New Boat & Bottom Paint, How Often?

Capt. Kermie · Jan 18, 2011

sigbear said:
I bought a 2009 catalina 309 (demo) and had the hull painted with 2 coats of Trinidad Black in Aug. 2010.

The boat is in water at Kentucky Lake, my question is:
How often would you paint the bottom? The dealer said to take the boat out of the water every other year for painting.

The dealer is a very knowledgeable guy, however, his expertise is with boats in Chesapeake Bay all year long.

Sigbear

So what is the implication here...? yours is not in the water all year long...? or is it a question of salt water vs fresh water?
Generally speaking the dealer is correct, apply two more coats every other year if your boat is slipped all year in the salt chuck.
The exception comes into play with trailerables with ablatives, where the boat is only in the water for sailing season then hauled for winter, you can gain a bit more time between paint jobs because the boat is not in the water as long so the paint should last longer.
I put three coats on mine last spring plus a fourth coat arond the water line so I am expecting to get hopefully three years before hauling and painting again. Mine is trailerable but this time around I am slipped so I am leaving it in with extra paint.

Stu Jackson · Jan 18, 2011

Congratulations on your boat.

I'd been doing a haulout every two years. Because of a skiing accident two years ago, I didn't get to my normal haulout, and surprisingly found my five year old paint only now getting long in the tooth. Hauled in late December. Our boat's in the water all year long.

Much depends on the water you're in, not so much fresh vs. salt, but how stuff grows where your boat is sitting, what type of paint (ablative vs. hard, and type and vendor), and how much use it gets.

We have a diver every quarter, too.

Ask around your docks.

Joe · Jan 18, 2011

Two years is fine. You might get more.. it's not a hard, fast rule. Just dive on it occassionally to see how the paint is holding up, you might want to wipe off any algae while you're down there... You should know that anti-fouling properties of hard shell, modified epoxy style paints will be weakened by exposure to air and sun. If you store your boat out of the water much of the year you should use the ablative style paints that work by slouging off paint layers rather than emitting chemicals.

The common practice for ablative paints is to change colors after the first coat.. that way you can more easily tell how much has been sloughed off. If you have black hardshell paint on now... you can apply some red or blue ablative directly over it on your next haul out. Bottom painting is pretty easy for DIY.

My boat is in salt water year round... San Diego water temps rarely get over 70 deg. I can easily get 2 years.... usually 3-5, but I have a monthly dive service that keeps the bottom wiped off and reports to me on it's condition. I use a modified epoxy..

Steve Dion · Jan 18, 2011

Sigbear:

You are in fresh water. If you pull the boat every season you are probably only in the water for 6-7 mos. a year. We get 3-4 years in the California Delta on our bottom paint, we leave our boats in the water year round.

I would check it after 2 years and see what she looks like.

It also depends on the type of paint that you are using. Some paints will loose their protective capability when left out of the water.

RichH · Jan 19, 2011

If you are in fresh water (and there are no 'shell forming' organisms such as zebra muscles, etc.), most lake sailors (including me) use VC17.

My lake boat with VC17 needs repainting about every 4-5 years and only requires yearly 'burnishing' with wadded up stiff 'shiney clay-filled magazine paper' after haulout to insure that it is 'babies ass smooth'. If the VC is applied & kept smooth (no roughness) most times if there is accumulated 'scum', when you get up to hull speed and beyond the scum will usually fall off. If the scum growth is high then its easily removed by scrubbing (because the hull paint is smooth) with a long handled brush or 'squeegee' ... with the boat pulled over (using a halyard from the mast top and attached to an adjacent dock/slip) to a high degree of heel while at the dock.
;-)

Scott T-Bird · Jan 19, 2011

Fresh water ... why paint at all?

That question never seems to come up. New power boats on our lake are never painted ... nobody even offers the service. In fact my marina won't let me paint on the premises so I have gone 6 seasons without, and I make an effort to scrub as much paint off as I can (they won't let me sand blast the old paint off either - they only let me scrape with tarps down on the ground and scraping was a futile effort).

As far as I can tell, the only boats that have bottom paint are the ones that came from somewhere else, many from salt or brackish water.

We don't have a major algae problem so I scrub it off periodically, usually in July, August and about the time when the swimming season is over and the water cools off too much for any more significant slime growth. Most people just go with a power wash or the Slimy Grimy treament at he end of the year to make the gel coat shine like new.

I'd rather have an un-painted gel coat surface in fresh water ... What am I missing?

Peggie Hall HeadMistress · Jan 19, 2011

Whether to bottom paint in fresh water depends on...

The water temps and the length of the season. You're up north where the waters are cold and the season is short...but everywhere south the Mason-Dixon line has a year round season. Boats are only hauled when they need work that can't be done in the water. So except for trailer boats that are washed after every launch and pull out, all power and sailboats are bottom painted in lakes in the South to prevent what we refer to as "a vegetable garden." And it's not just algae...it's a whole variety of botanical species that grow under water...some of it grows long tentacles. It grows fairly quickly, even on painted bottoms...but some decent speed through the water peels it off the paint. But it'll attach itself firmly enough to unpainted gelcoat to require pressure wasihing and sometimes even muriatic acid to remove it.

Paint usually lasts about 5 years.