Copper sheet

[Parm]

ive got a copper sheet that is 1.8 mm thick. I want it alittle thinner for a project I want to try over the next few weeks. Can I heat this up and beat it down to around 0.8mm. It doesn't have to be perfect as the rustic effect will be quite good.

I've got a few decent hammers, a few planishing hammers, a big heavy anvil and an oven that can go to 950c

 

[mike 109444]

Think you will find copper works the opposite to steel as in working it softens it and heating and slow cooling hardens it IIR

 

[brightspark]

Think you will find copper works the opposite to steel as in working it softens it and heating and slow cooling hardens it IIR

if u are talking about copper heating softens it

 

[Digger6135]

Heating definately softens copper, hammer it and it work hardens, you then need to anneal it again to soften it, and then keep repeating the process.

Digger6135

 

[Parm]

Heating definately softens copper, hammer it and it work hardens, you then need to anneal it again to soften it, and then keep repeating the process.

Digger6135

Yep that's what I've discovered on the Interweb thus far tonight

 

[Parm]

So my crazy plan might just work then

 

[Digger6135]

It depends how big the sheet is, if you have access to a set of pyramid rolls, you could anneal it then roll it progresively, increasing the pressure with each pass, annealing frequently.

Digger6135

 

[MattF]

So my crazy plan might just work then

Can't see why not. Working copper, I usually anneal to dull/cherry red temperature, (if you're working in a well lit place, you'll note the surface becomes silvery grey in appearance at around the time the dull red temp is hit), then let it air cool. You can quench, but you have to be spot bollock with the temperature, I've found, whereas air cooling gives you a tad more leeway if you miss the exact mark slightly. Give a test corner or piece a few decent whacks and you should be getting somewhere close to your required thickness.

 

[Parm]

I want to end up with squares about 120mm. I'm thinking that if I cut 120mm squares from the 1.8mm sheet I can then anneal hammer etc until I get roughly the required thickness, trim back to 120mm, job done. I HOPE !

 

[Parm]

Can't see why not. Working copper, I usually anneal to dull/cherry red temperature, (if you're working in a well lit place, you'll note the surface becomes silvery grey in appearance at around the time the dull red temp is hit), then let it air cool. You can quench, but you have to be spot bollock with the temperature, I've found, whereas air cooling gives you a tad more leeway if you miss the exact mark slightly. Give a test corner or piece a few decent whacks and you should be getting somewhere close to your required thickness.

I should be able to get the temperature quite accurate as I have small industrial furnace type oven with quite precise temperature control

 

[MattF]

Annealing should be a breeze for you then. After doing that first square, I'd work out roughly what size square to cut for the next one. You'll be wasting copper no end cutting it full size and then trimming back afterwards. Going down to less than half thickness will spread it out quite a bit.

 

[Parm]

Annealing should be a breeze for you then. After doing that first square, I'd work out roughly what size square to cut for the next one. You'll be wasting copper no end cutting it full size and then trimming back afterwards. Going down to less than half thickness will spread it out quite a bit.

Good point

 

[penfold]

You'll die of old age hammering 1.8 down to 0.8; do yourself a favour and buy a piece the right thickness. If you must it won't be anything close to flat. Heat it to red and let it cool in air to anneal(you can quench in water but it seems to cause more oxidation).

 

[optima21]

yeah the amount of energy required for metal thinning can be pretty large. I can remember burning my hand on part coming out of power press, it was thinning a 1/4 spade terminal on an 12v car relay from 1.4mm down to 0.7mm (steel not copper). think they were using a 50 tonne press as the 30 tonne presses wouldn't look at it

 

[rtbcomp]

I normally quench copper washers - the boiling action of the water displaces scale. If you let it cool in the water it shouldn't oxidise.