Which Bottom paint for fiberglass sailing boats

[Zathur]

Hi all

I'm sure you guys talked about this stuff over the years but also things change over the years, so lets just update folks,
here, just write the name/brand of the paint, do not explain why it's best, it's best because it's your experience, we are looking for your personal experience let's see how many people will name same names.

[fstbttms]

Nothing has changed in decades. The best anti fouling paints are still:

Hard- Petit Trinidad
Ablative- Interlux Micron 66

[BillKny]

Originally Posted by fstbttms

Nothing has changed in decades. The best anti fouling paints are still:

Hard- Petit Trinidad
Ablative- Interlux Micron 66

Matt knows more about bottom paint than just about anybody I know, but I have to add a caveat to his recommendations.

When I had a boat in SF Bay Micron 66 was my go-to paint. I now sail from the Caribbean to the Canadian Maritimes, and sometimes find myself for extended times in water far more fresh than salt. Micron 66 is specifically counter indicated by the manufacturer for exposure to freshwater. The binder dissolves far too fast in freshwater.

Continuing with ablative paint, we have been using Seahawk Biocop with excellent results across a very wide range of conditions.

[fstbttms]

Originally Posted by BillKny

Matt knows more about bottom paint than just about anybody I know, but I have to add a caveat to his recommendations.

When I had a boat in SF Bay Micron 66 was my go-to paint. I now sail from the Caribbean to the Canadian Maritimes, and sometimes find myself for extended times in water far more fresh than salt. Micron 66 is specifically counter indicated by the manufacturer for exposure to freshwater. The binder dissolves far too fast in freshwater.

Continuing with ablative paint, we have been using Seahawk Biocop with excellent results across a very wide range of conditions.

I appreciate the kind words but the OP did ask for our own personal experiences, which is what I offered. But as in all things, YMMV.

BTW- I wouldn't wish any Sea Hawk anti fouling paint on an enemy. That you are pleased with yours is evidence that what works poorly in one region may be a good performer in another.

[Greg Mason]

Micron CSC.

[Jammer]

I use Micron Extra. @Fstbttms, I am curious about your experience with it. I understand that has copper content similar to Micron 66 but a different binder and the zinc pyrithione is replaced by butyl-N-cyclopropyl-6-(methylthio)-1,3,5-triazine (trade name "biolux"). It is suitable for fresh and salt water. It is unclear to me whether it is suitable for use when the hull will be scrubbed by a diver. As with any ablative paint there would be some loss of thickness with each scrubbing.

Interlux Ultra is the same biocides as Micron Extra but in a nonablative binder.


I am also curious as to how a boat owner should choose between hard and ablative paints. The advantage of ablative paints is that they don't accumulate and are easy to maintain by recoating with minimal sanding. What is the advantage of hard paints?

[fstbttms]

Originally Posted by Jammer

I use Micron Extra. @Fstbttms, I am curious about your experience with it.

Not a fan. Too easily scrubbed off the hull.

Originally Posted by Jammer

It is unclear to me whether it is suitable for use when the hull will be scrubbed by a diver. As with any ablative paint there would be some loss of thickness with each scrubbing.

True to a point but like any anti fouling paint, ablatives still need regular cleaning.

Originally Posted by Jammer

What is the advantage of hard paints?

The primary advantage is a longer lifespan.

[EngineerRetired]

This has to be the longest discussed topic since fiberglass

[Stewie12]

Ask a few local boat owners what they use. Different waters, hot cold etc can make or break an antifouling. Your local chandler would also be of help.

[arcticmonkey]

"I know a guy" his main choice of bottom paint was latex... old wooden boat.. His reasoning was.. ya gotta pull it out once a a year anyway... why spend hundreds when your buddies have paint in their sheds...

[sailcrazy]

We've been using Micron 66 for the past 12 years....sailing from Asia, to the Medd, and now the Caribb. But this off season(hurricane season) our hull has started showing "scaling" at the waterline and at a few other places. Interlux called it "corn flaking", and said it is due to fresh and/or brackish water exposure.....a local boat yard contractor in Puerto Rico claimed it could also be the result of a rain or fresh-water bath between coats?? At any rate, if you're sailing in fresh or brackish waters, Micron 66 is not for you! We're still trying to resolve the issue-short of completely stripping the hull. We've been in the NE Caribb for the past 7 seasons, hauled every hurricane season here in Puerto Rico, and have never seen this before......but there it is now! Local boatyard ctrs are recommending Seahawk Islands 77, FWIW.

[chrisr]

since we started cruising we've been using altex # 5 and been pretty happy with it

however last slipping we used altex # 5 plus. improvement so far seems significant and worth the extra cost, but jury is still out for another year or so...

cheers,

[TideTime]

Definitely Pettit Trinidad for a hard bottom paint; costly but worth the price.

[stormalong]

Originally Posted by TideTime

Definitely Pettit Trinidad for a hard bottom paint; costly but worth the price.

I read that Trinidad had been discontinued due to it's active ingredient being banned. Can anyone confirm that?

I have been using Trinidad forever and was disappointed to read that.

[fstbttms]

Originally Posted by stormalong

I read that Trinidad had been discontinued due to it's active ingredient being banned. Can anyone confirm that?

I have been using Trinidad forever and was disappointed to read that.

There are four or five flavors of Trinidad. Only one of them (Trinidad SR) has been discontinued due to availability issues with its anti slime ingredient, Irgarol. The others are still available.