Getting copper clean

[doubletop]

I'm using a citric acid pickle bath but I have realized that to speed up the the cleaning process anneal the pieces first. Not because they need annealing but they get cleaner way quicker. Today I was busy cleaning off the engineers blue from the end plates I am making and after a few minutes thought "sod this" and took them over to the hearth, gave them a blast from the torch, cherry red, quenched and threw them in the pickle. Marking blue gone.

Then I made some 15mm tubes for the boiler. These were old plumbing pipe with that dark brown patina. "OK lets try this again". blast with the torch, quench and into the pickle.

See this pic.

The main boiler barrel and the larger tube haven't seen heat since whenever, but I've had then in the pickle for weeks, OK there's has been some marking blue on them and I've used wet/dry to clean them. The 7 smaller cross tubes are old copper that have been in the pickle about 2 hours, no blue, no wet/dry and no heat. Conclusion, the quick way to get copper clean is heat it to cherry red (annealing) and then into the pickle (quenching in water may be unnecessary)


If you've got an acid pickle bath don't do this.

Pete

 

[Kermit]

I was reading on another site about a Hydrogen peroxide and vinegar pickle that is supposed to remove the red(cupurous) oxide.

Seems an even ratio mix of distilled water, regular white vinegar and drug store H2O2(3%) will turn the oxide to a muddy brown black. Probably adding oxygen and creating the black colored cupric oxide. Agitate the part in the mix for 2-5 minutes as bubbles of gas are formed its surface. When the fizzing stops and the part has turned brown rinse under running water while scrubbing with a toothbrush and the copper should be back to its shiny self.

All on a Jewelry making forum I believe it was, damn this bad memory, :-\
Kermit