Bottom paint question

[kerk fisher]

I'll be repainting my 1990 34' wing keel Catalina.  We sail the great lakes so we've allowed the bottom paint to get pretty sparse.  Q:  How many quarts will I need of red VC-17m extra, how many coats, and how much do I thin it (a fellow sailor says about 1/2 cup of acetone to a quart)?  Also, I may be doing a little epoxy repair on the keel and will need to prime it before painting.  Q: What primer would adhere to both the epoxy and the bottom paint?  Thanks, Kerk

[sailaway]

2 to 3 qts I  use a plastic joy soap bottle or any squirt bottle. Then I put the paint right on the roller it saves a lot of paint from evaporation. Charlie

[Jim Hardesty]

If the bottom wasn't painted with VC17 bofore you need to strip all the old paint and clean the hull.  It takes me about 4 to 5 qt.  I use a pan and roller some brush.  I don't realy thin it.  I do 2 coats on the leading edges.  After painting I just leave the pan and roller dirty, then next year I just pour some denatured alcohol in the pan to desolve the old paint in the pan, roller and brush.  When I thin I use denatured alcohol.
I use my boat more than most about 1,000 kn a season.  So I'm liberal with the bottom paint.
Jim

[Ron Hill]

Kirk : I takes me about 3/4 of a gallon to paint the bottom - been doing that for 25 years.  I wouldn't screw with anything else, but the paint manufactures recommended thinner and then only thinning if I were painting on a HOT day!

A few thoughts

[Dave DeAre]

I have been using VC-17 for at least 20 years now VC-17 Extra. I use 4 quarts, including under the wing keel and cradle pads. I use a roller tray and a 7" fine roller (mohair?) Just finished for this year. Works for me.

[Ron Hill]

Guys : For what it's worth -- I've started using hard bottom paint on the bottom of the wing. 
Do that incase I "bounce" the bottom, as the soft ablative paint tends to rub off!!

A thought

[Clay Greene]

As a fellow Great Lakes sailor, I would not use anything other than VC-17 or SR-21 - they are the only paints that seem to work against our slime.  Ablative paint does not seem to ablate in fresh water so it is pretty much worthless. 

We just did the bottom on our C387 with 2 1/2 cans of SR-21 (you can put SR-21 over the top of VC-17, it is cheaper and it works just as well).  We got our C34 done with 1 1/2 cans. We use black foam rollers we get from the paint store (gives it a smooth finish) and put on one thin coat.  All a thicker coat does is build up on the bottom and slow your boat down.  You want just enough that most of it comes off with the power washing in the fall and the rest sands down in the Spring.   We don't thin it with anything. 

If you are going down to bare metal on the keel, use Pettit Metal Primer followed by a coat of Pettit Protect (both a primer and a barrier coat - you only need to do one coat if using it as a primer) before the SR-21.  If you're only repairing the fairing (for that I would suggest Pettit EZ-Fair, which is an epoxy).  I don't work for Pettit but I like their products better than Interlux. 

[kerk fisher]

oops. I said keel repair when I meant rudder.  Thanks for all your input.  Sounds as if 4 qts, not thinned with a mohair roller.  I do have a question about the rudder repair but I'll start a separate thread.

[Clay Greene]

I would strongly recommend using a foam roller, not mohair.  It is going to produce a smoother finish and you will waste less paint.  Why use a thin racing paint and put it on with a roller that leaves a texture?  Plus the foam rollers are maybe a quarter the cost of a mohair roller. 

If you are only doing one coat and are covering the can when not pouring it in the pan (VC-17 or SR-21 evaporate like crazy), I can't see how it should take more than two cans for a C34.  My memory is that it took 1 1/2 for ours and we had half a can left over for under the pads and the keel when we were up in the slings.  We threw part of that can away.  Unless you like sanding or soda-blasting old paint, more paint is definitely not better. 

[Fred Koehlmann]

I agree with claygr. We're also on the Great Lakes (Georgian Bay), and the one time that we did the whole underside, we used only two cans. At $70-$80 CDN per can (although Westmarine had a sale last week: $60), the incentive was to put it on thin and quick. I use a foam brush for the water line first ( I have a steady hand and don't tape), and then a foam roller for the rest. No diluting, but only pour minimal amounts into the roller tray to use. Work quickly, without spraying with the roller. If you can do the work on an over cast or cooler day it can help reduce evaporation.

This year I did some crack fixing on the skeg around the strut, which included sanding and epoxy work. So I wanted to cover my work afterwards with bottom paint. We use the VC-17 red. I pout a couple coats right over the cured epoxy barrier, and since I had the rest of the can I continued with the rest of the underside. I managed to get half the hull done. I start with the parts that get the most light (that's where the algae likes to live), and then circle the boat getting lower and lower. This is at least the second season that we didn't do the keel. In the fall, anything that is still on washes off with the pressure washer.

Sailing on the Great Lakes has some nice benefits (even though the season is rather short), but other than zebra mussels, we don't have too much bottom crap to worry about, at least in Georgian Bay.

[Clay Greene]

Georgian Bay - wow!  That is Xanadu of Great Lakes cruising.  Now I see why you live 200 km away from your boat.  We'll get there some day. . . .

[kerk fisher]

What did you use for your epoxy? and barrier coat?  Did it take a long time to cure before the vc-17?  Since we live 600 miles from our boat I'm trying to plan/time a rudder repair so we can get in the water as quickly as possible.

[Bobg]

I sail lake superior, some of us up here think any bottom paint is a waste of money, a lot of sailors just use house paint to make their boats look better on the hard, when I pull my boat there is no significant difference on the bottom in the fall from the spring. I suppose if you race there may be a minuscule of difference in speed, hardly worth it though. 

[Ted Pounds]

Kerk, actually you want to put the VC-17 on before the last coat of epoxy cures so that the pint gets a good bond. See the directions for details...

[Clay Greene]

Ted is right - there is a limited window after the last coat of barrier coat when you are supposed to put on the antifouling paint.  We went with Pettit Protect over Interprotect because they recommend fewer coats (three versus four, if I remember correctly) and there is a longer window both between coats and after the final coat before putting on the antifouling paint.