zinc contamination

[luober]

After reading so many posts about zinc contamination in lead, how can you tell if you have zinc in any ingots that you buy? Is there a chemical that they can be tested with to show if they contain zinc? Does zinc contamination make the lead unusable for bullet casting?

[rancher1913]

yes there is a test and it can be found in many threads already on here. you can use the little search bar just below your sign in and it will answer almost every question you could ask about casting boolits. sorry if this comes across as not friendly but I am guessing most newbies don't know about the search function and I am really just trying to get the info out there. just type in major words or phrases like "test for zinc" and it will give you hundreds of threads about testing for zinc and how much is ok or even how to remove it from lead.

the short answer is acid, it will react with zinc and not lead, the stronger the reaction the worse the contamination.

[NyFirefighter357]

Up to 2% Zn contamination has been workable. Muriatic acid test.
http://castboolits.gunloads.com/show...-Test-for-Zinc
http://castboolits.gunloads.com/show...zinc-in-ingots
http://castboolits.gunloads.com/show...hp?171383-Zinc

[JonB_in_Glencoe]

If you have serious zinc contaminated ingots, they will look galvanized, like I posted in this thread.
http://castboolits.gunloads.com/show...ing&highlight=

I did an experiment casting with 1% Zinc, to find out about hardness. I didn't have any cast-ability problems, although I needed to set the alloy temperature hotter and I surely did get the noticeable and troublesome Oatmeal dross buildup.
(test starts on post #6)
http://www.artfulbullet.com/index.ph...let-alloy.589/