Trim body corrosion

[cymru]

The par tthat sits in the seawater all year round is now badly corroded but not leaking as far as I can tell. Is it possible to stabilise this, or is it just a case of waiting for the inevitable to happen? It was painted one year with antifouling paint for fiberglass, which I was told later didn't help.

 

[dingbat]

Re: Trim body corrosion

Painting them with anti-fouling bottom paint was the mistake. They make a special anit-fouling paint for out drives for a reason.
Bottom paint contains copper. Mix copper and aluminum together, add saltwater and you end up with exactly what you see there. The remains of a battery.
At this point, the only thing that will clean it up is to bead blast it off.