Cold Galvanize

[MorganFab]

Does anyone have a opinion about using a cold galvanize for primer on a mild steel hull?

[JimCooper]

Works well, but only above the waterline outside and everywhere else. Evertime I expose or clean a piece of my boat I paint it with a zinc rich primer before the epoxy. Kills the rusting dead, wish we'd had it years ago would have saved a lot of chipping.

Cheers
Jim

[MorganFab]

Thanks for the info jim, i will put it to good use Alex......

[tazmann]

Hello Jim
Im building a steel sail boat and was considering cold galvanizing the whole thing inside and out before epoxy. Is there a problem doing it below the water line? I just started researching the idea and any info (pros-cons) would be appreciated.
Tom

[MikeJohns]

Zinc rich primers are the next best thing to hot zinc spraying. They will protect the surface very well.

Submerged metals should not be coated with sacrificial primers since under continual immersion any breach in the outer paint system will lead to the outer layers of paint disbonding following the zinc depletion. Use external anodes instead.

In the submerged areas use a high build surface tolerant epoxy directly over the prepared steel. Topsides decks and all the interior hull will benefit greatly from a zinc rich primer.