kevingambrell

Hi
just thought id pass this on.

had a bugger of a job today machining a lump of annealed copper bar. Bit like trying to machine toffee every cut the copper grabbed or plasticised on the tool.

After a lot of swearing i remembered a tip I picked up from my father. milk yup house hold tea addative type milk. filled a jam jar with moo juice and applied using a paint brush worked a treat. no more grabbing and a half way decent cut.

cheers kevin

P/s tallow works reasonably well but is getting harder to find.

Bunkerbarge

Low fat or semi-skimmed?

I guess the fat content has something to do with it!!

Interesting tip though, I have had a couple of attempts at cutting copper in the past on the lathe and given up.

__________________

“Dirty British coaster with a salt-caked smoke stack, Butting through the Channel in the mad March days"

kevingambrell

Hi Richard
My thinking is as you say the fat. Most important thing with copper is a negative rake on the tool and no chip breaker. Theres a common mis-conception that negative rake shows as a tool the slopes down, its not a negative rake lays flat to the center line of the work and therefore the center height of the lathe.

That all said and done coppers a pain in the backside to machine.

Cheers kevin