Bottom Paint Questions

[Ken M.]

New to owning my 31 (it was my Dad's). Many many questions, and my Dad isn't around to answer them. I look to this board as a surrogate :-).

The boat is laid up for the winter, and I was looking at the bottom. In places, the bottom paint is coming off in sheets (up to about 6 inches square), in other places it looks sound. Clearly there are many coats. I'm wondering if this is slowing the boat down (not much, but every knot counts).

1. At what point do you break down and strip the old paint off and start over?
2. What's the best way to remove bottom paint?
3. Why don't people paint shafts?
4. How many gallons of bottom paint does a 31 need?
5. My yard requires environmentally friendly bottom paint. Any suggestions?
6. Am I crazy to want to do this myself, or should I just bite the bullet and have the yard do it?

Thanks very much,

Ken

[Pete Fallon]

KenM,
How old is the boat?, after 20 years it's time to strip the bottom, soda blasting is the only way to go, have the yard do it, it takes just under a gallon per coat of bottom paint. If you soda blast the bottom your going to have to barrier coat the entire bottom and fill all the pin holes and any blisters. Use an ablative paint such as Sea Hawk or Petit paints. Some people paint shafts others use prop speed, some don't paint at all. Good luck, if you do it your self, invest in a good canister mask or better yet a self contained breathing system.
Happy Holidays
Pete Fallon

[Kevin]

Speed on my 28 went up about 1 to 1.5 Knots if I recall. There is a thread on here about it. I also put VC Performance epoxy on so it was not apples to apples comparison with starting over with antifouling paint.
Easiest way to get the paint off...........pay someone who specializes in it, cash is king. One of the worst jobs I have ever messed with.

[Stephan]

Ken-
You post presents several questions and implies many more. I'll take a crack at the most basic one.

You are not crazy to consider doing this yourself.

I've always wanted to do each job on my boat myself. With the help of the folks here I've been able to take on much more, and the advice here has meant huge yields considering my ability. Doing the bottom of my boat was a step toward making it my boat and was a discipline so I was familiar with each through-hull, joint, fitting, etc. It also made the pleasure from having someone else do the job last year that much greater.
I do note that I have always been in yards where I was friendly with the owner of the yard and part of the culture of the place included working on your own boat. It seems there are fewer and fewer of these yards around. If this isn't the case for you then maybe look forward to doing the bottom yourself another year when you haul out somewhere else.
Best,
Stephan

[Dug]

Hey Ken,

Welcome!!!

All said before me is true. A bit more detail. What Pete said is right on. You are well served to soda blast. Or walnut shell. Both are way less intrusive than sand. Barrier coat is a very good insurance policy that is SOP now, and well worth the minor expense. Yes, yes, yes, use ablative paint, unless you are sitting idle for long periods of time in an area with no water flow. Ablative wears away over time, so the crud does not stay adhered, and it continually exposes new copper to curb bottom growth and scum. When you repaint use a signal color that is different than your primary color. So in my case, I am doing the bottom this year actually, and I use dark blue paint. My signal coat will be red. Then I can tell when its really time to repaint. Another benefit of ablative is that you don't need to paint every year.

Yes, you can strip the bottom yourself instead. If you do, buy a full face respirator. Don't ###### around. Sorry for the salty language but I mean it. Also, use a sander that hooks up to a vacuum to catch the dust. This is not the words of some enviro freak, but someone who has had bottom paint in his eyes countless times, and it sucks. Even with that, and the full body tyvek suit, you will likely swear off this work within about an hour or two. Pay someone to blast the bottom. Seriously. Keep your boat fun, and pick the jobs where you will feel accomplishment. Don't be a martyr. Trust me on this one. This is a job that if you choose to pay someone, there is no shame at all.

Interlux also makes good paint. Don't discount West Marine brand. But I use Interlux Micron CSC with Biolux. Yep, its expensive. But it WORKS! And I don't have to worry about it. It takes me over a gallon to do my bottom. I guess it depends on the outside temp and how much you slap on. But buy two gallons for your final coat. You may not use it all, but if you seal the can well, it will last until next year which is good at nearly $200 a gallon!. STIR IT REALLY WELL. Don't paint your shafts with the bottom paint, or your props. There are other products specially for that. I don't use them. My boat is usually in from sometime in mid to end of may, until early to mid October in CT and I might get really small barnacles at worst case. Friends close to NYC have to do something because the water is so rich in "nutrients" that they cannot keep the crap from growing. I'm glad I don't dive there...

Almost forgot other questions... You strip the bottom when it starts coming off in sheets... You might get another year out of it, but given the cost of bottom paint, do you really want it all falling off? No. Best way to strip? Hire someone. Or a good light random orbital sander that is industrial in quality. No Northern tool stuff, ya hear? Like porter cable, Fein, or top end stuff. Its worth the extra money. And LIGHTWEIGHT as you will be holding this over your head the whole time. And you will take days... 45 grit. No higher than 60. And buy a lot of pads. You will go through a lot of sand paper. Bottom paint softens when it gets warm and abrasion usually warms things, so it gums up the sanding pads. you will use many. But not if you are paying someone else to soda blast. ;)

Environmentally friendly bottom paint? HAHAHAHAHAHAHAHAHAHAHAHAHA!!!!! WTF is that????

Good luck and ask away!!!!!

Dug