Paint, Saltwater Docking & Trim Tabs

[Magothy Boy]

I am having difficulty keeping paint on the set of Bennett trim tabs that I have on my boat. I keep the boat in the water in the Chesapeake Bay. Last fall I noticed some peeling so during the spring fit out I removed the tabs from the hull, had them sandblasted and then painted them with an Interlux 353 Vinlyux etching metal primer, then Interlux Primocon underwater primer, and then finally with Interlux Micron ablative antifouling paint... by the book. I also installed a zince on each tab and made certain that no paint of any kind went between the zincs and the tabs.

I Noticed about two thirds of the way through the season that the antifouling and primer were liftinf off of the tabs. After the power wash after muy recent haul out, much more paint came off. The stuff that is still there is bubbled. It appears that the etching primer is still attached.

I am thinking at this point of sand blasting the things again and then just brushing/scaping them a few times during the season. Any thoughts or advice on this would sure be appreciated...

Thanks and Happy Holidays,
Kevin


Grady-White 226

[B-Faithful]

I have Bennet tabs on my 231 pro-line that I keep on the Whitehall Creek just the other side of the Bay Bridge and just paint them with the ablative paint I do my bottom. They brush up easily throughout the summer. The key is to put multiple coats on so that it lasts the season. The tabs are made of stainless steel. To my understanding steel can be painted with your regular bottom paint and that aluminum is what you have to watch out for.

[Lacey]

Sounds like there are a few explanations: Underwater primer may not have been fully cured or dry prior to application of top coat. Systems are not compatable. Sufficient profile was created in sandblasting, as vinyl primer is attached. May be an alkyd base or resin in underwater primer or ablative. Zinc and alkyd chemically and electrically react to cause "supponification" or the creation of a "zinc soap" due to this reaction. Soap compromises adhesion. Not sure why a vinyl primer would be used as sandblasting sufficiently provides a surface profile that anchors any coating. Failure is between other two. Needs to be done again, check compatability of systems, dry times of products and under what temperature, humidity, open or closed environment etc., and resin system of products. If alkyds are present, will fail in presence of zinc. Contact Interlux for recommened systems for metal type and blasted metal. Also, is zinc needed for the given metal types. Some suggestions. What was the blasting media?

[JahMussa]

Contact Bennett Marine by phone and ask for Tabman! Tom will certainly help you out as Bennett has the best customer service bar none.

I'm actually surprised he hasn't popped up already... maybe he's finally asleep.

-JahMussa

[Tabman]

JahMussa,

Thank you for the kind words!

Ok, Lacey is on target. The secret to getting anti-fouling paint to adhere to your trim tabs is proper priming, and the best people to tell you what to do are the experts at the company that makes your anti-fouling paint. We strongly suggest that you contact the paint manufacturer and tell them you are painting "304 stainless steel" trim tabs, then follow their recommendations to the letter!
I have had good results following my paint manufacture’s instructions using a two step primer followed by bottom paint.
The experts to ask this question to are indeed the paint manufactures as Lacey points out. Ask the one who makes the antifouling you plan to use to insure compatibility.

Tom
Bennett Marine

[Magothy Boy]

The paint set that I used from Interlux is the exact set up that they recommend for steel to be used under the water line. I even remove the tab parts, had the sandblasted and then painted them inside a heated, humidity controled environment (my house). Followed the instructions to the letter (my wife tells me that there is a picture of me in the dictionary by the words anal rentive!).

I am not looking to blame Bennett or anyone for that matter, I just am looking for advice on how other folks that dock in saltwater treat their tabs..

Thanks,
Kevin


Grady-White 226

[diver dave]

instead of the primcon. The 2000 is an epoxy 2-part. That's what i did last year, and that's what the boat yard here does. Good for about 95% coverage on my bennets at exactly one year in salt water. (continue to use the vinlux metal primer also as etch coat)