Any Tomcat owners using ablative paint?

M

matt_unique

New member
Good afternoon gentlemen.
You may have read some of my posts about paint pursuits and experiences. I have never been able to get more than 4 months with any paint before I develop a sweater and need to power wash. 2700 nautical miles in three seasons means I am not sitting still and I have very little paint flaking so I know it was applied properly and adhering well.

Last season I used Pettit Vivid with the same results. I decided to try their top of the line products for the next full paint job (and this winters touch up). For ablative this means SR60 and for hard paint Trinidad SR. I sure like the idea of not having to power sand several layers of paint every few years. Last season before I applied the Vivid I sanded off a lot of paint, cleaned the hull with acetone, then applied two good coats.

Trinidad SR looses it's mojo if out of the water for 60 days per Pettit and will need to be sanded off every few years to avoid build up. I have resisted ablative paint due to my 22 knot typical cruise speed causing the paint to slough off prematurely.

With that as context - how many Tomcat owners are using ablative paint and have you experienced our cruise speeds to wear the paint too quickly?

Thanks!
 
BrentB":36c86i31 said:
Why does Trindad SR lose its effectiveness in 60 days when out of the water?
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That's a good question - I don't know. I called Pettit to get the direct scoop and this was what I was told. I have heard of this with other paint brands as well. Basically after application you will want to get it in the water before 60 days has elapsed. This would of course take away any alleged multi-season applicability but from my experience there is no such thing.
 
BrentB":3i2i8hiy said:
Why does Trindad SR lose its effectiveness in 60 days when out of the water?
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I think it's because the copper in the paint oxidizes with the O2 in the air when out of the water, becoming ineffective.

It's the copper that is lethal to the biological systems in the plant and animals that grow on the hulls.

One single copper nail can kill a huge tree.

Joe. :teeth :thup
 
ok thanks Joe but the paint uses cuprous oxide not pure copper.
Does it further oxidize in the paint matrix when exposed to air over time? I thought maybe it was a breakdown of the another ingredient
 
Matt:

To answer your original question: I use Micron CSC, which is an ablative paint. We cruise at 25-27 knots for around 125 hours/year. The wear is very uneven- some areas need a touch-up every 6 months, others don't wear much at all.

Most of the paint wear and flaking is at three points: 1. mid-ships (both on the outer and the inner surface of the sponsons- I assume this is the air/water interface at planing speeds; 2. at the leading edge of the sponsons, and 3. on the horizontal surface in the tunnel. I haul the boat out every six months for oil change and maintenance. At each haulout, I gently wash the sweater off with a pressure washer; this also removes any flaking paint. I then sand the flaking areas, clean with "Special Cleaner" from WM- I think this is xylene- and put 2-3 coats on the affected areas. I typically thin the paint down at least 10% with the special cleaner so that it rolls better. Any left over paint goes on the rest of the hull until the paint runs out; I do a very light sanding before painting over the less-worn areas.

In other words. I never deliberately paint the whole hull- I just do six-monthly touch up on the affected areas with 2-3 coats and put a single coat on the rest of the hull. This system has served me well. And no, I do not worry about the extreme knife-edge at the bottom of the sponsons- I leave the boat on the trailer and get as close to the bottom as I can.

The same paint goes on the transducer- seems to work well and has not hurt anything.

Now, if someone can tell me how to keep the barnacles off of the motor mounts....the anti-fouling paint for aluminum surface does not seem to work worth a darn!
 
I am planning to get the Tom Cat's bottom repainted (after 4 years, I think it held up pretty well) but I became concerned because of the issues raised in this discussion so I emailed LaConner Maritime (they did my original job and will do the repaint). This is the reply that I received from Eric:

There are paints that Pettit makes that cannot be out of the water for long periods of time and remain effective but vivid is not one if them.
Pettit Vivid is more or less the best paint to use for boats stored out of water. It has the effectiveness of the high copper paint but does not expire when out of the water. It was originally engineered with trailer boats in mind knowing that they will be out of the water for quite some time. Hope that helps!

If you would like to know more about Vivid here is a link: http://pettitpaint.com/catalog_browse.asp?ictNbr=14
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Warren
 
Thanks for the replies.

The author of the article posted above says hard paint, such as the Trinidad SR, is the best solution.

Alok - how often do you have to sand down layers of your ablative paint?
 
Alok - how often do you have to sand down layers of your ablative paint?[/quote]

I never sand down layers of the paint, since I have always used the same paint. I just put a new coat over the old one after preparing the surface as above.

I do a very light sanding followed by a light rub with the "Special Cleaner" in areas that have held up well before putting on a fresh coat. The xylene seems to gently soften the older paint and, I think, helps the new coat adhere better.

A little heavier sanding if the epoxy is showing, just to scratch the epoxy and allow a physical bond. Of course, I do all sanding by hand; I do not believe that I have removed any significant amount of epoxy over the years. I then use the xylene as above to clean the surface before painting.
 
Matt:

I have not noticed any build-up- I guess I just tend to put more coats in areas of heavy wear (which are obvious because you can see little "dots" of epoxy peeking through) and less where the paint appears to have weathered less. It all seems to balance out.

At Tomcat speeds, I guess the rate of ablation is largely determined by the number of "moving" hours. The 6-month interval between touch-ups (set by the need for an oil change) seems to be about right for the 50-65 hours of use I put in between re-coating. If someone puts in 100 hours every 6 months they might have to touch up the paint more often. If someone put in only 25 hours but uses the touch-up schedule I use, they will probably get some build-up.

In addition to the ablation caused by the friction between the water and the paint, clearly there is additional turbulence at the air-water interface midships at planing speeds which may be why the paint gets stripped off unevenly in that area and the little dots of epoxy become visible. It does not seem to matter how many coats I put in this area- I always get the same wear pattern. Maybe I am not doing a good enough job of bonding the paint to the epoxy.

I have toyed with the idea of having a different color as the first coat, followed by two coats of black so I can check the rate of wear better on the rest of the hull, but my current system seems to work well enough.

If one thinks about it, over the years there must have been very few boats that were kept in the water most of the time AND cruised at 25 knots AND had the option of being put on a trailer and kept out of the water for weeks or months! No wonder we have unusual bottom-paint issues.
 
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