To anneal or not to Anneal, that is the question...

[Phil Patrick]

I plan to start on a new project in a week that part of which will involve me making a rather large (18") somewhat shallow bowl in copper or brass sheet in 16ga(0.60").
I've done alot of metal forming in sheet steel and aluminum form light to heavy gauge. In aluminum I've always annealed it. Having very limited time with copper, the question is;
Do I need to anneal it to work it? I believe yes, but I'll leave it to those with experience.
Two; if yes,, how?
As usual all info will be greatly appreciated!!!!!!!!

Thanks
Phil

[Jeff Mack]

I've dished some much smaller copper bowl shapes, and I did need to anneal. Copper work hardens slower than some other metals, but it still needs to be anealed if you are going to bend it very far. My project fit into my enameling kiln, so I used it to heat the piece, and quenched in water, then used warm jewelers pickle to clean off the scale.

I'm not sure I'd have a good plan for an object the size you are working. Maybe a big kiln, or bonfire?

[Phil Patrick]

About how hot would I get the material before I quench it?

[ThomasPowers]

I usually heat it till it glows slightly in a dark room

[bipolarandy]

heat it till it glows a dull red and hold it there for around 30 seconds. wait till the colour runs out of it and quench it in water. as soon as it feals hard under the hammer , anneal again, normaly 30-50 hammer blows depending on what it is.

[Phil Patrick]

Thanks everybody!!

[sfDuck]

Thanks that was my question too............Duck

[ladysmith]

Andy has it right. Although if it's something I can work hot, I don't bother quenching. Heating to a dull red is what softens it. Quenching cools it enough to handle.

This pendant was made with copper ground wire and totally hot forged. Just remember when hot forging to watch your piece carefully and not let it get above a dull red. Copper melts easily.

Also when hammering, use a practice piece first to get an idea of when it work hardens. It's not quite as easy to tell as iron. If you continue hammering after it's work hardened it'll become very brittle and will chip, split, and crack.