Best copper sheet alloy for forming on lathe

[Janderso]

I've been playing around with forming copper sheet.
The copper I am using doesn't respond the same as I've seen on Youtube videos.
I've read the C145 is leaded and has more sulfer which is best for machining.
But, I can't find it in sheet form.

Help please.

 

[piper184]

The only thing I know about copper is that it work hardens.
Have you tried to anneal it? Heat it to cherry red and let it air cool in calm air. Hopefully it will soften for you. If you have some smaller pieces you can do some experiments to see what works best.

Do you know for sure that it is C145?
How thick is the sheet you are working with?

 

[WobblyHand]

You may have to anneal the copper multiple times while forming. The YouTube guys often edit out the tedious, boring parts out of their videos.

If you figure out forming and spinning copper I'd like to know how it's done. It's part shrinking and stretching and it totally escapes me.

 

[Janderso]

Both you guys hit on my first concern. Yes, I heated/annealed several times.
Watching the many videos on Youtube, it seems the process of forming creates plenty of heat so it may stay in an annealed state during the process.??
What thickness is best also??

 

[Janderso]

Do you know for sure that it is C145?

I bought some copper sheets from McMaster several years ago. Not sure what it is.
110 seems to be pretty standard? Or was it 101?

 

[WobblyHand]

You have to heat copper pretty warm to anneal it as I recall. Don't know that forming ever gets to that temperature. Think the forming is simply work hardening the piece. More annealing would be my recommendation.

 

[ChazzC]

Quinn has a number of detailed videos showing forming heads and tube sheets for a boiler. Lots of annealing in between (and during) operations:

https://youtube.com/playlist?list=PLY67-4BrEae8_HpGxaO1k3Wt_4oESh1hR&si=tzAk50My95CemB2y


Quinn partnered with Ron Covell on a copper water tank; he does things with sheet metal that will blow your mind:

 

[Asm109]

Save yourself time. Quench in cold water after annealing red hot. Quenching does NOT cause a hardening reaction like steel.

 

[ChazzC]

Save yourself time. Quench in cold water after annealing red hot. Quenching does NOT cause a hardening reaction like steel.

But it can buckle parts creating more work to get back to pre-quench shape & dimensions. When I made sterling jewelry this wasn’t much of a problem, but small pieces and thin cross sections.

 

[Janderso]

But it can buckle parts creating more work to get back to pre-quench shape & dimensions

Yes, I found that to be true.