Hey guys;
We are not talking about wielding the metal here, but heat being applied more indirectly to the firewall, which will cause a gentler rise in temperature. I am not aware that zinc will undergo sublimation in this case, I think it will first melt and run off, but I don't know. That is what I will be testing. After the fire, will I have a bowl of zinc runoff, or nothing but zinc vapor? This should be a good determination. If I don’t' see zinc in the bowl, I won't be using this stuff anymore I my planes !!!!! (which so far has been on all my planes, as I recall).
Important stuff guys !!!!
p.s. There should be nothing under the cowling that can burn, if at all possible. Use metal and silicone lines, and when in doubt, try to burn the materials with a lighter, if it stops burning a couple of seconds after removing direct flames, it won’t sustain ignition by itself, and that’s a good thing.
Roger