Dumb bottom paint question

Does a freshwater lake boat really need anti fouling paint below the water line? That stuff is nasty and every time I rub up against it while doing maintenance I'm semi-permanently stained. I know the PO used to go up to the San Jauns every year so I'm guessing that's why it has a ablative paint on the bottom. Just wondering If I need to also use it when it comes time for a repaint?

Thanks,

Curt

I'd ask other local boats what they use. Or a local boatyard. "Local" seems to be important in bottom paint selection.

I think there was a recent thread on this... I think what makes the most sense is a hard paint and dive on it every week or as needed to wipe off the slime. (Yes, I have one dock neighbor who actually does. Every week.) Or if it's a trailer sailer, maybe nothing?
And here I just put on another three coats of ablative... it was on sale...
Although one nice thing about ablative - it comes off easily with a pressure washer when it's time to correct that mistake.

When I was lake sailing, many of my colleagues used VC17, which is a very thin coating that dries almost instantly, so one could put another coat on almost right away. It dried hard, so would not rub off like an ablative paint, but was so thin that it would not accumulate like hard epoxy paints. In the fall when hauling for the winter, they would simply wash off any slime with a pressure washer--very easy and left the hull perfectly clean.

At that time I used a white Interlux epoxy paint with Teflon that made the boat faster, but it didn't have any antifouling properties. But I like to swim, so I did clean the hull regularly through the summer. It never accumulated much algae, but some over the course of a week. In the ocean that's really not an option--even with antifouling paint stuff begins to grow quickly. I still go swimming regularly to keep the hull clean--I'd hate to see what it would be like without antifouling!

Frank

cagarren said:

Does a freshwater lake boat really need anti fouling paint below the water line? That stuff is nasty and every time I rub up against it while doing maintenance I'm semi-permanently stained. I know the PO used to go up to the San Jauns every year so I'm guessing that's why it has a ablative paint on the bottom. Just wondering If I need to also use it when it comes time for a repaint?

Thanks,

Curt

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Yes you do unless you’re in the water weekly to scrub the bottom.

Unlike salt water where barnacles are the biggest problem, algae is the biggest issue followed by Zebra Mussels here in the Great Lakes. At the end of the season a good power wash knocks off all the slim easily with no scraping or sanding. THAT makes it well worth the effort and cost of applying it.

We’ve been using VC 17 as it is a thin but protective coating that doesn’t mess up the hull’s smooth bottom since so many are weekly racers up here.

Awesome! Thanks for the info people!

Most of the boat owners I knew on the Great Lakes (including me) used VC-17. It wasn't great, but it worked well enough, and there was no seasonal sanding required before re-application.

Pettit SR-21 / West Marine FW-21

We sail on Lake Michigan and have used VC17 successfully for years. A few years ago I got a deal on some Pettit SR-21. Pretty much the same thing as VC17 but it seems to go on just a tad thicker and lasts longer. I have found that I can go for two to three seasons without bottom painting.
SR-21 is also branded as West Marine FW-21. West Marine usually runs a sale on it in the spring.

JSM said:

We sail on Lake Michigan and have used VC17 successfully for years. A few years ago I got a deal on some Pettit SR-21. Pretty much the same thing as VC17 but it seems to go on just a tad thicker and lasts longer. I have found that I can go for two to three seasons without bottom painting.
SR-21 is also branded as West Marine FW-21. West Marine usually runs a sale on it in the spring.

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Thanks for the tip on the Petit paint! We’ve been using VC-17 ever since being up North in Lake Erie. When living and sailing in Florida previously, I used only Petit bottom paints as it was a Florida based company and formulated for Southern warm waters. It worked well and I used the hard bottom paints so as not to have swimming guests come up covered in leaching bottom paint.

Question for you...You say the Petit is a tad thicker. Does it still flow as smooth to maintain a superb bottom surface for racing purposes? At the moment, our boat bottom is smooth as window glass with the VC-17. (Spent two years getting all the salt water barnical moon craters off her bottom to make her really competitive.)

kapnkd said:

Question for you...You say the Petit is a tad thicker. Does it still flow as smooth to maintain a superb bottom surface for racing purposes?

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The solvent base for the Petitt product seems a bit more viscous and I find that the paint is not as "watery" as VC17 and less likely to run down the hull and splatter if you load the roller up too heavily.
The end result seems to be the same as VC17. We took our bottom down to the gel and applied a new epoxy barrier coat and SR21 two years ago and have been pleased with the results.
I have also found over the years that these paints can be thinned with alcohol (way cheaper than the manufacturers thinners !) should you need to stretch the product or slow down the rapid evaporation on a hot day.