5 Aug
2007
5 Aug
'07
11:15 a.m.
They're
made of copper, but they're also plated with iron, and once that
plating is gone the copper doesn't last -- it gets pitted, etc. On really
old stuff I used to file tips, but not any more...
Back in the old days, we used to coat the copper tips with silver
(hard) solder (56% silver) to extend the life. But you need a torch
to do that--silver solder melts at about 1100F and requires a special
flux.