Saildrive antifouling

[CarlF]

Any updates on successful saildrive antifouling?

I've seen the following:

Propspeed : Very effective but very expensive and best to coat every year

Spray on cans (various) - less than a year - if that.

Trilux over primer - good but less than a year

Pettit Ultimate Eco over primer - lasted two years (but only one report)

Anything else that worked?

[Captain Bill]

I used Pettit Ultima Eco and it is about done after three years, though since covid It did not get much use last year. I did use 6 coats on two sail drives under the theory that it doesn't do much good sitting in a can. The first time I used it I used three coats and got two years out of it. There was still some left but instead of sanding down to bare metal I used Pettit Tie Coat Primer between the old and new paint. That primer is red-orange so it's really obvious when the ablative Ultima Eco starts to get thin.



I didn't have too bad of luck with Pettit Vivid on my original sail drives. I had a coat of Epoxy primer under it and never had any corrosion issues. The Vivid would last about two years. I did try a couple of the spray can types and they never worked. One required a coat of zinc chromate primer on the aluminum. The stuff peeled off anyway and the only place that didn't grow barnacles was where the zinc chromate was exposed. It was a lot better anti-foul than the crap in the cans.