Freshwater and bottom paint: What happens if you put it off another year?

I have my 310 DA in fresh water. When I bought it last year, the bottom paint was pretty sad but I opted not to have it painted by the Sea Ray dealer/broker. Of course at fall haul-out, it was sadder and I'm thinking I should probably have this done.

But it makes me wonder -- what happens if I kick that can down the road another year? The lake we're on is pretty clean and after haul out the paint looked sad, but we didn't have a lot of bad growth and you can't really see the sad bottom paint when we're on the water.

Is there something awful that can happen from not being super diligent about bottom paint in fresh water? I get that in super warm climates or especially the ocean you can get some nasty growth/barnacles, but this isn't our lake. Is bottom paint in my kind of lake necessary for some reason other than as a biocide?

I've been stretching mine out for years (over 9 now) by simply spot painting the bare spots with a roller each spring. About every other year I paint the sides by the waterline since it gets more sun/algae growth there. I hope the fish under the boat aren't too offended...

There's many people who leave their boats in the water for the season and have never had them painted - meaning a totally bare hull. You'll just have to remember to budget for bottom cleaning at the end of the season - possibly in the middle of the season depending on conditions.

Its not a big deal, but if you get a lot of slime/algae on the bottom, it has a surprising amount of drag on the hull, which slows you down and costs you fuel. How much is hard to guess, but its something. I touch mine up each spring and about every three years I go over it all. Next spring is my next full paint. I use a water based ablative paint (Aquaguard) so only need basic rough sanding on most areas, followed by a good pressure wash before painting. It works well in our waters/marina (clean fresh water, but about 80 degree temps for most of the summer)

We kept a 26 foot Express in the water for 7 seasons and never painted the bottom. I would pull it up on our beach and scrub the smile, sides and transom every 2-3 weeks just for appearance. The bottom did pick up stains from the tannens in the water but we never saw them until the boat was stored inside on a rack. There did not appear to be any adverse effects from not painting it. We used Zing (HCL) to clean the scum off in the fall and everything cleaned up with ease.

Our 370 when in CO was a clean bottom. Very little cleaning required at the end of the year - one of the many beauties of a lake fed by snow runoff with rock bottom and sides.

Moved to TX about 6 months ago, with a new (to us) boat on the way. Made darn sure the bottom paint was good (done in the fall this year) and will keep up on it. TX lake looks.....like split pea soup. Apparently here you have divers go down every other month or so and have them clean the bottom while in the slip.

Point is, the environment dictates what's best for your bottom.

I have an additional question regarding the painting of hull bottoms: I was under the impression that unpainted gelcoat, over time, could develop "blisters" which could lead to the delamination of the underlying fiberglass. It sort of justified the Surveyor using the hammer on the hull during a survey.

Is there any truth to this impression?

Jaybeaux

Jaybeaux said:

I have an additional question regarding the painting of hull bottoms: I was under the impression that unpainted gelcoat, over time, could develop "blisters" which could lead to the delamination of the underlying fiberglass. It sort of justified the Surveyor using the hammer on the hull during a survey.

Is there any truth to this impression?

Jaybeaux

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Sort of. A lot of it depends on the type of gelcoat resin that is used. Sea Ray has been using vinylester for a long time, now - well earlier than your boat's year. Occasionally, you might see one here or there, but they will be small and not cause an issue. Blisters are, for the most part, pretty much non-existant with vinylester gelcoat. You could barrier coat it, but there really isn't any need to do so.

FYI, "bottom paint" isn't impervious to water. Meaning, if one did want to apply a coating to stop blisters, bottom paint won't do it. The hull needs to, specifically, have a "barrier coat" applied (basically an epoxy).

Depends on the age of the boat. Superior resins were developed over the years and were used and tended to prevent blisters. SeaRay adopted these blister resistant materials quite early. Still, blisters can and do develop on some boats but not all. Bottom paint's purpose is to prevent marine growth on hulls. To prevent blisters, barrier paints were developed.

Lazy Days beat me to it. Spot on.

sbw1 said:

Lazy Days beat me to it. Spot on.

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Every once in a while I'm the faster typer! Usually not...

Thanks guys. I learned something!

Lazy Daze said:

Sort of. A lot of it depends on the type of gelcoat resin that is used. Sea Ray has been using vinylester for a long time, now - well earlier than your boat's year. Occasionally, you might see one here or there, but they will be small and not cause an issue. Blisters are, for the most part, pretty much non-existant with vinylester gelcoat. You could barrier coat it, but there really isn't any need to do so.

FYI, "bottom paint" isn't impervious to water. Meaning, if one did want to apply a coating to stop blisters, bottom paint won't do it. The hull needs to, specifically, have a "barrier coat" applied (basically an epoxy).

Click to expand...

Thanks, this was the kind of "hidden" problem I was worrying about by not being retentive about bottom painting.

And really, blisters aren't necessarily a death sentence for a hull, either. Some cases are worse than others, but here's a personal example...

We have an '82 17' Sea Way (yes, that's a "W") that's been passed around to different family members since '82. It spends 5-6 months in the water (Maine) every year, before being put on the trailer for the winter. After a few years, we noticed blisters starting to pop up. None were really much bigger than a pencil eraser or or so. Eventually, more and more popped up till it looked like the bottom of the hull had chicken pox. But come Spring-time, they were pretty much non-existant again as they dry up over the winter. Occasionally one or two would pop (either from the pressure of being put on the trailer or freezing over the winter if it didn't dry out before cold temps). Most of the time we saw the popped ones and would fill with something like MarineTex.

So that's how it's been for 35 years now... the hull gets chicken pox during the Summer and they go away over the Winter. And you know what? The boat still floats and seems to perform just fine. I'm not advocating to anyone else to just let blisters go unchecked, but it doesn't necessarily mean to throw in the towel. I do, however, have no doubts that if this boat stayed in the water year round it would be worse. But then this is just a little 17-footer where I can simple pull the 75HP off, flip it upside down on land, grind, fair and epoxy/barrier coat.