T400's

I am contemplating ablative antifouling on my 30' superboat which has a bald spot on the paint and always ends up slimy and barnacled by the end of summer. I'm not sure whats on the bottom now, just a durable white gloss paint and red transom. What mph will I stand to lose if I put on antifouling, say the best and whitest sailboat type? And about ten cans of the clear for the drives too I guess. It being an older boat I don't think it will affect the value too much...
What does everyone use on their bottom for speed, paintwise and wax? Is a normal white epoxy paint ok?
thx

BY U BOY

epoxies are great for immersion BUT will loose its gloss,discolor and eventually chalk with exposer to sunlight.

T400's

what paint does work best on the bottom, or is just regular Imron type paint what everyone uses, with wax..?

madbouyz

Don't confuse antifouling with regular gloss type finishes.
If you are planning to stay overboard , which is what I think you're saying you will need anitfouling paint.
Where are you boating anyway ?

Right now , the whitest white I 've seen is Pettit's 'Vivid' line.
(If it's white that you're looking for)

I would say that if you take the time and do it right you could see a drop of between 3-4 mph.

phragle

iTrader: (3)

glass dave was telling me about some kind of bottom paint with teflon to do mine, but I havent researched it yet...still have a lot of sanding to do first

T400's

yes thats my question, do I keep a gloss finish non-antifouling paint, whats the chemical makeup of it...not enamel or laquer... imron type paint... or go with the new vivid antifouling stuff... Long Island Sound, might be one of the worst areas for bottoms...
And the paint thats on now is in VG shape... why should I bother to sand it off, why not just scruff it well. theres not much of it there, not built up at all. I guess the antifouling paints need a special surface prep to adhere...
My boat is trailered but spends a few weeks in every year here and there.
I'm going to see if Pettit has any info on the web as far as prep goes.

madbouyz

The problem is you're going to be hard pressed to find any kind of 'gloss' paint that will stand up well underwater for more than a week or two.
If you go antifoul be ready for the arguments about how "you've just destroyed your boat" etc etc.
I say , just make sure you sell it to someone who will keep it overboard too ! (And will thus want a painted bottom)

Whichever brand you go with , they all have their prep instructions. They all recommend barrier-coating now, don't skip it !

BTW ... the last of the 'true whites' ended with the banning of TBT in paint for bottoms.
The Pettit Vivid white has a very slight 'cream' tint to it but is the whitest I've seen for long while.
I have no idea how good it actually is at this point , but hopefully will in about 7 month's time .

T400's

I am really leaning towards the vivid. I used a hydrohoist for my cigarette and the bottom would still stain really bad in the ****hole of a harbor I was in. I used to put ON/OFF in a spray bottle and put on rubber gloves and spray it down and brush. That was the system I was using for my superboat these last few years, only problem was I couldn't reach some of the spots where it sits on the trailer. Now no more boat slip/hydrohoist/cigarette/$$$.
I don't think the hassle is worth the supposed 3mph I lose and the boat is overpowered (if thats possible) anyway.
So what is barrier coating?

madbouyz

Barrier coating is the first and most vital step in antifouling a boat today.

On a new correctly prepped hull the barrier coat is a two part epoxy coating that prevents water penetration of the gellcoat and thus osmotic blisters down the road.

Nearly all of the paint manufacturers have their own systems that work together. Generally your first coat of antifoul goes on while the last coat of barrier-coat is still tacky to give a good chemical bond.

Most of these systems are formulated to be applied as easily and quickly as possible ... imagine doing the bottom of a huge trawler or worse... So they tend to be applied by roller one coat after the other. A nice 'bumpy' finish YUCK !

The last one I did , the boat was upside down and I sanded in between coats ... all brush applied. The final finish will have as little impact as possible on the top speed.

Panting the bottom of a 'performance' boat is a necessary evil if you stay overboard.

T400's

aha, chemical bond between coats while tacky,,, that explains it very well. I just estimated the cost... around 1500 for a 30' boat around here including materials, if I use the 200/gal stuff, 2000 maybe. Yikes.
Should add to the value not vice versa. Its a gamble how long you can leave it in before real barnacles start to grow. It depends on the water temp. Two weeks is safe but you will have some on/offing to do and the spray bottle nozzles melt in about 15 minutes. No place around here does rack storage for a boat this size. still between a rock and a hard place, but thanks for your info.