Two Letters Re: Do it Yourself Low Temperature Casting

J.W.G. has a great idea with the zinc pennies. When I need to fabricate a part I usually look under the hood of a junked car for something to melt, many easily-cast metals are under the hood requiring only a blown charcoal forge and covered dry steel pot. The Multimachine web site pointed me to a great source of high very quality casting aluminum: the overhead cam cylinder head from a motor that does not use separate cam bushings. Just ask a mechanic that you trust. Here in Israel there are also easily found junked brass plumbing fittings often found around, or for small jobs the coinage here is mostly hard brass too. A good eye and a few junk piles make great seed stock for easily cast metal projects. Anyone interested in going it alone even if they only needs a sub-scale machine should browse the multimachine archives for many tricks on precision improvised machine shop work, low temperature forging, and tools. – David in Israel, SurvivalBlog’s Israel Correspondent

Remind your readers to become informed with the danger of melting Zinc. The fumes given off are very poisonous. – Wayne R.

JWR Replies: Actually, low temperature casting of zinc and zinc-copper alloys does not release zinc-oxide fumes. (Unlike welding zinc-galvanized steel, which uses very high temperatures–above the boiling point of molten zinc.) See this article from The Periodic Table web site, for details. This is not to say that you shouldn’t use all the normal casting safety measures. For example, casting should be done only outdoors or in a well-ventilated open-sided shop. Don’t over-heat zinc alloys unnecessarily, and watch for any telltale white zinc oxide smoke. Always keep in mind that heavy metal poisoning is cumulative, insidious, and essentially irreversible! Avoid repeated exposure to any alloys that include lead. If in doubt, don’t melt it!

FWIW, I have been an ammunition hand loader since I was 15 years old, but I have never castany bullets. This was a conscious decision, after doing some research on lead toxicity and accumulation in the human body. In my estimation the risk of exposure to lead far outweighs the benefits derived from lower projectile costs