try vinegar and baking soda... it works pretty well, otherwise, I'd go get some Brasso, or some Contact Cleaner... since it won't leave a non-conductive residue

 

tried vinigar, didnt work. tried some mild acid, didnt work. tried the muric acide today, 31%, did nothing either.

 

the chemical reaction of baking soda and vinegar works well. mix the 2 on the copper

 

well muraitic is about the strongest you will find easily... so I guess you are ****ed... Id try adding some peroxide and failling that I'd sandblast the parts....

 

can i see a pic of what you are cleannig

 

sand blast it or have it glass beaded

 

i would say a lacker was painted on it if that has not worked so sand blast it or have it glass beaded

 

im cleaning a 2 inch peace of 1/0 gauge wire

 

How badly corroded is this and how much effort are you putting into cleaning it? Don't expect results in 10 seconds of applying a product.

I know you SPL guys figure all the fancy fuseholders and crap that us SQ guys like to use in our clean installs are just a waste of money, but perhaps protecting copper from the elements might save you this aggravation next time around. Maybe the wire was protected and still corroded. I've had that happen on factory wiring.

 

Try clr, makes your bathroom shine.