wheel weight substitute

[JaxCatm]

Lead wheel weights have been outlawed in my area for sometime. Would the Rotometal mix of antimonial lead 4-6% antimony the remaining balance pure lead suffice in place of wheel weights?

[mtngun]

I haven't tried it, but your suggestion sounds right. 3.5% - 4% antimony would be plenty.

You might want to sprinkle in a little arsenic-containing shot, just for the arsenic content, if you plan on heat treating. It doesn't take much arsenic and the exact amount is not critical.

You'd think the foundries would begin offering wheelweight alloy now that it's getting hard to find at tire shops.

[Pa470]

I am unfortunately in the same boat as jaxcatm. However I do have a stock of the rotometal "hardball" at 2/6/92 and some pure lead. I plan to cut the hardball at 1part hardball to 2parts pure lead to approximate the tin and antimony percentages of wheel weight. If I couple this with <1% shot will I be able to harden this sufficiently for medium velocity rifle (1800fps)? Or should I try to cut it to a closer to 1:1 for hardball to lead and skip the hardening?

Sorry for the newbie questions about blending. It would be so much easier if I could just get wheelweights but that isn't going to happen.

[mtngun]

1 part 2/6/92 & 2 parts pure ? So you'd end up with 0.7/2/97 if I'm doing the math right in my head ?

How 'bout 1 part 2/6/92 and 1 part pure for 1/3/96 ?

You'd still prolly want to harden it, though the only way to know if the hardening is helpful is to shoot it both ways.

I long for the old days when service stations had 55 gallon drums of wheelweights they were glad to give away.

[Pa470]

Thanks for the advice. I'll mix 1to1, and try both hardened and non..

Btw the mold i ordered looks excellent!

[mtngun]

Let's hope that foundries step up to the plate and begin offering wheelweight ingots for sale. In the meantime here are some suggestions on how to brew your own wheelweight alloy from common foundry alloys.

For all of these homebrew recipes you may need to add a spoonful of lead shot to boost the arsenic content, though arsenic is a naturally occurring "contaminant" in most lead alloys so it may not be necessary unless you are using 99.99% pure lead.

Also note that while we think of things like stick-on wheelweight, lead sheeting, lead radiation shielding, and lead pipe as "pure" lead, in most cases they actually contain 0.5% - 1.0% antimony and also a little arsenic, so that works to your advantage if you use them for the "pure" lead in these recipes.

3 parts pure lead
1 part linotype
spoonful of lead shot, if needed.
= 1% tin, 3% antimony, and 96% lead

1 part pure lead
1 part hardball alloy (92/6/2)
spoonful of lead shot, if needed
= 1% tin, 3% antimony, and 96% lead

You can also buy antimony or antimony/lead blend from Rotometals, then add it to pure lead. Pure antimony will not melt in your lead pot though. Not sure if you can melt it with a propane torch while it floats on top of the pot? I'll have to try it sometime.

As for whether or not you need to add lead shot, that is easy to determine if you have a hardness tester. If your heat treated bullets are 21 - 30 BHN then you are good to go. If they're not as hard as normal heat treated wheelweight then add a spoonful of lead shot and try again. Only a trace amount of arsenic is required. The arsenic content of lead shot varies quite a bit and the manufacturer won't necessarily tell you how much it contains, so trial and error may be required. Other additives like sulfur can be substituted for arsenic as discussed in Wiljen's article.

[mtngun]

I see that Rotometals offers reclaimed shot, advertised at about 5% antimony. If it really does have 5% antimony then just add 1/2% tin and you'll have extra hard wheelweight. Shot already contains arsenic so no worries there.

Rotometals is also offering what they call "antimonial lead ingot," at 3% - 5% antimony. My guess is that their mystery ingot is simply reclaimed lead shot, because if it were a true foundry metal then they would know the exact antimony content. It's cheaper to buy their reclaimed shot and melt it yourself.

I ordered some of their relaimed shot and also some of their 30% antimony and will be posting a report on it. I'm looking to recreate Dennis Marshall's "wheelweight on steroids" that contained 5% antimony and could be heat treated to 35 BHN.