We are receiving mixed advice from the "experts" on whether to use an ablative or a modified expoxy system for bottom paint on our cruising boats. These boats, a Hans Christian 33T and a Tayana 42, stay in the water, in the tropics, for years at a time. Last time they were painted, a modified expoxy system was used. West Marine Advisor recommends modified expoxy for cruising boats. Yet, two highly experienced captains/boat owners here insist ablative is the way to go. We would appreciate any additional word on this.

Thanks,
Doug

Doug, I think there's lots of opportunity for confusion on this (I surely have some...) since it's not only a function of type of paint but also the specific poisons used. Folks leaving Trinidad with a fresh ablative job rave about the results...but then, they are moving their boats and the yards down there use Jotun and Sea Hawk products, among others, that I'm told are not legal in the U.S. (or at least that was true in our case). Thus, it's hard to fair a curve between those user comments and what others in different locations might choose.

Also, I think any dive service or boat yard will be quick to point out that, with mod epoxy paints, the length of the paint's effectivenss is immeasureably extended if the bottom is serviced regularly. I found a monthly dive in Florida summers and a bi-monthly dive in winters kept my Petit Trinidad paint job (only 2 coats, 3 at the waterline) 100% functional for 3.5 years...and that's in REAL warm, hospitable-to-growth water.

OTOH the ablatives are almost the opposite: clean the hull at all and the lifespan seems to be hurt rather than helped. If your boats are little used, it would seem as tho' you face a dilemma: servicing the paint would be helpful but not a wise routine with ablatives, yet an ablative paint on a boat unused for extended periods is going to have growth.

I think WM favors mod epoxy because cruising boats often end up needing to stretch their bottom jobs (lack of facilities, tight budgets, variety of growth organisms vs. using a paint that may only be regionally effective) and so some servicing of the paint ends up being required...which ablatives suffer from more than mod epoxies.

I'd be interested in what others have to say. We're wondering what to use this coming Spring now that we'll be seeing cold water rather than the warm FL/Caribbean stuff.

Jack

Jack: That was an excellent response. Very helpful. Thanks.

Doug

FWIW, One man's experience--I have used both the Micron CSC and Trinidad SR paints on power and sail since 1987 in Florida. The abalative is fine for a powerboat, especially if it doesn't just sit at the dock. The motion of the water at higher speeds keeps the paint fresh and the abalative keeps paint buildup down. Painting is best done annually, though thickness of paint when it is applied is directly coorelated to life.
For slower sailboats, I have had much better luck with the Trinidad SR. With monthly scrubbing it lasts longer--I have 2.5 years on the current paint and am ready for hauling now.
Practical Sailor has done several studies over the years, both in Connecticut and more recently in Florida. While that is also just one sample, in just one very local marine environment, the test does provide another sample point.
Again, FWIW, on a sailboat in the tropics, my current preference in the US is the Trinidad SR, and it was hard to turn me from the Micron CSC. I would suggest you would have a better experience than with an abalative.
BTW, the Micron (and perhaps other abalatives) have more stringent application rules--both min and max times between coats, etc. Yards in Florida typically charge quite a bit more to apply Micron. If you do it yourself, you have to be more careful on the timing.

It's like asking what is the best varnish?

We use Interlux's ULTRA with teflon & biocide, which is a hard bottom paint. It's much easier to maintain and isn't a misserable mess in the yard. In colder PNW waters we get multiple years (3+) out of it with NO cleaning, just good old fashioned sailing cleans off any green gunk.

I'm not sure why anyone would use abalative. Even when we lived in Singapore (1 degree North), with heavy growth, friends reported good results with hard antifoulant paints. But I didn't get the brand name from them.

Has anyone heard about using tetracycline? It is an antibiotic sold by feed stores for barnyard animals. It is nontoxic but apparently can keep your bottom free of grass and barnacles for years. It is simply mixed in with whatever bottom paint you are using. Starbrite sells it in West Marine under the name "Compound X" for about 4 times the cost of the feed stores.