Bottom Paint Question

[canoeman256]

Hello all,

I am finally going to be forced to paint the bottom of my boat and I have a couple of novice questions.

First, my boat is a Catalina 22. Will one gallon of paint be sufficient, too much or not enough for a couple of coats (is 2 coats enough)?

Second, I don't know what kind of bottom paint is currently on the boat except to say that it is very chalky and will rub off on your hand. I suppose that means it's ablative. I assume that the new coat must also be ablative in order to be compatible. Any ideas on which brand (and I don't want to break the bank here). I am strictly a cruiser and do not race so I don't necessarily need a real slick finish.

I keep my boat in the water year round in the Tennessee River, which is fairly nutrient rich. There are a couple of boats near mine that are apparently growing vegitables under the waterline and I don't want mine to turn into a food plot.

Any advice will be greatly appreciated. I've never used bottom paint before, but hey, how difficult can it be?

Thanks
Canoeman256

[Sailormann]

One gallon is too much. I used 3 quarts and got 2 1/2 coats on a 30 footer.

I don't think that there is much difference in price between the various paints. They are all vastly overpriced.

If you are in freshwater, then VC-17 is a good choice. Goes on easily and is a hard ablative, hence buildup is less of an issue. Doesn't adhere well to some paints though so ....

...it might be a good idea to try to find out what the stuff on there is first. Don't be shy about trying to track down the person who applied it - they won't mind.

[Quickstep192]

Your conditions sound similar to mine. Where I keep my boat, fuzz will grow on the bottom, followed by barnacles which seem to colonize on the fuzz. I use Interlux Micron extra with Biolux which is an ablative paint. The biolux does seem to help keep the fuzz away. One thing about ablative paint is that it exposes new anti-fouling "stuff" as it wears away. The only way to make it wear away is to use the boat.

On a re-coat, a gallon is enough for one coat on my 24' boat with enough to put a second coat on the rudder, the leading edge of the bow and the leading edge of the keel. These areas wear faster than the rest because of the flow of water over them. If I still have paint left over, I add a third coat on the high wear areas.

As a side note, the first time I painted the boat, I made the first coat a different color than the final coat. This makes it easy to spot where the paint has worn off.

[canoeman256]

I agree, they are all vastly overpriced, however, I just learned from a friend of mine that Lowes will order bottom paint (any sort) and you will get it for approx half price! Both he and his son have ordered from them.

I have no idea who put the previous paint on the boat. The PO never painted it in the 3 years he owned it. Who ever did it put yellow on as the first coat and followed it up with blue. I figure that if I just replace the blue, I'll see that it needs repainting when I see the yellow again.

By the way, how much sanding (beyond just ensureing that everything is smooth) has to be done?

[sailingdog]

canoeman-

it is pretty typical for the first coat to be a different color, so that you can tell when repainting is overdue. I would put second or third coats on the areas that will experience extra wear—like the water line, the leading edge of the keel, the leading edge of the rudder, and the leading edge of the bow.

[Sailormann]

Hmm - not familiar with yellow - SD might know which paints come in that colour. Usually yellow means lead/chrome/zinc... but it might be that some manufacturer is running a yellow bottom paint.

Before you start sanding, test a little bit of your new paint on your old paint. Buy the smallest container you can get to test with, you can go back and get more if it works.

Give it a day or two to harden and see how well it holds. If it seems to adhere well, AND, if there is not too much build-up on the hull, then all you need to do is take a wet 3m scrubbing pad - the green ones they use for pots, etc. - and smooth everything out. You don't need to take everything off. If it doesn't adhere, then look for something with a different binder...

[sailingdog]

I believe it might be a Pettit Vivid Antifouling paint. See LINK. AFAIK, Interlux doesn't make a Yellow bottom paint. Pettit and Interlux are probably two of the larger providers...

[Freesail99]

ViViD made by Petitt makes a bright yellow bottom paint. I put it on my boat. I applied it over 4 coats of Mas epoxy.

[sailaway21]

VC 17 is one of the less compatible paint selections to be made for applying over unknown existing bottom paint. I stripped my bottom as a result and am happy with the VC17. It's used quite extensively in fresh and brackish waters.

[Fstbttms]

Originally Posted by Quickstep192

One thing about ablative paint is that it exposes new anti-fouling "stuff" as it wears away. The only way to make it wear away is to use the boat.

True, but only sort of. Ablative paints are designed with carefully placed chemical decay. The surface of the paint disolves (helped by the boat's motion) and as it does, fresh surface and biocide are exposed. The point is, both ablatives and epoxies release copper at a controlled rate during the life of the paint, whether the boat is moving or not. And when the copper is gone the paint becomes ineffective, regardless of how much is left on the boat.