February 26, 201313 yr I bought some copper flat bar from the local scrap yard, it looks like it might be a electrical bus bar of some kind. I intend this copper, as thick as it is, to be used for knife fittings. however it has a yellowish coating(or more accuratley a plating) on it. this coating burns off easily as i anneal it so as to make cutting and shaping easier. anyone have a clue as to what this yellow coating is.
February 26, 201313 yr photos may help, count be as simple as yellow77 lube, or it could be a toxic substance
March 1, 201313 yr If it was cadmium like Mark said and you get over exposed to the fumes when you burn it off, you will pass out, when you wake up a few minutes later you will feel fine until you drop dead 12 to 24 hours later. You scratch and sniff chemists need to learn to ask first and act later when you have the proper information or as I have said before, take out a big life insurance policy and name me the beneficiary.
March 25, 201313 yr I had some squarish cross section copper wire from an old electrical somethingorother and I soaked it in acetone and it cut that yellowish crud right off. I think it was some kind of varnish to keep the copper from corroding during the manufacturing process. Later on instead of using acetone I would just cut off what wire I needed and heat it up with a torch since it needed annealing anyway, this I would do outside and then pickle it to remove all the crud and leave me with bright but dull copper wire to work with. Don't burn the yellowish crud off inside it does smell a bit like burnt paint and stand up wind.
March 26, 201313 yr Yup could be a varnish or could be cadmium, not enough info supplied. You should be able to tell easily though Cadmium is plated on as a metal. You can scratch it with an awl. The varnish is a translucent to transparent coating that is fairly soft (or hard and brittle from age)
April 1, 201313 yr Author is is a plated coating of some sort, i was hoping someone with more experience than i would know what it might be. it is a goldish yellow coating(it almost looks like brass), i will try to get a picture tomarrow. as for the scratch and sniff chemist...i never said it, but I did avoid the fumes. I may not know what the coating is, but that never meant i was breathing it. i burnt it off is an open area
April 19, 201313 yr You might contact an electrical supplier and ask. I don't know about gold colored coatings but bus bars often contain byrillium for strength making the dust or smoke toxic in the extreme. Almost as bad as cadmium, bad BAD. Cadmium has no odor so you wouldn't know if you were getting dosed and it has long term effects, say, cancer. Frosty The Lucky.
April 19, 201313 yr I have some square copper windings, about 3/8", that were covered with a thin layer of fiberglass and I put them through the fire. It need annealed anyway so I brought them up to a dull red to anneal and the fiberglass just curled up and fell off in little globs. Then I could forge it out into flatter pieces. It sure took a toll on my poor back but it made some nice bracelets.
September 24, 20241 yr Good morning guys, i need some help with copper electroplating cyanide base. After plating some screws in barrel some of the screws turned yellow in color while other in red copper.. How did I get the yellowish copper appearance?
October 22, 20241 yr Heres a great way to introduce yourself! https://www.iforgeiron.com/forum/22-introduce-yourself/
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