Hi gang,
I have some thick cables that need to be properly jointed. They're good for 300 Amps so pretty thick. Trouble is they were stored in a damp environmen t and have that black coating on the copper. This is the form of Copper Oxi de IIRC which forms when there's a limited supply of oxygen to the metal, a s opposed to the green oxidisation you get on copper roofs and whatnot. So the question is, what commonly available chemical will attack the black oxi de without damaging the copper underneath it? (Need to get it off before I solder the joints, obviously.)
cheers.