> In a previous post you said the Cu could be hardened by heating in the water > tank. I would like more info on this. Walt, You're confused, no doubt, by the fact that copper is _softened_ by heating. Small wonder, you're right. But the heat of boiling water is not enough to anneal (soften) the metal; is must be heated consideraly hotter to soften it. What I didn't make completely clear before is that the increasing pressure inside the tank, from the rising temperature of the gas inside, will work-harden the copper. Just as in a silver-soldered boiler, the rising pressure stresses the copper, and this hardens it just as hammering, rolling, etc. would do. So, no bloated toads. :-) -vance-
