3 hours of casting for 20 good boolits

[Jailer]

This has by far been the most frustrating casting session I've had so far. I had better luck my very first time than I did tonight.

Got my new Accurate Molds 3 cavity aluminum 45-220W in the mail today and man is it a work of art. Absolutely gorgeous mold. Scrubbed it down vigorously in hot soapy water, sprayed it out with break cleaner lubed it and went to casting. Had a heck of a time getting the thing to fill out. I'm casting WW with about 3% tin added. I tried all sorts of combinations of mold and melt temps and no matter what I did I just couldn't get good fill out with it. The only way I could get it to fill out completely was to run the melt at over 850 deg and slow my pace wayyy down to keep the boolits from frosting badly. Only thing is it made them drop about 2 grains light by doing this.

I've had real good luck with Lee aluminum molds running the melt a little hot (between 700 and 750) and keeping them just on the edge of frosting to get good fill out but no matter what I tried I just could find the balance point with this mold. It either drops extremely frosty boolits or poorly filled out boolits, nothing in between.

I'm thinking I should have ordered the mold in brass and maybe I'd be having better luck. Could it be this mold needs a few heat cycles to start working properly?

Any suggestions?

[Three-Fifty-Seven]

Yeah, give it a few more try's.

[462]

Yep, sometimes it takes a few casting sessions for some moulds to be right. Don't despair, just yet.

[9.3X62AL]

Clean it some more. Sounds like it might be out-gassing cutting oils. Use HOT HOT HOT BOILING WATER, poured right from the pot into the kitchen sink, over the mould blocks after scrubbing with soap and warm water. I started this regimen with new moulds, and their behavior improved markedly and immediately.

As with most things related to casting--heat is your friend.

[geargnasher]

First, understand that MOULD temperature affects boolit quality, ALLOY temperature affects ALLOY quality and amount of heat transferred to the mould each pour, which THEN affects boolit quality. Frosty boolits are made by hot MOULDS, not by pouring a hotter alloy into the mould.

Try Onandaga's "Swirl Pour" method. Tip the mould down on the handle end about five-10 degrees, drop the alloy about 3/8" from the spout to the sprue plate, and drop that stream RIGHT AT the edge of the sprue hole, either on the right or left side of the hole (NOT the front or back). This will cause the stream to enter at an andle and to the side, relative to the cavity. This creates a natural swirl effect which helps fill the bands and gives the air in the cavity some inertia as it, too, spirals it's way out the side of the sprue hole opposite the lead stream, making a double-helix of lead going in and superheated air going out.

Tom's moulds lock up and seal like Fort Knox, so I often find it necessary to swirl pour to make good band and base fillout, since the air doesn't vent out anywhere else.

For better bottoms, you can very slightly "break" or bevel the top edge of the mating halves of the blocks to form a "vee" channel connecting the bases, just a slight one helps make up for the hermetic seal of the sprue plate and lets the bases vent just enough to fill out. Dont' overdo it or you'll have horns on your boolit bases. Cheaper moulds naturally vent the bases because the poor sprue plate fit, machine marks, scratches, galling, etc. BABore machines vents for his sprue plates, a very good idea IMO.

You are running the ragged edge of overtinning your alloy, if you have more tin than antimony the tin will condense out first upon cooling, making some weird patterns and surface hardnesses on your boolits. If you use brass moulds, an overtinned alloy will tin the cavities.

I'd stick with about 700 degrees and practice swirl-pouring while casting at a rate that gets your mould hot enough for a light, even frost on your boolits (the kind that wipes right off with the twist of a rag revealing a shiny boolit surface beneath).

Gear

[RobS]

All great advice. I've found that my aluminum Accurate Molds take a bit longer to heat up vs a lee mold but then will hold the heat better. Having a hot plate helps this as you can get your mold up to temp before you even start casting and with an appropriate alloy temp it then leaves one variable, casting tempo. If you don't have a hot plate you can try dipping the corner of the mold in the melt to bring the mold temp up. I don't personally don't do this as I never liked the idea of changing my pot's alloy temp by dipping a cool mold in it and I also put a layer of sawdust on the top of my alloy to help with alloy oxidation. I do have my WW alloy hotter when casting with my Accurate Molds as my tempo isn't as fast as some casters.

[Jailer]

Clean it some more. Sounds like it might be out-gassing cutting oils. Use HOT HOT HOT BOILING WATER, poured right from the pot into the kitchen sink, over the mould blocks after scrubbing with soap and warm water. I started this regimen with new moulds, and their behavior improved markedly and immediately.

As with most things related to casting--heat is your friend.

I think I will give it one more good hot cleaning and try what you have suggested. It did take a while to get the wrinkles out so maybe I didn't get it clean enough.


First, understand that MOULD temperature affects boolit quality, ALLOY temperature affects ALLOY quality and amount of heat transferred to the mould each pour, which THEN affects boolit quality. Frosty boolits are made by hot MOULDS, not by pouring a hotter alloy into the mould.

Try Onandaga's "Swirl Pour" method. Tip the mould down on the handle end about five-10 degrees, drop the alloy about 3/8" from the spout to the sprue plate, and drop that stream RIGHT AT the edge of the sprue hole, either on the right or left side of the hole (NOT the front or back). This will cause the stream to enter at an andle and to the side, relative to the cavity. This creates a natural swirl effect which helps fill the bands and gives the air in the cavity some inertia as it, too, spirals it's way out the side of the sprue hole opposite the lead stream, making a double-helix of lead going in and superheated air going out.

Tom's moulds lock up and seal like Fort Knox, so I often find it necessary to swirl pour to make good band and base fillout, since the air doesn't vent out anywhere else.

For better bottoms, you can very slightly "break" or bevel the top edge of the mating halves of the blocks to form a "vee" channel connecting the bases, just a slight one helps make up for the hermetic seal of the sprue plate and lets the bases vent just enough to fill out. Dont' overdo it or you'll have horns on your boolit bases. Cheaper moulds naturally vent the bases because the poor sprue plate fit, machine marks, scratches, galling, etc. BABore machines vents for his sprue plates, a very good idea IMO.

You are running the ragged edge of overtinning your alloy, if you have more tin than antimony the tin will condense out first upon cooling, making some weird patterns and surface hardnesses on your boolits. If you use brass moulds, an overtinned alloy will tin the cavities.

I'd stick with about 700 degrees and practice swirl-pouring while casting at a rate that gets your mould hot enough for a light, even frost on your boolits (the kind that wipes right off with the twist of a rag revealing a shiny boolit surface beneath).

Gear

The bases are filling out perfectly. The nose and the base as a matter of fact. It's the lube grooves in the middle that are giving me fits.

It's weird. The base is perfectly flat and well filled out. The nose and first driving band are well filled out. The lube grooves and center driving band between the lube grooves are where the problems are. I should have saved a few and took some pics but I was so frustrated I threw them all back in the pot and called it a night.

[Jailer]

All great advice. I've found that my aluminum Accurate Molds take a bit longer to heat up vs a lee mold but then will hold the heat better. Having a hot plate helps this as you can get your mold up to temp before you even start casting and with an appropriate alloy temp it then leaves one variable, casting tempo. If you don't have a hot plate you can try dipping the corner of the mold in the melt to bring the mold temp up. I don't personally don't do this as I never liked the idea of changing my pot's alloy temp by dipping a cool mold in it and I also put a layer of sawdust on the top of my alloy to help with alloy oxidation. I do have my WW alloy hotter when casting with my Accurate Molds as my tempo isn't as fast as some casters.

My hotplate died half way though my casting session tonight. It just wasn't a good night.

[RobS]

That does suck...........nothing going right. I've had those days and miserable they are.

[RobS]

The bases are filling out perfectly. The nose and the base as a matter of fact. It's the lube grooves in the middle that are giving me fits.

It's weird. The base is perfectly flat and well filled out. The nose and first driving band are well filled out. The lube grooves and center driving band between the lube grooves are where the problems are. I should have saved a few and took some pics but I was so frustrated I threw them all back in the pot and called it a night.

I had this issue with my 300 grain mold. I increased alloy flow from the pot and it cleaned up the lube groove fill out problems. Seems as if the molds don't vent as well near the lube grooves.

[geargnasher]

+1 RobS, that's a good solution. Finding the fill rate the mould prefers is crucial to fillout, regardless of other factors.

Uneven mould temps also can do this, many moulds seem to overheat the middle part first for some reason, causing hourglassed boolits and poor middle-band fillout. As has been mentioned, but I'll say again in the context of poor midship fillout is BREAK IN. Some moulds just need three or four full-on casting cycles of 20-50 boolits each to get "broken in", after that things get much better like good wine. Steady as she goes and the temps will even out after a while, just cast, don't look, just cast for about 50 at three pours a minute steady with the pot at 700 or even 725 and THEN take a peek at what's falling out.

Gear

[mpmarty]

I've got a door stop that used to cause problems like yours.

[Piedmont]

I have that same exact mould. Same cherry, same 3 cavities, and mine is aluminum, too. The problem isn't that you didn't get brass. Mine casts just fine.

You don't have to use a hotplate. You can dip a corner of the mould in the melt for about 30 seconds, then dip the projection off the sprue plate in for another 20 or so seconds and it will be heated sufficiently to cast. My last casting session I used two moulds to give enough cooling time between pours.

Could you have maybe gotten some mould lube in the cavities?

If it were me I would put some rubbing alcohol on a Q tip and swab the cavities and then just give it another go. If you have some residual oil in there it is just a matter of time until it burns out.

BTW I don't have to do any fancy lead swirling with either my Accurate moulds. I wouldn't alter the mould. Best to just try a few more sessions and if it doesn't shape up contact the mould maker for advice.

[ss40_70]

like 462 ive learned that it takes a few casting cycles for new molds to break in , like most advise give it a few tries .. next time you get a chance to cast try getting the mold up to temp and then let it cool down a couple times i'd bet a case of your fav beverage that it starts droppin pretty boolits after a few heating cooling cycles

[Dale53]

Jailer;
You have received good advice here. It is most likely one of two things. Either the mould is not quite clean (I personally use a toothbrush and Dawn dishwashing liquid soap then rinse in VERY hot water and pat dry). I pre-heat with a hotplate.

Sometimes it DOES take a couple or three cycles to break in a mould.

Then, sometimes, I think the planets are not aligned. A couple of years ago, I started casting with a well used and broken in mould that flatly defied my best efforts. I have only had that happen a couple of times in probably three hundred thousand bullets. Nothing I did seemed to work. Finally, before I let my frustration get the better of me, I quit.

The next day, with the same mould, the same pot of metal, and the same operator (me) everything was smooth as silk. I have NO idea what caused the problem. NONE whatsoever. It just did! Haven't had that problem since. My brother used to have a hat that said, "Sh$t Happens" - sometimes, I believe it.

Dale53

[Bret4207]

Jailer, as gear said, don't confuse alloy/pot temp and mould temp. It's possible to get really hot alloy to work fairly well in a cool mould, but the boolits won't fill out quite right. I'm betting a few casting sessions and this mould will figure out it's purpose in life is to makes you happy.

[44man]

My hotplate died half way though my casting session tonight. It just wasn't a good night.
There is a heat fuse in the bottom of the plate, under some shrink tube. Our plates get hotter then they do when cooking and the fuse will blow.
I just bypass it. If you buy a new hotplate, it will also fail shortly.

[GabbyM]

I've had fairly good luck with electric contact cleaner in a spray can for cleaning moulds. Seams to work better than brake cleaner but that may be coincidence. At any rate it probably just needs broken in.

I’d hesitate to run lead over 800 degrees. About 750 is plenty hot.

[Jailer]

44man thanks for the tip. The heat fuse was blown and is now bypassed and the hot plate is up and running again.

Now to get to casting again and see if I can have a better go of it this time.

[fecmech]

I would be very careful with what kind of soap you use. I recently cleaned a 6 cav Lee with Dawn detergent BUT it had the Olay hand renewal in it. It took me one heck of a long time to get that mold to cast and I had to clean it numerous times with contact and brake clean after the initial soap clean. I thought I'd try the soap routine that others use but in the future I'll go back to my old Brake clean routine. I've never had a problem with that.

[plainsman456]

I use the Dawn with bleach.
It's the only kind the wife buys these days and rinse in boiling water.
Sometimes the water heater temp will not be hot enough to get it done.

[rond]

I smoke the cavities of lee molds with a match to get started, after a few sessions they seem to break in.

[fredj338]

Try "pressure" casting. Hold the spout tight to the spru plate & fill, then form the spru. This is pretty much how I do all my bottom pour casting. The MagmaCaster is the only time I do not.

[Three-Fifty-Seven]

The nice thing about bad days is . . . they end at midnight, if you do! :groner:

[Heavy lead]

The swirl technique illustrated by previous posters is a huge factor, in fact I use it with all of my moulds and it helps fillout on all of them, never pour it right down the sprue hole.
The mould I got from Tom I never cleaned with soap and hot water, just two rounds of denatured alcohol and went to it. It's brass, however usually I find aluminum to be a little faster up to speed, but also with aluminum, especially NOE moulds I find I need to cycle them per instructions a couple of times to reach optimum results.

[leadman]

Also there is nothing wrong with frosted boolits. They are usually filled out better than a shiny boolit, all depends on the mold.
I would let your mold get hotter in the next session. If you start seeing little pockets in the boolit then you know it is not clean enough.
You can also use a toothbrush and kitchen cleanser to scrub the mold surfaces. I have done this to several contrary molds and it has helped.

[onondaga]

I have declared Brake Cleaner illegal for mold cleaning because it leaves petroleum in the aluminum. The petroleum heats up at casting temps and caused the problems you are getting, That and mold temperature. Boiling soapy water is great, following that with brake cleaner contaminates the mold again. If you just have to use a solvent to be happy, Acetone is harmless.

Gary

[Swede44mag]

I use Acetone as well I apply it with q-tips it works for me.

[mroliver77]

I have let oil contaminated molds set on the hotplate for an hour and burn off the bad stuff. Not recommended cleaning procure but it will work.

The only thought I have is to ask how far is your mold from the spout? Some molds don't seem to matter while others need to be very close. The alloy is oxidizing while you pour. Closer to spout gives less time for air to act upon the alloy.
Jay

[Jailer]

Ran into another snag this afternoon. My sprue plate seized to the pivot bolt so I had to take it apart and fix that. Spent the afternoon taking care of that problem but it seems to be fixed.

Well the mold has been cleaned again in HOT soapy water. I was using Palmolive but picked up some Dawn just in case that mattered. Rinsed in hot water followed by a rinse with a large pot of boiling water. It's on the hot plate and them melt is coming up to temp so we'll see in a bit how things turned out.

[Jailer]

Well that was time well spent. :roll:

Zero. That's the number of usable boolits I got from this mold this time around. I just can not figure out what is going on with it. It just will not fill out the center of the boolit. I get soft edges around the lube grooved in the center. The top and bottom are perfectly filled out.

I'm about to give up on this mold. If it were a $20 Lee mold it wouldn't bother me so bad. This is my first custom mold and it cost me over $100 and I can't get it to throw a good boolit to save my life.

[RobS]

Give us a bit more info as to what you did for casting temp this time around, method of pouring into the mold, adjustment to alloy flow etc. Any changes this time vs last.

[Jailer]

Give us a bit more info as to what you did for casting temp this time around, method of pouring into the mold, adjustment to alloy flow etc. Any changes this time vs last.

Basically, you name it I did it. Cool mold cool melt. Hot mold cool melt. warm mold warm melt. Hot mold hot melt (best results but still poor fillout). Swirl pouring, pressure casting. Mold close to spout (1/4 inch) mold further from spout (3/4 inch).

I tired melt temps as low as 620 deg (coolest my spout would function at) and as high as 800 deg and a bunch in between. I tried casting fast and casting slow. Tired opening the mold between casts and leaving closed. No matter what I tried I could not get good fillout on the lube grooves. The best I got was running the melt close to 800 deg and casting as fast as I could. They filled out much better but were EXTREMELY frosted. Hot melt, hot mold and fast casting seemed to be the only thing that got me going in the right direction but the results were boolits so frosted they were underweight and very inconsistent.

I'd like to try again but I have no idea what to try to get it to work.

[onondaga]

It is unfortunate to say, but you just don't get it. I look at part of your opening post,

"I've had real good luck with Lee aluminum molds running the melt a little hot (between 700 and 750) and keeping them just on the edge of frosting to get good fill out but no matter what I tried I just could find the balance point with this mold."

Jailer, if you have to run your pot at 700-750 to convince your mold to be hot enough, it is simply that your work cadence is too slow to maintain a good mold temperature. Wheelweight with added 3% added tin can easily be cast at 600 degrees with my work cadence slightly sped up.

Then later:

"I just can not figure out what is going on with it. It just will not fill out the center of the boolit."

Get over it, your mold is too cool and unevenly warmed from the start and never brought up to working temperature due to your slow work cadence.

Some people are marvelous at casting, I envy the talent of CowboyT and how well he does with 6 cavity molds in his videos. I only use 1-2 cavity molds and have never tried a 6er because of my skill level and I have been casting since 1957 and have worked as a professional consultant and educator in casting techniques for a precious metal refinery Education Dept.. You will have to quit thinking your cadence is fine and speed up or you will likely never be happy with your nice new mold.

Stop believing that your new mold should behave the way you want it to and work with what the mold needs to work properly.

My experience tells me that you will need at least 3-4 drops a minute to get decent results with the mold warmed to within 100 degrees of your alloy flow temp. If you can get that cadence and mold temp and are still getting poor results there is likely additional flaws in your casting technique, but last of all mold quality would be suspect--a tiny gate hole will cause what you are getting, a long pour stream will cause what you are getting. 1/4 to 1/2 inch stream is ideal.

The classic reason for cold or hot zones showing up in castings is 'Cold Short" caused by dead center pour gurgling into the gate hole causing turbulence and cutting off air escape during the pour.. Research my posts/replies and learn Swirl Casting to cure that.

Gary

[Jailer]

It is unfortunate to say, but you just don't get it. I look at part of your opening post,

"I've had real good luck with Lee aluminum molds running the melt a little hot (between 700 and 750) and keeping them just on the edge of frosting to get good fill out but no matter what I tried I just could find the balance point with this mold."

Jailer, if you have to run your pot at 700-750 to convince your mold to be hot enough, it is simply that your work cadence is too slow to maintain a good mold temperature. Wheelweight with added 3% added tin can easily be cast at 600 degrees with my work cadence slightly sped up.

Then later:

"I just can not figure out what is going on with it. It just will not fill out the center of the boolit."

Get over it, your mold is too cool and unevenly warmed from the start and never brought up to working temperature due to your slow work cadence.

Some people are marvelous at casting, I envy the talent of CowboyT and how well he does with 6 cavity molds in his videos. I only use 1-2 cavity molds and have never tried a 6er because of my skill level and I have been casting since 1957 and have worked as a professional consultant and educator in casting techniques for a precious metal refinery Education Dept.. You will have to quit thinking your cadence is fine and speed up or you will likely never be happy with your nice new mold.

Stop believing that your new mold should behave the way you want it to and work with what the mold needs to work properly.

Gary

Honestly I'm not sure how I could speed it up more. I pre heated the mold on the hot plate before I started. When I try to cast at a lower melt temp I get very poor fillout. I can only cast as fast as the sprue will solidify. As soon as it is solid enough to cut, I cut it drop boolits and start filling the mold again. When the sprue is taking between 6 to 8 seconds to solidify and cuts with a flick of a the thumb I think the mold is plenty up to temp. When it starts to take longer that's when things get frosted and with a lower melt temp they are still not filled out completely.

Frosted from a hot mold and poor fillout. How do you correct that?

[462]

"Stop believing that your new mold should behave the way you want it to and work with what the mold needs to work properly."

Now, that should be posted in extra-large font at the top of each sub-forum page.

I came to the conclusion that each mould has its unique character, wants and needs, and it's imcumbant upon us casters to understand what they are. Sometimes, it ain't easy.

Don't berate the mould...it only know how to do it's job one way.

[onondaga]

You will have to go back to basics. Run this experiment until you get ONE good bullet when casting into only ONE cavity of your mold:

1) Each time you begin this exercise begin with pot temp 650, Cold mold. Hotplate pre-warmed medium high about 575.

2) Place mold block on hot plate in a very repeatable way that will be the same every time. Time warming the mold block. Start at 1 minute warming and then immediately pour into one cavity noting on paper solidification of the sprue time.

3) Cool your mold completely and repeat the mold warming but adding 30 seconds to the warming time and immediately cast as before noting sprue solidification time

4) Keep repeating step number 3 with the longer warming increases and casting one single cavity until you get one perfect cast bullet that is about 5-10% frosted evenly on the entire bullet and not a mirror shiny bullet.

The result is that you have figured exactly how you have to heat your mold to get one good cast bullet. Use the middle cavity that you are having the most difficulty with.

Next keep casting that one cavity alone till you can develop a cadence that gives repeated good results.

That cadence that gives good results with one of the three cavities only being used is NOT, I repeat NOT too fast when using all the cavities of the mold, probably just about right but you will have to pour into all the gate holes in the time you previously poured into only one,,, so you will have to speed up more.....Watch CowboyT on his 6ers. He casts so fast that he has to cool his molds, but he could modify his cadence to not need the cooling. Getting an exact balance in casting cadence is a developed skill to learn and doesn't just come on demand because you want it and expect it.

Gary

Be patient and try again.

Gary

[high standard 40]

I have one of the NOE group buy molds, 460 350gr and tried all of the above methods to achieve good fill out. Scrub, re-scrub, heat, scrub some more, and no luck. Hot metal, hotter metal, hot mold, not so hot mold, swirl fill, pressure fill, all failed to get the fill-out I wanted. I was getting bullets I could use but not the perfect fill-out I sought. I finally yielded and bought a ladle. I had always cast with a bottom pour pot and gotten good results till I tried that big old slug. The ladle solved my issues on the first session. I still use the bottom pour pot for just about everything else I shoot. But when I need to cast a few of those big bullets, I'll be using the ladle. You may want to give that a try. And as stated by others here, there is a difference between hot metal and a hot mold. I get better results when I let the mold cool some before the next pour when using a high melt temp.

[Jailer]

You will have to go back to basics. Run this experiment until you get ONE good bullet when casting into only ONE cavity of your mold:

1) Each time you begin this exercise begin with pot temp 650, Cold mold. Hotplate pre-warmed medium high about 575.

2) Place mold block on hot plate in a very repeatable way that will be the same every time. Time warming the mold block. Start at 1 minute warming and then immediately pour into one cavity noting on paper solidification of the sprue time.

3) Cool your mold completely and repeat the mold warming but adding 30 seconds to the warming time and immediately cast as before noting sprue solidification time

4) Keep repeating step number 3 with the longer warming increases and casting one single cavity until you get one perfect cast bullet that is about 5-10% frosted evenly on the entire bullet and not a mirror shiny bullet.

The result is that you have figured exactly how you have to heat your mold to get one good cast bullet. Use the middle cavity that you are having the most difficulty with.

Next keep casting that one cavity alone till you can develop a cadence that gives repeated good results.

That cadence that gives good results with one of the three cavities only being used is NOT, I repeat NOT fast enough when using all the cavities of the mold.

Be patient and try again.

Gary

Thanks for the tip Gary. I think you are right on the money about having to go back to basics. I think maybe I got caught up in trying too many things in one session and may have skewed my results because of it.

[onondaga]

That sounds great. Bear in mind that your cadence is too slow if bullets come out shiny and your cadence is too fast if your bullets come out over frosty. dont change the pot temp to compensate. 650 is plenty hot to get great results.

Gary

[onondaga]

That sounds normal. I have about 3 dozen molds, one of them will only cast with a ladle and one of them will only pressure cast! They are all a little different. I keep notes on the mold boxes for pot temp, alloy, warm time and those special annoying notes like---"pressure cast only" and "ladle cast only". Both of those difficult molds are large caliber hollow base molds. One is a Lee the other is Lyman.

Gary

[longbow]

+1 for what Gary is telling you.

I find my brass moulds and my NOE aluminum moulds demand a faster cadence to keep them hot enough to get good boolits when compared to iron moulds or Lee aluminum moulds.

I pre-heat the mould until it smokes (when the sprue plate lube starts to smoke it is hot enough to cast and maybe a bit hotter than you want) and I make sure my lead is at good temperature. Since I do not use a thermometer I can't tell you exact temperatures but as has been said you have to let the mould tell you what it wants.

If I have a "stubborn" mould that gives round edges, wrinkles, poor fillout, etc. it usually means it wants a faster cadence. I run lead hot enough and casting speed that my sprue puddle stays soft long enough for me to pick up a dowel to open the sprue plate. As the puddle goes to stiff mush I cut and keep going steady ~ don't stop to admire the boolits or the mould will cool.

I just bought a mould from Accurate and it is beautiful. I did zero mould prep like I usually do (different strokes). I pre-heat a new mould until it smokes then cast away and I seldom have trouble. If I do I cast faster and that solves pretty much all problems for me. I tend to cast slightly frosty boolits as I find I get better fill out.

Watch that sprue puddle start to harden then tap it with the dowel and when it is stiff but not hard cut, dump, close, cast again. Repeat until you have a pile of boolits.

Longbow

[geargnasher]

Another big +1 GARY!

Couple of things I noticed reading over the thread again. Jailer, you said you were casting as fast as you could while waiting on the sprue to cool. What does that mean? Are you waiting until it's rock-hard or what? When casting with an alloy similar to yours that has a long slush or mush stage that I like to cut the sprue by hand, or rather by THUMB while it's still soft, but JUST set enough not to smear lead on the blocks. I wait a full two seconds after cutting to let the bases set a tad more, then dump the boolits and quickly close the mould/sprue plate/pour another round. The only waiting is for the sprue to harden just enough to cut it. If you're beating the sprue plate open with a mallet, you're waiting too long. There is more than one way to do this, but if you follow the techique Gary, Bret, and I are trying to illustrate, your boolits should have a slight puckered crater in the bottom when they cool, contrary to popular wisdom.

Your alloy should be molten at around 540F, and if you let the pot sit for about 15 minutes after reaching 650 and the spout still won't pour freely, you either have contaminated alloy, debris in the spout, a junk thermometer, or are on some other planet. You DO NOT need to crank the heat more than that, I recommended a bit higher earlier because I suspected that you, like so many others with casting problems, don't know how to cast fast enough to get a heavy heat sink hot enough to cast properly.

Three to four pours a minute after preheating the mould, TIME IT. Cut the sprue when it's soft enough to crumble up like a lump of packed brown sugar when dropped onto a hard surface.

Also, controlling the SIZE of the sprue is how I control sprue plate temperature, which affects boolit base quality. If the bases start getting rounded, I pour a bigger puddle until they work again and then tune it down some to maintain.

You REALLY need to get some Bullplate Sprue Lube to fix your binding issues, I think you have to be the first person I know that's ever had one of Tom's moulds bind. In the meantime, pull out the sprue plate pivot screw and lube the bushing, screw threads, inside of the hole, and around the hole with a trace (the stuff goes a LONG way) of Permatex Anti-seize lubricant, available in tiny plastic sample packs (like mustard or catsup) at autoparts stores, sold or given away for lubricating spark plugs that go in aluminum cylinder heads. A full-sized bottle with a brush in the lid is expensive.

Each mould is indeed unique, like our guns and other tools, so listen to what it tells you. You might grab one of your known-good Lee moulds and get back in the swing of using it for a bit, observe carefully what works and doesn't. This will also prove out the soundness of this particular pot of alloy.

If all else fails, send it to me with 20 lbs of the alloy you're using and I'll be glad to dope it out for you and give you an exact recipe, then ship it all back on your nickel.

Gear

[onondaga]

Good tip on puddle size, that rarely gets mentioned for controlling sprue plate temperature.

Gary

[geargnasher]

I smoke the cavities of lee molds with a match to get started, after a few sessions they seem to break in.

I've found smoke to be totally unecessary, even detrimental, to mould function. You get near MY custom-made $120+ moulds with a match and we're going to have problems! Same goes for my fleet of El Cheapo Supremo Lee moulds. Soot masks the issue caused by the machining oil in the aluminum pores, creates undersized boolits, insulates the mould surface (not a good thing), and causes issues with detail fillout. The folks at Lee Precision were smoking the same bowl of Crack when they came up with that that they were smoking when they decided that Alox/beeswax boolit lube was a good lubricant for sprue plates and mould alignment points.


I've had fairly good luck with electric contact cleaner in a spray can for cleaning moulds. Seams to work better than brake cleaner but that may be coincidence. At any rate it probably just needs broken in.

I’d hesitate to run lead over 800 degrees. About 750 is plenty hot.

For all the people that somehow missed it before, please understand the fact of metallurgy that causes the precious tin we add to be rendered totally ineffective and impotent as a fillout aid above 750 degrees. Tin forms a THIN and very dynamic oxide layer on the surface of the molten metal, thus protecting the other metals from further oxidation. This is especially important with the stream of molten metal going into the mould. If your alloy is too hot, the tin oxide is overcome by the other metals and you get what is in effect a higher surface tension to your alloy. This higher surface tension means you have to go even hotter with the alloy for good fillout, and that has it's own set of problems. So either stay well under 750 (100 over full liquidus is PLENTY, usually about 650-675 with WW alloy, 575 with straight Linotype), or don't use any extra tin.

Gear