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Need help to plate pot metal!

I operate a decorative chrome shop working mainly with car restoration parts and a lot of them are pot metal. At this time I copper strike, followed by acid copper, buff and then nickel plate. Blistering in the pitted areas is usually a problem. Any ideas to eliminate this problem would be appreciated.

Lowell Beaman
- Yuma, Colorado, USA
2000

If you are stripping the part to base metal and the blister in the pitted areas, look at your cleaning (assuming you are grinding/polishing before plating). You probably are getting trapped compound in the pits. Be sure you are using a cleaner which is correct for the compound you are using. Also, use a wetting agent/additive in your acid pickle. If you are getting blistering and do not strip the parts, try using 15 to 25% by volume fluoboric acid as a pickle - the pot metal may contain lead. Lead is soluble in fluoboric acid but not in hydrochloric or sulfuric.

Gene Packman
- NJ
2000