it takes to make a perfect pot temp; alloy composition/cleanliness; mould preparation; and other little details (no offense to those that do. it's just not my thing)

All I need to know is you need a constant alloy composition (as constant as wheelweights and linotype are which is the subject of a different discussion), a high pot temperature, a clean mould with adequate vent lines, good mould temps and an eye for inspecting your bullets.

If your interest is small groups on paper, then the inspection details are key. If it's hunting or plinking... lots of bullets the first shooter would reject are acceptable.

just my opinion and not meant to start any arguments.

[geargnasher]

One more thing, ColColt, I have noticed that you tend to have an "absolute mind" like I do, which can get you into trouble with this hobby. Once you learn what works best for you with this mould, don't write it in stone because you might have to do something a little different next session even with the same mould and alloy. Weather, and the mood of the casting gods are the only explanations I have, but you have to remain flexible with your technique, pace, and to a certain degree pot setting. The next mould you pick up, or next alloy you try will be different, so try to focus on ways to establish pace and technique for each session, as each session tends to be unique.

Some advice I've given others that seems to work for them:

First, turn on the pot and get your alloy melted, flux with sawdust, let it smolder, strir the top half of the melt and the sides with a stick, scrape the bottoma and sides and skim with a spoon. If you have a hot plate and have made a mould oven, be prepping and preheating your mould as well. If you don't know exactly what your alloy is, or if it's a new mix, stick your thermometer in it and turn off the pot. Watch the temp and periodically stir the melt with your spoon, lifting up a spoonfull and letting it pour back into the melt. The INSTANT you start to detect solid grains forming in it (like small bits of sand), note the temperature. Turn the pot back on and note when the melt is fully liquid again (two or three more degrees should do it). That is your full liquidus temperature. Leave it on an let the temp go another 100 degrees or so and do what you a have to to keep it there for starters. Sometimes you need more heat, sometimes less, stay flexible, but it's a good place to start. If you preheated your mould, start casting, noting the sprue cool time (4-6 seconds is about right in my book), note how the sprue puddle is flowing to see if you need to pour more lead to get it hotter, or less to cool it some. Throw down about ten pours and take a quick glance at the boolits. Even if you preheat, it takes some time and a consistent pace for the temp to even-out. Gary's "Swirl Pour" technique indeed is very effective for almost all boolit moulds and alloys, so go ahead and do that from the start if using a bottom-pour pot. It really helps even the heat and purge air. Once you get going, all you have to do is keep an eye on pot temperature to make sure it's staying where you want it, adjust pour stream volume as necessary, adjust sprue puddle size, and gradually adjust casting pace to keep the mould temperature "in the zone". I find that taking and noting mould block temperature is really not necessary, your boolit surface "finish" and fillout will tell you whether it's too hot, too cold, just right, or uneven. Pot temperature IS important, and is best measured somehow because your are maintaining the alloy (a molten pot of metal is a VERY dymamic thing that needs a good enviroment to be as stable as possible), and those who don't pay attention to that fact and "dink" with the settings from time to time to maintain a consistent, stable pot of metal are going to have inconsistencies throughout a session. Many people cast without a thermometer, but it's so stupid-easy to get a good one and take all the mystery out of it, no need to struggle with another unknown quantity while casting.

That should work for any mould, and most common boolit alloys: Find full liquidus, go 100 over, get the mould hot somehow, start casting rapidly and read the signs of boolit fillout/finish and sprue cooling times until you settle into a happy pace.

Like the throttle, brake, and steering wheel, your casting pace, timing of sprue cut, size of puddle, and fill technique are the "controls" you use while driving your mould through a session. Your pot thermometer is your rearview mirror, look at it regularly but not constantly to get the whole perspective on what you're doing. Oh, and NEVER stop in the middle of the highway! A pause of even 30 seconds in the middle of a session will allow your mould to cool enough to make the next few pours bad ones, so if you do need to pause to adjust something like your pour rate or loose sprue plate, try to keep the cavities full, just cut the sprue and don't open the blocks, this will conserve heat. Then cast the next two or three pours really quickly to catch back up, throw them in the cull pile regardless of appearance and then resume the previous pace.

Gear

[geargnasher]

Bill, I sure don't see any of this as an argument, and I'm glad you don't. I do feel compelled to give some constructive criticizm to your technique, and point out that you have drawn some very wrong conclusions from your experiences. Please listen and consider what I'm about to say, and next winter I hope you give it a try, I guarantee you will find that what I recommend will work better and your reject rate will be about nil.

I don't know why so many people want to discount the things I say about this, it's clearly stated in a half-dozen popular manuals, there is nothing new under the sun.

Gear



I come mostly from the CBA forum site and shoot in the matches. The normal process is to cast up the next years worth of competition bullets over the winter when it's lots cooler than doing it on a 90 degree summer day. It's very good to cast all your competition boolits from the same batch of alloy, and in the same session, one more variable reduced as much as possible.

The first winter I produced bullets I ended up with 1655 good bullets for the next years shooting. It took approximately 160 hours worth of effort. I had zillions (over statement) of rejected bullets, actually it was approximately 70% of production. The reasons for rejection were too low of a casting temperature, mould issues, alloy cleanliness and a few others. Here's where I start to think you drawing the wrong conclusions. Towards the end of the casting season the acceptance rate greatly increased. The primary reason was cranking up the pot temperature. Sorry, wrong answer. The correct conclusion to draw was that your mould finally got hot enough, because you were casting too slow and it didn't start to fill out until you were pouring an unecessarily overheated alloy into it, which as a by-product finally got the mould up to the temperature it liked. What would have given your far better results from the outset would have been lower the pot temp about a hundred and fifty degress, and get your butt in gear and cast a minimum of something like three pours a minute to keep the mould hot. Your alloy won't dross as badly, the composition will remain constant throughout the session because you won't be drossing-out tin and antimony, the cooling rate of the boolits will be consistent leading to more consistent final hardness, your production rate will be vastly increased, and your reject rate will be MUCH lower.

The 2nd year I produced approximately 1200 match bullets in 40 hours of effort. Again, the reason for wayyyy higher acceptance rate was higher pot temperature. Again, this is a false conclusion. Mould temperature determines boolit quality, casting too slow and compensating with an overheated alloy is bad for the alloy and is merely a band-aid for the real problem, which is that your cycle of putting molten metal in the mould wasn't fast enough to keep the mould up to temperature with anything less than an overheated alloy. I've used thermometers on the Lyman and RCBS pots and the max temps come in around 750-770 degrees. Like Rick said earlier, you must REALLY hate tin, because you're rendering it totally useless as a fillout aid by going over 750, no wonder you have so many rejects.

Usually the proof is in the pudding. I've shot down to .525" 5 shot groups at 200 yards, a couple of ones around .303" 5 shot groups at 100 and a couple of national records in the military rifle competition. Yes, but at what cost? Time and frustration are costly. If you follow a few simple guidelines based on sound scientific priciples of the properites of the metals and tools with which you're working, the results will be superior and predictable.

I'm more interested in flinging shots downrange than I am in discussing the details of what it takes to make a perfect pot temp; alloy composition/cleanliness; mould preparation; and other little details (no offense to those that do. it's just not my thing) But spending 140 hours for 1655 match boolits IS? I fail to understand your logic. It is not complicated. You've just been going about it the wrong way, because you don't have a complete understanding of the few, simple factors that govern boolit quality and how to manipulate them to your advantage.

All I need to know is you need a constant alloy composition (as constant as wheelweights and linotype are which is the subject of a different discussion), a high pot temperature, a clean mould with adequate vent lines, good mould temps and an eye for inspecting your bullets. Almost. You need to know what temperature is BEST for the alloy, just like what incubator temp is best for chicks, how to properly flux/reduce it, and the rest is up to your techniques of pouring and the pace needed to maintain the mould temperature in its happy place.

If your interest is small groups on paper, then the inspection details are key. If it's hunting or plinking... lots of bullets the first shooter would reject are acceptable. Here's one big problem with casting a huge pile with sloppy technique and just picking the few lottery winners out of the batch: It's very difficult to detect internal flaws, and slight differences in boolit temper from one to the next due to variances in mould temperature are impossible to see, as well as variances in alloy composition over the course of a long session with the same pot of metal due to drossing from the overheating, and finally there are slight differences in size of the nose and bands throughout a long, overheated-alloy session which can matter downrange. Sure, you can cull most of this out with a lense, mic, and scale, but your rejection rate shouldn't be nearly so high for the amount of effort you put into it.

just my opinion and not meant to start any arguments.

[ColColt]

It got the best of me and I decided to fire up the pot. I let the inch of alloy I had in the pot start too melt and had my mold on the burner which is unfortunately the coil kind but, it's all Walgreen's had at the moment. I turned up the thermostat to about 8 on the Lyman to get things going and added six ingots of 50/50. Once the temp got to about 675 I tried to keep it there or a tad lower and added about a tablespoon of sawdust, let it burn down and stirred. To make a potentially long story short, I tried to keep in mind Gary's instructions about letting the alloy swirl and I had to also raise the mold guide a little higher. It took a while to get the hand of tilting the mold and letting the stream hit a little off center since, well, you know how old habits are hard to break.

My first 25 or so still had the frosty look on one side and the base of the boolit but I think primarily why that happened I had the mold pre-heating on the burner and while I was waiting for the alloy to get up to temp, I started moving the mold around so it would get even distribution of heat-on it's bottom for awhile, then on the sprue side and then straight up. I think I let it linger on the sprue side too long and that may have been what caused the bottom of the boolits to be frosty-too hot in spots and not all over the same. I'll know next time.

As I progressed and had already about 75 knocked out I noticed the frosty look had pretty much went away from the bottom and sides. I'm sure this was due to the mold now being better heated all over rather than in spots. This is just a guess as to why the base was frosty early on. Here are a few pics. The first one is after I got started good. You can see the ones I segregated at the top left. The second one was those close up and you can see the frosty look I spike of. Oddly enough, these weighed about 2-3 grains less than the others for whatever the reason. The last one was after the mold cooled down from creating those hot spots and they began to look like that all over.

If ya'll don't mind, I'm going to copy a lot of this info and print it out so I can refer to it when needed rather than come back to the computer from time to time...it's apples of gold.

http://i180.photobucket.com/albums/x220/ColColt/Misc%20Stuff/_DEF4042a.jpg

http://i180.photobucket.com/albums/x220/ColColt/Misc%20Stuff/_DEF4043a.jpg

http://i180.photobucket.com/albums/x220/ColColt/Misc%20Stuff/_DEF4044a.jpg

[cbrick]

Last picture is downright nice ColColt, by golly I think you've begun picking up some good casting habits.

I never place the mold directly on the heating element of the hot plate. I have a 1/2 inch aluminum plate (thought it was 5/16 but its 1/2") on the hot plate and put the mold on that. This could well be the cause of uneven heating. The aluminum will distribute the heat far more evenly than will the heating coils. I also drilled a hole in the aluminum plate to hold the temp probe of Swede Nelson's (NOE) digital thermometer so that I know what temp I'm getting the mold to. Curious minds just need to know.

In your center picture, the bullet on the far left has what I call a heat shrinkage. Don't know if that's the correct terminology but that's what I call it. It's caused by an uneven heating of the mold. It is most times the first sign of the mold getting too hot I'll get when everything has been going well and then I get to casting a bit too fast. I don't stop casting, just slow down for a few pours and it returns to normal. Inside a lube groove is where I almost always see this first.

Center picture, bullets in forefront appears the sprue was indeed too hot. Did you place the mold on the hot plate upside down (sprue down) just before beginning casting?

Rick

[ColColt]

Center picture, bullets in forefront appears the sprue was indeed too hot. Did you place the mold on the hot plate upside down (sprue down) just before beginning casting?

I did. In fact, I turned it various ways before casting...sometimes up, sometimes down to distribute the heat better-I thought. I feel sure now it was the mold getting too hot in places by doing this. I'll have to find a better way. I don't think I have anything aluminum around here 1/4-1/2" thick but will look.

[cbrick]

I picked up my square piece of 1/2 inch aluminum (its just slightly larger than the burner on the hot plate) at a metals supply place. When they do large commercial cutting jobs they have cut ends and put these in a bin, these are usually sold by the pound. Picked up my piece for a couple of bucks.

Rick

[geargnasher]

I think you're getting the hang of it now, ColColt. Your alloy has plenty of antimony and tin, so it tends to cast boolits in the shiny (cooler mould) temp range better than straight wheel weights does. I usually use WW plus 1% or so tin or 50/50 WW/pure, so that's why I like a little frost.

If you had gotten your mould hotter, the entire boolit would be frosty all over, and smaller, and lighter than the shiny ones. When you're seeing frost, do what Rick said and just slow down the pace a tad, pour a smaller sprue puddle for a while, and the frosty spots will go away.

If you use lower-antimony alloys, you might find you need to get the mould hot enough to get a full, even, LIGHT satin frost for the best fillout. Maybe casting good boolits from a cooler, shiny-boolit-producing mould comes more natural to you than it does to me. It all depends, just listen to what the mould tells you!

Gear

[ColColt]

To make matters easier, I ordered one sans the exposed coil from Amazon-1000 watts. That should do it. I probably should have done that in the first place.

Many thanks to those who took the time to share your knowledge on this and for your time spent relating it. It was well received and I will put it into practice. Old dogs can learn new tricks, I've discovered, and not above being shown the error of my ways. One question-where were you guys in 1972 when I started all this?:)

[Billwnr]

geargnasher, My casting "session" was measured in weeks, not just one day. Not one week not two weeks, but probably a span of 7 to 10 weeks. The 4 cavity mould gets up to temp in about 10 pours and after that is so hot that eventually a damp sponge is needed to keep the lower the mould temp.

There are a few tips you and others could pick up from competitive shooters interested in high quality bullets. High quality is defined as all bullets of equal quality. Some of us go as far to weight sort them. It does pay great dividends where four 5 shot groups at 100 yards will have an aggregate of less than half an inch.

[geargnasher]

Bill, I weigh and sort everything that really counts. Not saying the methods I recommend preclude that. Nor am I the best boolit caster on the planet, not by a long shot. I'm saying that you might benefit from a re-evaluation of your knowledge of the properities of boolit metal and how to work with with it more effectively.

ColColt, my pleasure, glad to help. My parents were married in 1970, I didn't come along until five years later, sorry you had to wait so long! Now I can't tell you where the others were...

Gear

[MikeS]

Ok, I have a question. What would cause frosting only on the top of the mould (base of the boolit)? I have run into this a few times where the nose is nice and shiny (and well filled out) and the base is frosty (not extremely but it is very noticeable!) I've been trying to keep my pot at around 650 or so, although now I'm not real sure, as my digital thermometer is acting strange, the last time I was casting, it was reading around 450, yet the pot was way hotter than that, and I was casting as normal even tho the thermometer was showing such a low temp. I'm using a Lee 4-20 pot, and normally keep the dial set between 3 and 4. Could my thermometer need a new battery even tho the low battery light isn't on? Thanks for any thoughts on these issues!

[cbrick]

Sprue plate too hot as in the photo above by ColColt in post 47, center photo. Don't stop casting, just slow up a bit. I control this with a gentle air flow from a fan. If the mold is starting to get too hot I hold the bottom of the mold towards the fan, if the sprue plate is getting too hot I hold the sprue towards the fan.

The fan doesn't need to be a hurricane, just gentle air flow to keep the air moving, this can cool a mold fairly quickly. Doesn't take long to get the hang of it and how little it takes to work.

Rick

[onondaga]

Rick's suggestion is good, you can also try a smaller puddle size with your pour if the sprue plate is getting too hot and causing excess frosting of the boolit base area. A wet sponge or towel will cool the plate real fast too. A simple thing like leaving the plate open for a few more seconds before closing to make the next pour could even take care of that.

Gary

[geargnasher]

+1, smaller puddle, or use Dale53's trick of a small manicurist's fan to cool the top of the sprue and plate a bit right after each pour. Smaller puddle usually is all I ever need.

Gear

[MikeS]

Thanks! I will try a small fan, I think I have one that will fill the bill perfectly. On my thermometer, it's rated to I think either 1200 or 1300 degrees intermittent, and 750 continuous, could I have overloaded it? If so is it toast now, or will it come back? It's made by a company called Atkins Technical and I think they're out of biz as I couldn't find them on the web. The sensor is hardwired into it, so if it's just the sensor that's bad I could possibly have a friend that's more electronically talented than I am replace it for me.

[ColColt]

ColColt, my pleasure, glad to help. My parents were married in 1970, I didn't come along until five years later, sorry you had to wait so long! Now I can't tell you where the others were...

Let's see-when I was 36...well, let's forget that. You've done well, Grasshopper.:)

I have an eight inch fan I keep about twelve feet away to help ventilate while casting. With the garage door open on one bay I have it trained to blow toward the door but not directly over the pot. That's a good idea about cooling whatever part of the mold that may be giving hot spots and all I have to do is side step a few feet close to where the fan is.

[cbrick]

That's a good idea about cooling whatever part of the mold that may be giving hot spots and all I have to do is side step a few feet close to where the fan is.

Hhmmm . . . Side stepping, not exactly how I go about it.

I have a small fan with about a 4 inch diameter blade that is set to blow right where I open the mold and drop bullets. It is also placed just far enough away that it is just a gentle flow of air where I dump the bullets. If I notice the sprue may be getting a bit too hot I hold it towards the fan for just a couple of seconds, Not trying to get a cool sprue, simply keep the heat in it from rising.

I preheat the mold and start casting with the fan turned off. With a pre-heated mold and 3-5 pours or so the mold is at proper temp and then I turn on the fan to keep it at the proper temp. The number of pours before turning on the fan will vary, in the winter with a cold shop it may be 20-30 pours before the fan is needed, in the summer in a hot shop it will be much sooner.

The whole point of the fan is to keep a properly heated mold properly heated with a gentle flow of air. If the sprue or the bottom of the mold need cooling just hold it in the air for a tick longer.

As a side note, if your casting HP do this with the cavities closed, bullets in the cavities and the pin in the blocks. If your using the Cramer HP system keep the blocks closed, never leave the pins in this flow of air, they will cool very rapidly. HP pins have very little mass to hold heat and get too cool very fast.

Rick

[ColColt]

This is just a follow up on all the excellent advice I was given. the other day I received a 44 cal mold from Dan of Mountain Molds and was able to give it a try today and what I had gleaned from this thread.

I was most happy with not only the mold as it dropped the boolits without having to tap on the handle pivot hardly at all. Early on(first 50 or so) all I had to do was to open the handles and they dropped out. It was only after that or more I'd had to tap a time or two-no big thing to me as perhaps the mold had gotten hotter. I put to use the method of letting the melt swirl and tilted the mold maybe 10 degrees or so left and then right(two cavity mold) and voila-no hot spots. I kept the melt at approximately 650-675 most all the way though and all in all I couldn't have asked for a better casting session. I did apply Bull Plate early on which helped as all know.

Hat's off and kudos to Dan and all those that gave such marvelous advice in this thread. Of all the forums related to guns I've been to I classify as roses-this one is an orchid.

http://i180.photobucket.com/albums/x220/ColColt/Misc%20Stuff/_DEF4046.jpg

[gray wolf]

Rick -- Gary-- and-- Gear

Way good advise, I use it and it works. I have cast for hours with a pot temp of 625*-650*
And only had to adjust was my casting speed and the size of the sprue puddle.
I think all they have written will help anyone that is willing to listen.


Sam

[Whistler]

I tried the advise posted in this thread on today's casting session. I was casting .429 208gn wadcutters from an aluminum mold and had very little success. I tried swirl pouring and cast as fast as I could, but could not get proper fillout. I tried temperatures from 650 up to 900 degrees, and it was first at 850 that I was starting to get acceptable fillout. At 900 most boolits were perfect and every third to fourth fill I cooled the sprue plate on a wet sponge which gave me nice sprue cuts.

[onondaga]

I wish I could watch you work and bring my own thermometer. I don't know of a pot that will heat to 900 in any models mentioned on this board except gas fired.

Bullet alloy poured at 900 is beyond any extreme I have ever read about. My setup beyond 775 will not cast anything even resembling a boolit unless I am casting pure lead. I have cadence of about 3.75 drops a minute and rarely need to adjust up or down from that. That 900 degree temperature may have oxidized off everything but pure lead and you are casting pure lead.

Pure lead at 900 degrees cast into a room temperature mold will work reasonably well. Any boolit alloy cast at that temperature of 900 in a warmed mold gives me images of a hot liquid sprue puddle for a long long time and white raisin looking things in a bowl made with fried boolit alloy.

Your method doesn't jive to me at all unless you don't use a thermometer and your dial setting is #9 and really much less than 900 degrees . 900 degrees even makes aluminum of the mold warp and get difficult to align and very sticky to itself and any boolit alloy, let alone the lightening fast oxidizing of the Tin in the molten alloy at 900 and exposure to air. Aluminum itself noticeably oxidizes at 900 degrees. Physical properties of alloys, thermodynamics of casting and experience instructing casting just won't allow me to believe what you have written. I question your motive.

Gary

[geargnasher]

I'll never understand people who do everything they can to discredit the long-established and proven facts of chemistry and physics. I'd like to be there too, any time anyone tells me they don't get good fillout until the pot is at 800 or 900 degrees, because there is something going on that isn't being translated to the posts.

Gear

[cbrick]

There are people that find it humorus to try and mess up the efforts of new casters and people that are trying to learn.

If there weren't people like that explain computer virus's. Those that spread them can gain nothing by doing so except a warped mind telling them they crashed someone elses computer and that's really funny.

Rick

[Whistler]

I've got the NOE Lead Pot Thermometer, it sits at the left edge of my Lee Pro Pot IV. I have left it inside when the melt solidified and watched it as the melt goes into a total liquified state around 650 degrees indicated from the thermometer. When cranked up to max (9), the Lee pot takes about ten minutes to reach 880-900 degrees. Outside temperature was about 80 degrees.

From my estimation, this leaves the thermometer showing about 50-60 degrees too high. So my previously stated 900 degrees would be about 850. I have no dross on my melt, the sawdust on top is just sawdust.

geargnasher: If you believe me to actively discredit any of the fact presented in this thread, from you or anyone else, then you are mistaken and I apologize if I have given that impression. I am not a chemist, I am just an amateur boolit caster and hobbyist trying to remove the sources of error that I myself and apparently others suffer from. If we together, as you wrote, can translate those errors into these posts, then we have all gained valuable knowledge, even you experienced casters who do get right fillout without extreme temperatures.

[Echo]

WW's in themselves don't have any tin that I know of. That's why I added about 3% but this alloy contains no antimony. Linotype had approximately 4% I believe but also has 12% or so of antimony and I attributed that to better fill out of the bands since WW's + 3% tin has none.

Well - 3oz of tin into 160 oz of WW's is closer to 2% tin. And WW's are said to have 4% antimony.

I adjust the bar on the Lee 4-20 pot so that the mold is about 1/2"-5/8# away from the spout and that seems to work pretty good. The amount of boolits per minute is about the same with all alloys so, I don't think speed was a part of the quotient as for this problem. It's sort of odd in that one side of the top band may have been sharp but the other side wasn't...weird. I did get some respectable boolits after about 20 or so but still not as well defined and sharp as with the lead/Linotype alloy.

I don't cut the spruce until I see it turn dull grey whatever time that takes...five seconds or 15 seconds.

Fifteen seconds? Three to five seconds would be about right. Hard to understand how one would go about keeping a sprue unfrozen for fifteen seconds.

It all depends on the alloy and mold temp. Maybe it was just a fluke as I don't recall having that problem before. I haven't used ww's all that much but mostly use 50/50 lead and Linotype for about BHN15. If I wanted it softer, just added more lead. I've had an abundance of Linotype for years due to working in the printing business many years ago and got quite a bit of it that I made into 50/50 mixes but still have the type by itself to mix whenever I need it. WW's are hard to come by in my neck of the woods and a 5 gallon bucket will usually yield only about 25 pounds of it if you're lucky and the rest steel, iron and other junk. What I currently have is from Kathie and it checks out on average as BHN9.4...at least my sample do.

You did hit upon a valid point and one I'm guilty of-added sprues to the pot while I work. It's an old habit that needs breaking.

Not sure I agree with Gary here. I return the sprues directly after knocking. They are still hot, maybe not up to the 675 in the pot, but aren't going to reduce the melt temp significantly.

[cbrick]

Not sure I agree with Gary here. I return the sprues directly after knocking. They are still hot, maybe not up to the 675 in the pot, but aren't going to reduce the melt temp significantly.

Return sprues to the pot? Yes I do, no I don't.

When bottom pouring I don't, I leave a good thick layer of charred sawdust on top and sprues and rejects go back in the pot when I'm finished. Nothing goes back in the pot while casting.

When ladle casting I hold the mold over the pot to pour and as soon as the sprue freezes I open the sprue plate with a gloved hand and drop it right back into the pot. I am using the ladle to keep the melt stirred, the sprues are quite hot as in just short of liquid and with a 40 pound pot the melt temp isn't effected enough to notice if at all.

Rick

[geargnasher]

Echo, I returned sprues straight to the pot for years, in fact until recently. Then I discovered that all those little specks of crud on the surface of my boolits were oxide inclusions from the returned sprues and cull boolits. The cool (or solid) lead will sink in the molten due to density variances, and it takes the oxide coating straight to the bottom, where at least some of it is trapped under the surface of the melt due to the surface tension and weight of the lead on the bottom. This oxide layer doesn't melt, and since there is no way to reduce it at the bottom, it just sits there, slowly migrating toward the spout as the pouring currents take it there. When I quit returning sprues, my boolits cleaned up. I run a very clean pot, stirring and scraping the sides with a stick will keep all the clingy dross wiped off, so the only source for the junk was the oxides of the sprues. Now, I add sprues all at once when I'm refilling the pot with warm ingots, then stir-scrape the bottom with a teaspoon and bring the junk up the sides. Also, I flush the spout prior to casting, running out about half a pound and returning it while still liquid to the top.

Whistler: I too have an NOE thermometer, in addition to a Lyman one and a PID controller with submersible thermocouple. Your readings don't jive AT ALL. Pure lead melts at about 621 degrees F, and the addition of antimony and/or tin LOWER the melt point from there. There isn't a lead-based boolit alloy of which I'm aware that is fully liquid at any point ABOVE the melt/freeze point of pure lead, so something is "rotten in Denmark" as they say. WW alloy begins to "sweat" tin or Sb/Sn (depending on composition) at about 500, is mushy by 550, stirrable by 560, and it hangs out at 570 until suddenly all the much disappears and the last phase of liquifaction takes place. At that point the alloy can take on more heat and the temp rises. I think you need to calibrate your thermometer with pure lead (be CERTAIN it is submerged at least up to the minimum line on the probe!!) or close to pure (roof flashing, for example). If your thermometer shows anything over 621 for a melt point, it needs calibration.

100 degrees over full-liquidus (you can determine full liquidus point of ternary alloys by observing the last flatline in the temperature/time curve, indicating the point at which the final element in the mix is changing phase change to liquid, then just as the temp begins to rise again you know it's fully liquid. Note that temp. Go 100 degrees more and hold the pot temp there. Get your mould hot, and start casting until you get good boolits. If you have a decent alloy and good, clean mould, it will work, I guarantee it. This is where your casting pace and technique are put to the test. If you're doing it right, you can make good boolits as long as the alloy is barely hot enough to pour out of the pot or ladle.

One more thing, you can do the test in the above paragraph finding the exact freeze point, mush phase, full-liquidus, and casting temperature by making a time/temp graph with the calibration of you thermometer the way it is, just make marks on it with a sharpie and forget what the dial says. Just go 100 over full-liquidus and mark that, so you know where your casting temperature should be.

This is what I meant by things not being translated into posts, you have experience from being there that we, on the other end of a phone line, don't, so it's kinda hard to see the whole picture from a few words. You posted like your readings were FACT, and that those supposed facts made the rest of us fools with what we were saying, so you can see how that might ruffle a few feathers when in truth they were just readings, and experience tells my either your thermometer is about a hundred degrees off, it wasn't submerged deeply enough, or you have something badly wrong with your alloy.

Hope this helps,

Gear

[docone31]

Well, there I differ with putting sprues in the pot.
I liberally put sawdust or kitty litter on my pot. The sprues go directly on the litter. Rather than the sprue button dropping into the melt, it drips into the melt. I water drop my wheel weight and the sprue is damp. Heating untill melting on the litter, or sawdust, eliminates the moisture, and cleans the alloy going in.
I find, doing it this way, my mix gets more and more homogonized. Kinda like stirring, but on a lessor scale.
The bottom crud does colletc. I take a long flat blade screw driver, and when the melt is liquid, I scrape the bottom and sides. Even with a clean start, stuff does come to the top. I let it sit on top with the litter.
That is my story, and I stick to it!