MacGregorSailors.com

Hello all,

My new (to me) Mac 26M has black anti-fouling bottom paint on. I do not know how the previous owner was using the boat - but the bottom paint is in decent condition.

But I will be storing the boat on the trailer in the storage. I will be a daysailer, or may be 3-4 days of cruising at max.


I've read in few places that bottom paint slows down the boat.

Should I remove the paint?
Will it come off cleanly? (most people removing the bottom paint is to re-apply them again, correct?)
If I pay someone to do it, what should I expect to pay?

It slows the boat, but not by much if it's clean.

If you remove it, expect to find the original gel coat was sanded rough to hold the epoxy barrier, and I don't know where you go from there other than to recoat with another barrier coat and ablative bottom paint.

If it were me, I'd just keep it as-is, and keep it clean. But that's just me.

If the color does not bother you, and you are concerned with speed, you can burnish the anti fouling paint by sanding it smoother with a light grit paper, like 120 grit. It will be work and you'll use a lot of sand paper. Try doing a spot on the bottom to see if the finish is worth the effort. Don't sand so hard that you go through the black.
With anti fouling paint applied to the boat bottom, The hit in speed is more noticeable running the engine at higher speeds. Maybe half a knot? Under sail it doesn't probably make a rats behind bit of different
Ix

Unless the paint has 1/4 high ridges or large protrusions leave it alone. If it looks good just be thankful you do not have to sand and repaint. We only repainted our boat because half the paint was gone before we started working on it. You could even see where barnacles had been attached. That black paint runs over $200 a gallon some as high as $275 per gallon. Just enjoy the boat.

Bottom paint may slow it a fraction under power, but not noticeably under sail. I'd leave it as the original gelcoat was rough-sanded. You may also find your usage changing or you may want to keep it in a slip summers eventually.

If you’re considering repainting buy an anti-fouling that works well for trailed boats buy a quart and test a small patch to check compatibility. You’ll just need to give it a light sanding to ensure a good bond and then paint (or have someone do it, but it’s really not that hard). With todays new paints there are very few old paints you can’t paint over. If it works you can just do a patch paint or really, really thin coat to brighten it up but will probably have no real benefit. I think the gallon I bought ended up being around $150 from interlux, can’t remember where I bought it though; I just went to interlux’s website and found a product that worked for my application and then googled it and found a distributor. Do some research and shop around. And IMO I wouldn’t be removing it, that’s three times the work to repaint it.

…and if you do at some time slip the boat, there will come a point early in the season beyond which the hull will actually be faster than otherwise, because of the reduced growth (and drag) that there will be as compared to an untreated bottom.

Agree, you could be potentially opening a can of worms if you start to refinish, which could be costly if you have to pay someone else to do the work, and do it properly. It would be nice if you could somehow find out exactly what the previous coat is, because with compatible materials often you can just paint over top of the old finish (with a little prep, like a light surface-smoothing sanding).

Thank you to all who replied.

I will leave the bottom paint as-is for now, as many of you suggested.
I don't know how I will use the boat really, so I'll just go along, until i know what I want for sure.

Thanks everyone.

Jason

More important than bottom paint is the barrier coat.Fresh water will permeate quicker than salt water through the gel coat.In regards to anti fouling,use a paint designed to dry out of the water if trailerd without losing its anti fouling capabilities. Not knowing what is on the boat would dictate removing the existing paint and verify the integrity of the barrier coat and then paint a minimum of 2 coats of anti fouling that is designed for your use.
Be Blessed
Ed Sabbath Day's

jasonsjwou wrote:Thank you to all who replied.

I will leave the bottom paint as-is for now, as many of you suggested.
I don't know how I will use the boat really, so I'll just go along, until i know what I want for sure.

Thanks everyone.

Jason

Sounds like a wise plan to me.

Ours had bottom paint and we just left it for three or four years until it had all worn away and looked horrible at which time I decided to redo it, - mainly because I wanted it to look nice again and redoing it is the easiest way to accomplish this when you have old antifoul.

When you get to that stage, you will save a bucket by doing it yourself and its not hard. The real work is in the sanding but the way to do that is with dryway sanding sheets. I used two sheets to do the whole bottom in a few hours. This stuff here:
http://www.onboardwithmarkcorke.com/on_ ... uling.html