White Smoke at over 2,000 RPM - Westerbeke 38B - Four

Oct 22, 2014
21,104
CAL 35 Cruiser #21 moored EVERETT WA
Oxalic acid is the primary agent. Same in Bar Keepers but stronger in FRS.

I’ve seen FRS used on stained fiberglass dinghy bottom. Let us know if it works.