More Fire Bricks

That's pretty much it, except that quenching aluminum or copper alloys is not required to make it softer, the heat takes care of that. Quenching does limit the time that the metal is exposed to the higher temperatures, though, and thus reduces the oxidation that is faster at elevated temperatures.

Once softened, there are only some of the aluminum alloys that can be hardened by heat treatment while the others, as well as many of the copper alloys, require work hardening to harden up at all.

Cheers Trevor Jones

The point is that you don't need bright orange heat to anneal ally, the temperature of charred household block soap works for me, and therefore a hearth full of SH blocks would maybe be quite a good thing. But OTOH, quite counterproductive if used as a brazing hearth.

Hoo!

Yes, I did eventually realise you meant that :-)