In article ,
Chris Bacon writes:
Andrew Gabriel wrote:
"Doctor Drivel" writes:
First anneal it. Where the curve is to be heat the copper to cherry red
then quench in water.

your annealing process is for wrong metal. Copper is annealed at 700-800C
(can be done as low as just over 400C, but you have to hold it at that
temperature for a long time). There is no state change on cooling copper,
so quenching is not required -- you can cool it over as long a period as
you like. The annealing process for copper is reversed by flexing and
vibration, not by slow cooling.

I'm not sure about your terminology or where the last sentence
comes in, but heating to red hot and quenching is fine.

Didn't say it wasn't, just pointing out it isn't necessary to go
to those lengths. In particular, quenching is used to preserve
crystaline structures which would not normally exist at lower
temperatures, by super-cooling them into a preserved state.
There is no such cystaline state change with copper on cooling,
so it's pointless. With copper, the reverse process to annealing
is work-hardening, which is triggered by flexing and vibration.

For bending a large thick piece of copper, it should be reannealed
during the bending process, or bent at a temperature which is high
enough to keep annealing it throughout the process. This counteracts
the work hardening caused by the bending itself. One way this
used to be done with very large copper pipes was to fill them with
molten lead under pressure instead of sand, at a suitable temperature.

--
Andrew Gabriel