copychrome

[lloyd]

I have some new u-bolt nuts I want to copychrome. They have a black coating on them, I don't know what the coating is. I put them in sulphuric acid and they fizzed a little bit, but there is still a little black on them. I guess my question is, will there be a problem putting them in the copychrome, I don't want to ruin the solution? Of cource the outsides will be polished, but the threads will still have the black. Thanks for any help in advance. lloyd

[mcaswell]

It's probably a black oxide coating. It needs to come off before plating. Use muriatic acid. See http://www.caswellplating.com/bbs/viewtopic.php?t=643

[lloyd]

THANKS CASWELL

Thanks a bunch. I will give the muratic a try. lloyd