Can't get my molds to fill out!

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Last Post 17 October 2007

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PurpleXS posted this 07 January 2007

I've been casting my own bullets for a long time, with no problems. I get my lead by picking up wheelweights from tire dealers locally. I've recently started working on casting bullets to sell, hoping to start a small business so I can quit my job and work from home. I'm presently using mostly Lee aluminum molds, and have had little trouble in the past with them.

Now, all of a sudden, I cannot get the molds to fill out completely. Wrinkles, pock marks, rounded bases, and rounded driving bands are the norm more often than I like. I've added up to 1 pound of 95/5 tin/antimony solder to try to get the molds to fill out, but to no avail. I've turned the heat up as high as it will go (don't have a thermometer yet), with better results, but the bullets are heavily frosted (of course). I'm planning to get a thermometer to check my temperature, but I'm running out of ideas as far as solving this problem.

I am somewhat suspicious of one of the molds I'm using (Lee .44-200-RF) as it seems to be worse about it...the other is a Lee 45-250-RF.

At some point in the future I plan to buy a Magma Casting machine and the iron molds that go with it. I halfway wonder if switching to Lyman or RCBS iron molds will help.

Thanks for any help ya'll can give me with this...it's giving me more gray hair...

Kent White

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14 Comments

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CB posted this 07 January 2007

Kent I have a couple of Lee alum moulds and I have no problem with them. I have a process for prepping the mould before I cast the first bullet with it. I have found that Lee uses a oil based cutting lubricant in their machining process and that oil seems to never burn out. I think it is because the alum is porous. Before I use the mould, I disassemble it then I scrub it out with mineral spirits and a toothbrush. I then boil it in an old pot that holds about a quart of water and add water and 1/2 teaspoon of TSP (tri-sodium phosphate) for about 15 minutes. I drain the water / tsp mixture and refill the pot with clean water and boil it again for 15 minutes. Using some tongs I pull the pieces out and set them on a couple of paper towels to dry. After they dry and cool I reassemble, mount to the handles and head out to the garage to start casting. I have found this works very well, even for moulds I am having a similar problem with that I have owned for years. I would give this a try first before I spent more money on another mould. Any oil or grease that gets into the mould cavity will cause this in my experience. (this includes candle wax, bullet lubes, etc) Let us know if this fixes your problem. Good Luck.

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CB posted this 07 January 2007

Kent,

Are these moulds new or have you used them before with no problem? If new try sticking a corner of the mould in the melt until they stop smoking and see if it helps. You might have to let the thing cool off for a few minutes after you do this but if it's an oil problem it should help. If they're not new and the problem's something that just started it only thing I can think of is something wrong with the mix but I've never had it happen so can't say.

Let us know what happens.

Pat

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Standard Member

Lon posted this 07 January 2007

"Now, all of a sudden, I cannot get the molds to fill out completely." Doesn't that sound like contaminated alloy?

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TRKakaCatWhisperer posted this 13 January 2007

Lon wrote: "Now, all of a sudden, I cannot get the molds to fill out completely." Doesn't that sound like contaminated alloy?

Not with wrinkles too. Something cooled off. Mould is to cold or alloy is to cold or both. Thermostat may have headed south. Cranked up bullets should have been frosty.

The thermostat on mine is at the back - heated by the pot and some cooling from the air. On HOT days the thermostat isn't cooled as well, so it cut off to soon; cold days the thermostat is cooled by the air better and it keeps the melt HOTer.

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Nardoo posted this 14 January 2007

Purple,

When this happened to me I checked everything I could think of starting with my moulds, pot thermostat and even how I was holding my tongue. It turned out I had a contaminated batch of alloy. I dumped it out and cleaned my pot well with some HCl, then neautralised it with Bicarb soda. I got a fresh lot of known alloy and suddenly I was an expert again. Beautiful, shiny bullets that you can just use for looking at.

The pock marks and poor fill out at high temperature seems to indicate you may have this problem.

Nardoo

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Ken O posted this 15 January 2007

His description sounds more like a heat problem then contamitation IMO. Buy a lead thermometer and you will know for sure. Preheat your mold extra long, turn up the pot all the way, and see if the problem goes away. Make sure you see some frosted bullets.

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Lloyd Smale posted this 20 January 2007

I about guarantee its a zinc ww problem. See my post on fluxing. Those are the exact same problems i have had for over a year.

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kidwalli posted this 01 April 2007

Use a Q- Tip and lacquer thinners to thoroughly clean the bullet cavities. Smoke with a Zippo lighter using Ronsonol. That's it.

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Standard Member

buck1 posted this 02 April 2007

"the bullets are heavily frosted “

I'd say its the alloy or a venting problem. I have had to vent some LEE molds. FWIW.........Buck

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Lefty posted this 04 April 2007

How can you identify if you have Zinc contaminating your alloy. When I melted down my last batch of WW, some of the ingots cooled to a texture not unlike dried mud. I assumed this was a bad sign but I don't know what it is a bad sign of.

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Wally Enga posted this 05 April 2007

Lefty wrote: How can you identify if you have Zinc contaminating your alloy. When I melted down my last batch of WW, some of the ingots cooled to a texture not unlike dried mud. I assumed this was a bad sign but I don't know what it is a bad sign of.

It's a lot easier to just make sure you don't get the Zinc contamination. :)

WW will become molten at only a little over 500F and the melting point of Zinc is over 780F. Just as soon as the WW become molten and the clips float to the top --- turn your heat source down and skim off the clips, crud and any Zinc WW's.

By the way, don't just toss out the steel clips. Price of salvage steel is about $135 a ton locally here --- took a few pails to the salvage yard last week and got $15 for them, just enough to pay for another 5 gal pal of WW.

Wally

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cat1870 posted this 12 July 2007

I have a couple of Lee molds. It took about 100-150 bullets til they started to cast good bullets. I did clean the molds 1st before casting. Still......it took about that amount of casting before good bullets were obtained.