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Closet Powerboater
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Discussion Starter · #1 ·
Without getting into specialty types, there seem to be 2 main categories of paint:

1. Hard paint (I believe they are also called modified epoxy) which stay in place and leech copper to the surface to offend growth.
2. Ablatives, which allow critters to stick to them, but then peel away when scrubbed or when underway to allow the critters to fall off.

I've only ever used what came with the boat. The first boat was wood, and I was told that the hard paints couldn't be used (due to flexing of the hull?) and used ablatives. The current boat came with hard paint, so I continued that. I've had great success with both, but then again, I live in a low-growth area so that's probably the main reason for my success.

What are the pros and cons and applications for each? Is one better in the short or long term, or is one better than the other for frequent storage on the hard? How do you choose between the 2 broad categories?

MedSailor
 

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Your descriptions of how a modified epoxy paint works is accurate. You're on the right track with your description of how an ablative works, but not quite spot-on. Ablatives work primarily because the surface of the paint "ablates", much like a bar of soap. As the paint moves through the water, the surface layer slowly wears away, exposing fresh biocide. This is not to say that no biocide is released while the boat is at rest- it is. But both types of paint are prone to some fouling and need to be cleaned periodically. Ablatives are no better at retarding this fouling (in most instances) than any other kind of paint.

Some pros and cons:

Hard paint pros- Durable, typically longer lived than ablatives, typically higher copper content. Cons- Successive layers of paint will at some point have to be removed, cannot be exposed to air for any length of time, limited color assortment.

Ablative pros- Can withstand exposure to air, will not build up like hard paints, wide color assortment. Cons- not particularly durable, low copper content, in-water cleaning restricted in some regions.
 

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Speaking as someone who once scraped & sanded decades of buildup off a 43' and who recently completed scraping & sanding a 30' boat to the gel-coat, I plan on never using anything but ablatives in future.

For any reason. :)

If in-water scrubbing becomes illegal, I'll willingly pay for a 1/2 lift to scrub it off rather than face that back breaking job ever again.
 
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Your descriptions of how a modified epoxy paint works is accurate. You're on the right track with your description of how an ablative works, but not quite spot-on. Ablatives work primarily because the surface of the paint "ablates", much like a bar of soap. As the paint moves through the water, the surface layer slowly wears away, exposing fresh biocide. This is not to say that no biocide is released while the boat is at rest- it is. But both types of paint are prone to some fouling and need to be cleaned periodically. Ablatives are no better at retarding this fouling (in most instances) than any other kind of paint.

Some pros and cons:

Hard paint pros- Durable, typically longer lived than ablatives, typically higher copper content. Cons- Successive layers of paint will at some point have to be removed, cannot be exposed to air for any length of time, limited color assortment.

Ablative pros- Can withstand exposure to air, will not build up like hard paints, wide color assortment. Cons- not particularly durable, low copper content, in-water cleaning restricted in some regions.
I agree with everything above except for the last line. Ablatives can have a high copper content.
 

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Closet Powerboater
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Discussion Starter · #7 ·
Your descriptions of how a modified epoxy paint works is accurate. You're on the right track with your description of how an ablative works, but not quite spot-on. Ablatives work primarily because the surface of the paint "ablates", much like a bar of soap. As the paint moves through the water, the surface layer slowly wears away, exposing fresh biocide. This is not to say that no biocide is released while the boat is at rest- it is. But both types of paint are prone to some fouling and need to be cleaned periodically. Ablatives are no better at retarding this fouling (in most instances) than any other kind of paint.

Some pros and cons:

Hard paint pros- Durable, typically longer lived than ablatives, typically higher copper content. Cons- Successive layers of paint will at some point have to be removed, cannot be exposed to air for any length of time, limited color assortment.

Ablative pros- Can withstand exposure to air, will not build up like hard paints, wide color assortment. Cons- not particularly durable, low copper content, in-water cleaning restricted in some regions.


In a recent post I put up this photo which everyone told me was ablative paint build up. Does this mean that ablative can still build up, but just not as bad or as fast? Does this photo represent 20+ years of buildup and it would be worse if it was hard paint?

I am planning on taking my boat out of the water for several months and I have petit trinidad hard paint on it. What's going to happen? Will it rust? Will it flake? Will it not work when I go back in? Will I sink?

MedSailor
 

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Check the Pettit web site.
 
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I agree with everything above except for the last line. Ablatives can have a high copper content.
Most ablative paints do not have what I consider to be a high copper content (say, 60% and above.) That said, you are correct, there are a few examples of the type that do claim high copper numbers, typically "hybrid" ablatives. Paints that share some properties of both hard and ablative paints.
 

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I am planning on taking my boat out of the water for several months and I have petit trinidad hard paint on it. What's going to happen? Will it rust? Will it flake? Will it not work when I go back in? Will I sink?
My understanding is that Trinidad can withstand about 72 hours out of the water. Longer than that and you will have to repaint.
 

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I live way upriver in brackish although mostly fresh water. Hard paint was awful for me. We were commissioned with Petit Trinidad SR on our bottom. First, didn't adhere very well to my iron keel, although that was likely the prep that was done by the dealer. Second, the paint nearly immediately started getting a slime layer on it. I had to have a diver once a month.

After my first haul, I stripped to bare bottom, epoxy coated, and then applied 2 layers of West Marine PCA Gold with Irgarol, which I hear is bulk repack of a major brand of ablative (it may be Petit). I love the stuff. $150 a gallon (friend has port supply account) and it lasts a loooong time. I have it dived only once every 8 weeks now and there is no fouling at all. When I use the boat, I get a clean bottom.

But again, its all dependent on your local conditions. Because I'm in almost fresh water, I dont worry about hard growth nearly as much as I worry about soft slime growth.
 

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Around here ablatives are very popular for cruisers. Many don't haul every year and our climate allows for year round sailing without need to avoid ice as they do in the east. This makes a multi-season ablative a good choice. We do not have any laws regarding in water scrubbing to worry about as does Washington State. As the chart states ablatives have a more consistent performance throughout their life. And if you do haul for any length of time their effectiveness doesn't diminish.
Pettit Horizons is the most popular choice in the store I work in and has just been lowered in price - by Pettit - to about $169 a gallon.

Here's the comparison:

 

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Closet Powerboater
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Discussion Starter · #15 ·
Hmmm.... makes me wonder in the comparison.....

What do the freighters use? Ablative or hard? The navy apparently uses ablative (based on the surplus paint I found recently).

MedSailor
 

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In a recent post I put up this photo which everyone told me was ablative paint build up. Does this mean that ablative can still build up, but just not as bad or as fast? Does this photo represent 20+ years of buildup and it would be worse if it was hard paint?

I am planning on taking my boat out of the water for several months and I have petit trinidad hard paint on it. What's going to happen? Will it rust? Will it flake? Will it not work when I go back in? Will I sink?

MedSailor[/quote]

The most common reason for ablative build-up is annual painting followed by little actual sailing during a short season. They simply don't wear it off. With a 2-year ablative and a bit more sailing, build-up will be nil. Generally by the time I paint, I can see the prior coat.

The best advice is always to ask around your area. Ask people who use their boats the same way you will.
 

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New Paint Micron extra



Season one after power washing


Season two after power washing and ready for a quick scuffing and the next coat of paint

I life in a super high fouling area due to a out of spec sewer plant that discharges crazy amounts of barnacle larvae food

As such in the warmer times you must wipe off the larvae every two weeks or they will form hard growth no matter the paint used

The two power washings take a huge toll on the pint BUT you have to do it or the sting is horrible :)

After the first two year experiment I have gone to using enough paint for one season as it seems to perform better
 
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