Lead Experts- How to test the compostion of lead alloy?

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msg.drew

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All the lead experts out there I have been casting now for a while I am getting pretty serious... ie building my own giant melting pot... its bassically a copy of a lee pro melter super sized... works pretty slick and propane powered... little lever and spout out the bottem just like the real deal... its basically a one off prototype bulid with alot of scrap lying around the garage.

Any how like I said I have been getting pretty serious about casting... due to the fact that you can get lead from different sources... pipes, wheel weights etc... I throw these all into my giant melter and presto lots of ingots...

This is all good and great I got this down to a science... however I want to know how I can test the lead alloy mix that I have for the contents and make the nessary adjustments so all the lead coming out of my melter is the exact same.
 
msg. drew:
It would be best if you sorted your metals by type before you smelt them and keep them separate from a common melt. Stick on wheel weights are mainly lead. Clip on wheel weights are an alloy and are harder. Flashing, plumbers lead is close to pure lead. Linotype is harder yet than w/w but increasingly hard to obtain. Then you can combine your ingots them as required to get the hardness you need.

A hardness tester is helpful but be forewarned that they are not necessarily accurate from one to the other even in the same make. Most will give fairly consistent readings on ingots from the same melt but those readings may not be truly consistent with actual hardness. However, you can combine your readings with actual shooting of bullets made from the alloys and fairly quickly learn the limitations of the alloy. I have a Cabine Tree tester and it is very consistent in it's readings but those readings are several points higher than actual hardness of the metal as lab tested. I am carefully tinkering with the indent point diameter to try to "tune" it to a better representaion.

A scientifically precise hardness tester is very expensive and beyond the needs and probably finances of a home caster.

To actually determine the precise composition of the alloy you would have to send samples to a lab or assay service that is equipped to do an analysis. Probably also too expensive for your needs unless you have a contact in the business.

Not a lot of help here but a hardness tester and sorting your metals before melting will let you work up your own combinations.
 
I wasn't really refering to hardness as I know about testing for hardness... learn that the hard way making 5000 bullets and droping them into water too cool them down ended up way to hard...

What I want to know is lets say I have 200 lbs hot liquid lead from wheel weights... is there someway to testing to determin that the lead has 92% lead 2% Tin And 6% antimony in it?

I am assuming that every wheel weight company uses a different mix
 
msg.drew said:
I wasn't really refering to hardness as I know about testing for hardness... learn that the hard way making 5000 bullets and droping them into water too cool them down ended up way to hard...

What I want to know is lets say I have 200 lbs hot liquid lead from wheel weights... is there someway to testing to determin that the lead has 92% lead 2% Tin And 6% antimony in it?

I am assuming that every wheel weight company uses a different mix
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The only way to get that much detail is to have it assayed and that’s expensive.
I have found that making a bullet and dropping it in water, fetching it out and scratching it with my thumbnail, observing how far it dug in and how well the bullet is formed. Then add tin and antimony accordingly.
In changing the composition of a large pot full you will need lots of tin(bullet forming) comes in a large roll from plumbing shops and antimony(hardness) my source is reclaimed lead shot..
 
msg.drew:
See second to last paragraph. I haven't researched it much but possibly a spectrograph or other similar type of equipment is required. Other than that you can make a bit of a guess from the hardness of aircooled metal compared to references in casting manuals.

Wheel weight metals composition seems to have changed over time and it is possible that different makes vary their content. I believe the antimony content and possibly arsenic have been reduced. I think some are also using recycled wheel weights and some small parts of the original metal mix may be lost through oxidation etc. during resmelting.

Unless you are near a smelter and can make large weight purchases of specified alloy mix or the individual metals it's kind of a crap shoot. But, it doesn't really have to be that precise for most purposes.

I believe the emphasis on hard cast bullets is greatly overstated and I rarely use them that way any more. Wheel weights with about 2% Sn added and air cooled make good hunting and target bullets for most purposes up to about 1900-2000 fps. It does vary a bit depending on calibre, twist rate etc. They might even be too hard for some low velocity purposes in revolvers. Certainly the buck I took yesterday with an 8 X 57 was killed effectively with one of that type and it was loafing along at about 1600 muzzle.
 
I am looking at make large volume pistol bullets for resale... I got prices from a large smelter and they wanted $800 for 200 lbs of bullet lead I bought the same amount for $30 and have been casting large lots 5000pcs and test shooting them without any problems from wheel weights... range lead... and scrap...

Its just I sell alot of quality brand name products and want my own bullets to match that quality, I have invested in magma products for the manufacturing and want my efforts to be worth the time I spend doing this...
 
Hardness reflects how much tin is in the mix, with or without the antimony. But the antimony is required so the tin alloys properly so the bullet does not lead the barrel.

A no-antimony bullet would test hard but lead the barrrel like a pure lead bullet. So far as I know, the only way to make sure there is enough antimony is to add some linotype yourself. At least, that is what I do because I don't know how to test for antimony content.
 
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To test my home cast bullets I make, I use a Saeco Lead hardness tester, It's repeatable and gives me a good indication how consistant my bullets/ingots are batch to batch.

Now this doesn't get me what the comosition of the metal is but gives me a reference point to work with in case I need to soften or harden my mix.

My standard mix is 4 parts WW, 1 part linotype with 2-3 % pure tin mixed in. Works for pistol and rifle bullets up to 2400 FPS with no leading.
 
I see where you're going, but without laboratory equipment it's futile, and pointless anyways. You can get pure lead and pure tin to make 1:40, 1:20, etc. and then theres wheelweight. If ou must have a specific mix, you'll need to approach a reputable foundry and be willing to pay for it.

Keep pure lead (pipe, stick-on weights etc. separate) With Wheelweight, you can't be sure what you're getting, but it will be about 95% lead, 1% tin, and 4% antimony +/-. What you can have is some assurance that what you've got is consistent, and you can estimate what you do have. Here's one way: get small bits of known alloys e.g. pure lead, lead plus 5% tin, and Linotype to use as standards. Test it for hardness and record it. Cast bullets from whatever mold you are using at the time, and make sure that you have complete fill-out (keep it separate as it can be re-used). Then with the same mold, cast some "mystery" alloy and compare weights - the lead is the heaviest and softest, the Linotype the lightest and hardest, and all else (e.g. wheelweight) will be in-between. Cast in big bunches and sort by weight - that gives you consistency and accurate shooting.

Otherwise, find a foundry.
 
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Ok seems like I am going over kill here... I have a tested working product why go looking for more trouble then what is nessary.

Just wondering... is there a way to seperate the componts of the alloy once they are combined... ?
 
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