Working Copper

[Matthew N. Masail]

I've got some pure copper bar stock for making the screw caps for the wooden planes I plan to make. I plan to make them more or less like in the infill planes just less fancy. I know a copper nickle alloy would be better as the pure copper is quite soft but that's what
I can get for free and it's 10mm thick so it should be stiff enough, but correct me if I'm wrong. I'll like recommendation for some mill files that will allow me to work this stuff efficiently, recommendations for coping saw blades would also be nice, and if you think this is a bad idea
for any reason please voice your opinion!

[george wilson]

I HATE working with copper,even turning it in a lathe. It is snarly,grabby,and generally not pleasant to work with. It will probably pin up your files pretty quickly,so use coarse files as much as possible,and rub them full of chalk to avoid suddenly getting a deep scratch on a surface you thought was nearly finished. Some machinists like to use oil on files. It may help the copper to not pin up your files also. Experiment with the 2 and see which works best for you.

Wrought iron can be bad stuff to file also. At least the old wrought iron we could get in Williamsburg,recovered from old demolished bridges,old fences,and the like. I have filed on old shotgun barrels made of wrought iron,and found it to be much nicer to work. More "dry" feeling. I think the problem with the wrought iron was that it was a low grade iron,full of silicon,and made for outdoor applications as it rusts more slowly than mild steel.

[David Keller NC]

One other comment - You will need to determine whether the copper is hard or not. Copper has the property of work-hardening, though that's typically only an issue with hammered work like repouse. Copper has a weird property, or at least a weird property compared to steel, in that to soften it, you heat it red hot then quench it. Doing that to steel will make it very hard indeed.

While "free" is always good, I'd consider how much work you're going to put into this project. Viewed in these terms, a small bar of 260 cartridge brass is pretty cheap, and the result will be much nicer.

[Matthew N. Masail]

thanks...I'll try see if I can get brass... if not, I'll try the oil and stuff. this is pure copper from high voltage electrical construction.

[Jonathan McCullough]

Funny you should mention . . . Copper used for HV applications can get crumbly after a long time. I don't know if it's oxidation, or some variety of hot/cold cycle work hardening, but copper components in old electronics can get brittle and clumpy.

[Matthew N. Masail]

I've seen many old HV boards that we took apart and reused the copper, never seemed brittle and bent well, so I'm not expecting problems like that. it's oxidation it a reddish orange patina - freshly cut it's a lovely pink-peach color. I've seem brittle looking pieces in really old circuit breakers, but the stuff I have is top quality, used for the main feed.