Painting over Sea Hawk Biotin

[nmccubbin]

We painted 2 coats of Seahawk Biotin over fresh sandblasted epoxy primer on our aluminium bottom last year. We were in Grenada where Biotin is legal

The antifouling performance of Sea Hawk was disappointing. Hundreds of tiny barnacles formed withing a few weeks. They were easy to scrape off with plastic scrapers, and swimming in the Caribbean is not too tough to take

Milvina has been on the hard in Curacao for the summer and we plan to anti-foul with Interlux Pacifica Plus next month.
Interlux recommends 3 coats Interlux Primacon as a "tie coat" over the Biotin.
I get the feeling that this is to prevent tin bleed through. I do not care about that, since lots of boats around us have tin paint.

Key question is whether the Pacifica Plus will stick to Biotin, or perhaps after one coat of Primacon

Comments from those with experience wold be welcome

[Nicholson58]

Originally Posted by nmccubbin

We painted 2 coats of Seahawk Biotin over fresh sandblasted epoxy primer on our aluminium bottom last year. We were in Grenada where Biotin is legal

The antifouling performance of Sea Hawk was disappointing. Hundreds of tiny barnacles formed withing a few weeks. They were easy to scrape off with plastic scrapers, and swimming in the Caribbean is not too tough to take

Milvina has been on the hard in Curacao for the summer and we plan to anti-foul with Interlux Pacifica Plus next month.
Interlux recommends 3 coats Interlux Primacon as a "tie coat" over the Biotin.
I get the feeling that this is to prevent tin bleed through. I do not care about that, since lots of boats around us have tin paint.

Key question is whether the Pacifica Plus will stick to Biotin, or perhaps after one coat of Primacon

Comments from those with experience wold be welcome

Not likely to get a technicality correct answer here. I have found the manufacturers of paint to be very truthful and helpful. Try on line or phone. The best assistance ever was at a boat show where the reps were there in person. Their advice did not agree with what was on the can.

[fstbttms]

Tin-based anti fouling paint (the use of which is morally and environmentally reprehensible, IMHO) is incompatible with any other type of anti fouling paint. Why you would consider disregarding the manufacturer's recommendations for overcoating the Biotin is beyond comprehension and a likely recipe for a failed bottom job.