How to restore pewter finish damaged in dishwasher

A. Hi Cindy. You'll never see a shiny sponge because a spongey surface isn't a smooth polished surface. I suspect that the alkali in the dishwasher detergent turns the surface of pewter slightly spongey instead of smoothly polished. Thus, although the many different possible fixes use different chemistries, I think the real key is the mechanical polishing they do.

I think what I would do is get a soft buffing pad for a low powered battery-operated drill, and try a mild buffing/polishing compound like Mother's Aluminum & Magnesium Polish. I think steel wool by hand can eventually do the same thing but would be a hundred times more tiring.

Luck & Regards,

A. To polish pewter, boil linseed oil and mix it with rottenstone (can be purchased at your local hardware store, instead of linseed you can use sunflower oil too). Continue to add rottenstone to the oil until the mixture becomes thick. Let the mixture cool. In circular motions, rub the mixture into the pewter until you achieve the desired level of shine
https://newengland.com/today/living/home-repair-diy/how-to-polish-pewter/

Hope it helps and good luck!

A. Try to find some proprietary product, or you can use precipitated chalk (mixed with water to thick paste). If you can find it, you can use herb called horsetail (Ecquisetum arvense). It is very good for polishing pewter.