DEPLATING POT METAL

[pickleboy]

i need help please. i am restoring some old gas pump parts for a friend and he wants them polished. the problem is they are chrome or nickle plated. the plating is in sad shape (bubbling). is there a way to remove the plating chemically without hurting the base metal (potmetal/alum ?). i know i can sand or sandblast but that makes twice the work for the polishing. i have seen a great wealth of experience on this forum so i am hopeful there is a easy remedy. thanks in advance for the responses.

[fxstcguy98]

If it's potmetal, you don't want to strip in chemicals potmetal reacts badly with acids. Because of the "bubbles" there will be pits in the potmetal that you will have to fill with solder (if they are deep and black, you may have to drill the black out). Clean, sandblast, rinse and strike nickle immediatly. Then acid copper and fill the pits with solder sand buff and plate as normal. Potmetal is a nightmare, especially if it's really old. As far as alum, I don't know of any stripping method that doesn't attack the base metal other than blasting. I may be wrong on this one, if there is a way I would like to know it too. I'm tired of sanding and buffing the blast profile off. Good luck.
Darrin

[clydes]

ok this is what works for me . put the part in the chrome stripper for about 10 to 15 min with about 50 amps on it. this will take off the chrome and some nickel. the longer you leave it the more nickel it will remove check it often. then blasting is easy saves tons of time. its just my way of doing it so try it if you want. good luck( better to use a high ph than a low on pot metal)

[pickleboy]

Originally Posted by clydes

ok this is what works for me . put the part in the chrome stripper for about 10 to 15 min with about 50 amps on it. this will take off the chrome and some nickel. the longer you leave it the more nickel it will remove check it often. then blasting is easy saves tons of time. its just my way of doing it so try it if you want. good luck( better to use a high ph than a low on pot metal)

thanks for the reply but i am not doing any plating just polish work, so no power supply, etc. that is why i was curious about chemical stripping. also is there a way to tell for sure if the base is pot metal or aluminum?

[fxstcguy98]

Sorry pickleboy,
Since this is the plating pot metal forum, I assumed you were plating it. Put a drop of sulfuric(battery) acid or muratic(hyrochloric) acid on the bare metal, if it bubbles violently, it's potmetal. Are you going to remove all the nickle plate? I don't think potmetal will hold a shine without plating on it, it will turn black, maybe it could be zoop sealed.
Darrin