Best non toxic anti-fouling for PNW?

Apr 25, 2024
111
Fuji 32 Bellingham
It has been pointed out that, for paint to be anti-fouling, it generally does this through being hostile to biology. I recall reading about some coatings that seek to be resistant by providing a texture that makes it difficult for organisms to attach themselves, but I think these are largely experimental still. They are certainly not widely used, yet.

But ... I learned something recently. When we purchased our boat, it was moored in Tacoma. At the survey haulout, there was NO antifouling paint whatsoever. It was covered with football-sized clusters of mussels. They cleaned it up but did not bottom paint, at that time. It then sat about 3 weeks before we got to look at her again. By that time, it had a substantial beard coating everything below the waterline. We gave her a quick scrub and took her out for a sail and most of the visible gunk was gone except for some patchy surface slime. But, within 2-3 days, the beard was back.

I mention this because this hasn't been our experience in our home port of Bellingham. I was amazed at how fast the growth happened in Tacoma. We could leave the same boat in Bellingham for several weeks and just get a little bit of beard right at the waterline and some slime starting to coat surfaces. The water must be colder? In general, we found the water down south quite dirty, by comparison.

In other words, there are some regional differences, even within the PNW.

We paid particular attention to this because we considered not applying bottom paint at all until this fall, since the boat will be sailed at least 3-4 days a week, and will move around all summer. Based on our trip up from Tacoma, this week, we think we could skip bottom paint entirely, so long as we keep sailing her regularly. (As it happens, we have to haul out for some other reasons, so we are bottom painting next week, but I don't think we really need to until this fall when we will sail less consistently.)

I know this doesn't really answer your question, but thought I'd share our recent experiences, as they seemed related to the topic.
 
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Jan 11, 2014
12,117
Sabre 362 113 Fair Haven, NY
I mention this because this hasn't been our experience in our home port of Bellingham. I was amazed at how fast the growth happened in Tacoma. We could leave the same boat in Bellingham for several weeks and just get a little bit of beard right at the waterline and some slime starting to coat surfaces. The water must be colder? In general, we found the water down south quite dirty, by comparison.
Water temperature and nutrients in the water make a huge difference. We were once in St Augustine FL and went from a clean bottom to one so fouled with growth we could only motor at 1.5 knots in just 3 weeks.
 
Apr 8, 2010
2,022
Ericson Yachts Olson 34 28400 Portland OR
Making hulls too slick for must stuff to stick.... is not a new idea. We sail in fresh water and lots of boats, racing and cruising, have used various versions of "VC 17" since the early 80's.
 
Dec 28, 2015
1,883
Laser, Hunter H30 Cherubini Tacoma
It has been pointed out that, for paint to be anti-fouling, it generally does this through being hostile to biology. I recall reading about some coatings that seek to be resistant by providing a texture that makes it difficult for organisms to attach themselves, but I think these are largely experimental still. They are certainly not widely used, yet.

But ... I learned something recently. When we purchased our boat, it was moored in Tacoma. At the survey haulout, there was NO antifouling paint whatsoever. It was covered with football-sized clusters of mussels. They cleaned it up but did not bottom paint, at that time. It then sat about 3 weeks before we got to look at her again. By that time, it had a substantial beard coating everything below the waterline. We gave her a quick scrub and took her out for a sail and most of the visible gunk was gone except for some patchy surface slime. But, within 2-3 days, the beard was back.

I mention this because this hasn't been our experience in our home port of Bellingham. I was amazed at how fast the growth happened in Tacoma. We could leave the same boat in Bellingham for several weeks and just get a little bit of beard right at the waterline and some slime starting to coat surfaces. The water must be colder? In general, we found the water down south quite dirty, by comparison.

In other words, there are some regional differences, even within the PNW.

We paid particular attention to this because we considered not applying bottom paint at all until this fall, since the boat will be sailed at least 3-4 days a week, and will move around all summer. Based on our trip up from Tacoma, this week, we think we could skip bottom paint entirely, so long as we keep sailing her regularly. (As it happens, we have to haul out for some other reasons, so we are bottom painting next week, but I don't think we really need to until this fall when we will sail less consistently.)

I know this doesn't really answer your question, but thought I'd share our recent experiences, as they seemed related to the topic.
I've been in Tacoma for the past 7 years and this last year has had noticeably faster growth. I use to dive on mine and clean it every 3-4 months and now I'm seeing growth in the sun areas within 4-5 weeks. I'm certain some of this can be caused by end of life bottom paint but everyone on my dock has had the same experience. Long stringy green growth on the water line that is a real pain to get off. I tend to use a stiff brush in place of my typical white scrubby.
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,004
CAL 35 Cruiser #21 moored EVERETT WA
A friend used a pvc pipe contraption he put together with some carpet on the end to give his hull and keel a scrub every week. It knocked off the scum and growth efficiently before each race.
 
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jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,004
CAL 35 Cruiser #21 moored EVERETT WA
when it come to anti fouling paint, "non-toxic" means "non-effective".
And that is ok if you are happy scrubbing and scraping your boat bottom on a regular basis. Or storing your boat out of the water when not in use.
 
Nov 22, 2011
1,215
Ericson 26-2 San Pedro, CA
Anybody who thinks that cleaning an unpainted boat bottom (no matter how frequently) is a substitute for anti fouling paint has never tried cleaning an unpainted boat bottom
My point was, why bother with painting a boat bottom with antifouling paint that does not actually prevent marine growth? IOW, I thought I was agreeing with what you said in post #26.

However, maybe you are saying that there *is* some advantage to painting the bottom with an ineffective "antifouling" paint vs. not bothering?
 
Feb 26, 2011
1,436
Achilles SD-130 Alameda, CA
My point was, why bother with painting a boat bottom with antifouling paint that does not actually prevent marine growth? IOW, I thought I was agreeing with what you said in post #26.

However, maybe you are saying that there *is* some advantage to painting the bottom with an ineffective "antifouling" paint vs. not bothering?
If you think anti fouling paint doesn't retard fouling growth, I suggest you go a few months without it
 
Nov 22, 2011
1,215
Ericson 26-2 San Pedro, CA
If you think anti fouling paint doesn't retard fouling growth, I suggest you go a few months without it
No, no, no!!! I think we are talking past each other here!

I *do* think that antifouling paint--the good stuff--actually works. This thread was about someone who wanted to find a non-toxic bottom paint. You pointed out-- quite correctly, I think-- that non-toxic bottom paint does not work. (Again, see your post #26.) You said specifically that such paint is "non-effective."

My point is that *IF* you are going to paint a bottom with "non-effective" bottom paint, why go to the trouble at all? Just leave it unpainted. I'm not saying one should do that!
 
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Apr 25, 2024
111
Fuji 32 Bellingham
My point is that *IF* you are going to paint a bottom with "non-effective" bottom paint, why go to the trouble at all? Just leave it unpainted. I'm not saying one should do that!
I understood your point.