How much bottom paint?

[Chief]

Sorry if this has been asked before; I could not find my question in a a search of the CP23 forum. It is time to paint the bottom and I am not sure how much bottom paint to buy. Will a gallon be sufficient or should I buy more? Thanks for any guidance.

[notbob]

A gallon will be plenty.

For comparison purposes, I have a 31' PSC Mariah that takes less than a gallon to paint.

[Yamaha33410]

How many coats does that gallon do though?

[notbob]

A single thick coat of ablative should last two seasons.  There is no reason to do multiple coats, especially if you are dry sailing the boat.

[notbob]

Here is a good article from Interlux about bottom paints.

http://www.yachtpaint.com/LiteratureCentre/antifouling_101_usa_eng.pdf

Also, some people say that adding red chili or cayenne pepper to the paint helps stem growth.  I've tried this with somewhat favorable results, YMMV.

[brackish]

Lot of variables here.  I just finished mine in September.  A gallon will put on about one and half coats.  I bought two gallons and put on three coats, had a little left over, used it at the water line and bottom of the keel.  I leave mine in the water for three years cleaning it in water once each year. The cleaning hastens the ablation, that is why I want the extra thickness.

The way I look at it, the hard part is cleaning and prep, painting is easy.  Just makes sense to me to limit the number of times I have to do a nasty job, so do as much as possible when you have to.

I'm in relatively warm fresh water.

[Yamaha33410]

I concur Brakish, from everything I've read, especially if you clean it a lot, you should put on 3-4 coats of bottom paint...

That is unless you like buying a lot of materials and prepping the boat for bottom paint annually... never met a single person that would think that sounds like a good idea or a fun time... Rather Sail then work on boats

[notbob]

When the paint gets too thick, you lose adhesion.  That being said, the paint you choose will tell you on the can what they recommend for coats.  I work professionally on boats, so hauling every year or two is common practice, whether it be for coast guard inspection or to keep the weight down for racing.  I guess if you don't really care, then yeah, slap a ton of coats on and forget about it for a few years.

[Chief]

Many thanks to each of you for your thoughtful response.

[brackish]

When the paint gets too thick, you lose adhesion.  That being said, the paint you choose will tell you on the can what they recommend for coats.  I work professionally on boats, so hauling every year or two is common practice, whether it be for coast guard inspection or to keep the weight down for racing.  I guess if you don't really care, then yeah, slap a ton of coats on and forget about it for a few years.

I use Blue Water Marine SCS 45 Copper Shield.  They recommend 3 coats, however, paint makers will lean to recommendations that sell more product.  I've never had an adhesion problem.  A long time ago, I used to race GORC.  Most serious racers would use hard paints and pay a diver to clean before each race, or have the yard pull for a pressure wash.  Money was no object for these folks.  I think you'll find most folks with these Compacs don't do a lot of racing.  I think the PHRF on the 23 is a little tight to do any good.

I do care, very much so, about having to climb around under that boat to pressure wash, scrape, sand, and paint.  Don't want to do it any more often than absolutely necessary to protect the boat and to keep reasonable speed and reduce drag.  And if I dry sailed, it would be wax only.

[notbob]

I guess if you don't really care...

Poor choice of words on my part; apologies.  And yes to still using hard paints in the racing community. Still using baltoplate, still wet sanding bottom jobs.

Here's a good one on all the different types with pros/cons and brand names:

http://myboatsgear.com/2017/01/08/bottom-paint-guide/

[Potcake boy]

Been using Petite Hydrocoat for a couple of years. I thin 10% with water as recommended for spray, but apply with roller. gives a very nice smooth finish and I get easy two coats per gallon. Occasional scrub is necessary her in Florida. Next I will probably try the Hydrocoat Eco, to hopefully avoid the soft growth.

[brackish]

Next I will probably try the Hydrocoat Eco, to hopefully avoid the soft growth.

that's a copper free right? Water based?  If you do that keep us up to date on how it is working out.  At some point we'll probably all have to go to that class of paint.

[Potcake boy]

Yes, copper free water based. I just launched my boat with new paint so it will be a while before I have to re-paint. Remember, our seasons are backward here in Florida. Actually there is no sailing season here. The reviews so far are favorable to the new Hydrocoat Eco, so I am looking forward to using it. I really like the water based paint in use, but the Ergarol component is no longer available. I used to scrub my trimaran but it was easy to reach underneath with 12" draft, haven't tried the 23 yet, but I think it will be inevitable. Hydrocoat is comparatively hard so if you don't use your boat frequently it will accumulate a fair amount of soft growth, but easy to clean.

I really do like the idea of a bottom paint that is not harmful to marine life. When you have the opportunity to sail in clear salt water you come to appreciate the world below the surface. Anything that goes into the water is inescapable by marine life. It is not just a moral issue, but one of existential consequence for the entire planet. I would prefer staying here as opposed to living on Saturn's moon, or Mars - not too sure about the quality of sailing in those places. It would be more like "sails on the red sunset", no thanks.