Warhorse
Member
After several years of using a long-ago collection of wheel weights for casting, I recently obtained a bunch of used wheel weights for a lead source. I am aware that the industry is starting to use zinc instead of lead for wheel weights, at least in some places.
Now the problem. For casting purposes, you definitely do NOT want the lead contaminated by zinc. It causes all sorts of problems, generally resulting in the need to discard a batch of lead.
I am pretty sure that zinc has a significantly higher melting point than lead but am not sure how careful you need to be to separate out the zinc weights from the lead and, if one gets into the melting pot anyway, how obvious is it that it is not lead before it begins to melt into the lead? Fortunately, I have not yet run into this little problem.
Any experience with this or any advice? Any reliable zinc detection methods that you recommend for sorting purposes? (I do know that zinc is much harder than lead but have not yet experimented with a scratch test. I suspect that is the way to go but verification would be helpful.)
Now the problem. For casting purposes, you definitely do NOT want the lead contaminated by zinc. It causes all sorts of problems, generally resulting in the need to discard a batch of lead.
I am pretty sure that zinc has a significantly higher melting point than lead but am not sure how careful you need to be to separate out the zinc weights from the lead and, if one gets into the melting pot anyway, how obvious is it that it is not lead before it begins to melt into the lead? Fortunately, I have not yet run into this little problem.
Any experience with this or any advice? Any reliable zinc detection methods that you recommend for sorting purposes? (I do know that zinc is much harder than lead but have not yet experimented with a scratch test. I suspect that is the way to go but verification would be helpful.)