Bottom painting

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Ron
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Bottom painting

Post by Ron »

Maciek -

In theory your right. The epoxy based Interlux Fiberglass Bottomkote is not the right paint for hauling and launching over and over again. But in your case with minimum time in the water it won't really matter. It takes a couple of days for both the hard and soft growth to occur. The warmer the water the quicker it happens, and as I recall, you're somewhere up in the Pacific NW where the water is anything but warm. You can probaby do 5 to 7 days with zero or minimal growth, and then easily powerwash any of it off of the hull.

Considering your need to dry store the boat, I would probably go with an ablative next spring. But get one that is "scrubbable". Some of them easily wash off but others can take some abuse, including being rubbed by the trailers bunks when you launch and retrieve. The hard paints can do this as well, but most of them cannot tolerate being out of the water for any period of time before they lose nearly all of their ability to fight off the growth. The air tends to seal off the outer layer and traps the copper.

I've used Petit Hydrocoat for about 15 years on several boats. I happen to like it, but it may not be the best paint for everyone. For example - it would not be the best choice for tropical climates where the boat stays in the water. For the Telstar I have a lift down in Florida for the winter (boat is on the lift maybe half of the time) and I keep the boat in the water in NJ during the summer. On the other boats I stayed wet up in the Northeast for 2 years at a time with this paint with very good results. It is scrubbable, can be launched and hauled over and over again, will resist being rubbed off by the bunks or by beaching the boat, is water based so cleanup is easy, and is relatively inexpensive as compared to other paints. It also contains teflon and if you lightly burnish the paint when it drys (3M pad or similar on an orbital polisher) it looks more like a teflon frying pan. On a big monohull it was probably worth about 1/4 to 1/3 of a knot of boat speed.
Ron Marcuse
Telstar 28 #359 "Tri-Power"
drsm
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Bottom painting

Post by drsm »

Buen Tiempo had been painted at the factory last winter and wasn't launched until early June in Lake Michigan. She's been on a mooring since then. The bottom coat did very little to deter slime in our cold fresh water. I also did battle with a lot of Zebra mussel growth, but primarily in the through-hulls and around the centerboard trunk.

I'm having her hauled in a couple weeks and am considering having a barrier coat applied, then an ablative (they use a lot of VC-17 around here).

Steve
Ron
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Bottom painting

Post by Ron »

Steve -

The original epoxy based bottom paint has to get into the water within 60 days, and is not really suitable for re-launch months later. PC probably dropped it into the water when it was finished to make sure there were no leaks - it could have been before, during or after the winter. In any of these cases you would have been left with a paint that may have been unusable by that time - either more than 60 days or exposure to air.

VC17 is a good paint for fresh water. It's a thin film teflon. But note that you may have to remove the epoxy based paint you've got already and you better check with Interlux to make sure that you can re-launch (if that's applicable in your case). I think it's classified as a hard one-season paint, with 2 or 3 coats needed - and you have to get the boat into the water rather quickly (and leave it there).
Ron Marcuse
Telstar 28 #359 "Tri-Power"
seicam
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Bottom painting

Post by seicam »

How about an option of removing the paint completely and leaving the bare bottom with no paint? Of course this would be for boats like mine that sit most of the time on trailer. There is about 20 other boats in my dry moorage area, including about 4 Corsairs, and most of them do not seem to have any bottom paint.

Regards,
Maciek
Ron
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Bottom painting

Post by Ron »

Maciek -

A boat sitting on a trailer does not really need bottom paint. It sole purpose is to stop growth on the hull, and will do absolutely nothing to keep moisture out of the gel coat. And exposure to air (e.g. - on the trailer) is the most effective way to stop moisture from getting in.

The question is how long will it stay in the water when you launch it? I've got a 20 foot jet boat that sits on a lift or on it's trailer virtually all of the time. No paint needed. But I can't really leave it in the water for more than a few days at a time down in Florida. I left it in the warm water once for about 6 or 7 days during the "winter" and wound up having to scrape / power wash off a bunch of barnacles. The much colder water up in your area could give you more time. I'm probably limited to around 3 or 4 days down there in the winter, less in the summer . Also - the problem gets much worse when the boat just sits at the dock. If I got the jet boat up to 60 knots every other day then the barnacles would never have a chance to grab on - they'd be blown off by the water rushing by. Even 8 to 10 knots would help.
Ron Marcuse
Telstar 28 #359 "Tri-Power"
seicam
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Bottom painting

Post by seicam »

This is my first boat, so it is all hard to say. From what I hear from other sailors around here it usually takes at least a week for any growth to start occurring. This and next year I doubt I will take trips longer than a week. Most likely I will be taking many shorter 2-3 day trips and maybe one 1-week outing. I'm still learning all the ropes :-)

I guess the question for me is what is more cost and labor effective solution, in the long term, out of the three possible ones I see:
1) Strip the current Bottomkote paint and leave the bare hull.
2) Strip the current Bottomkote paint and apply new barrier coat + new ablative paint (like Hydrocoat)
3) Apply new ablative paint on top of the current Bottomkote

I do not mind spending some extra time and effort on the boat next spring to do this stuff, as long as I do not have to repeat this every year.
Would keeping the boat out of the water have a (positive) effect on the longevity of an ablative paint?

Thanks,
Maciek
Ron
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Bottom painting

Post by Ron »

Maciek -

With your limited exposure to the water, just about any plan would work - including no paint at all. But I wouldn't paint over the epoxy layer unless it's in good condition, and even then I'd lightly sand it first. And because of the frequent exposure to air, an ablative is just about the only paint you can use. It should last even longer with the boat out of the water most of the time. I put 2 1/2 coats (an extra coat on the waterline, centerboard and rudder) on 2 years ago, lightly went over those 3 areas last year (mostly because I had some paint left over), and probably won't do the whole job again for another 2 or 3 years. My boat, at least during the winter, is in the water just about the same as yours. I'll find out what the bottom looks like in about 3 weeks when I pull it. It's been wet up here in NJ for about 5 months now. The water in Barnegat Bay is brackish - a mixture of salt and fresh. I'm expecting the Hydrocoat to be in good shape still.
Ron Marcuse
Telstar 28 #359 "Tri-Power"
Jerry
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Bottom painting

Post by Jerry »

I hate to re-open this topic but I just got off the phone with the boat yard and I have a couple questions I can not find the answers for here. I am planning to have the existing bottom paint stripped, barrier cote put on and new bottom paint. While I was going to do this myself I think I am getting wiser and figure it is a better yard job.

Questions:

1, judy7clark mentioned getting the boat off the trailer but it looks like it was still somewhat supported on the main hull. The yard is very interested in getting the entire bottom free so they can paint it all at once. Has anyone successfully done this? If I missed something in another post please let me know where to look.

2, The yard asked if the boat was built with "Vinal ester" epoxy and gel coat. Their comment is that it is much less likely to have blister problems if it was. The question is probably really academic to me since I have decided to get the barrier coat due to the issues I have read here. I would rather have the protection and stop worrying but I though I would try to answer their question.

3, On barrier coat should all three hulls be done or is the manufacturing process with the ama's such that they do not need it?

4, Remembering I am in fresh water has anyone had experience with Interlux Micron bottom paint? The yard initially though of VC 17 but stated it would be a whole separate process to sand the barrier coat perfectly flat since VC17 goes on so thin it does not hide anything. The sanding would also obviously take some of the barrier coat off.

5, I see people have raised their waterlines. I have not added any weight yet nor do I plan any major modifications so I was wondering if I should just raise it 1"?

Thanks in advance - snow is still falling - Arghhhhh

Jerry
drsm
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Bottom painting

Post by drsm »

Jerry,

We had Buen Tiempo's hulls stripped down and bottom coated this winter at the marina. We are in fresh water as well, and chose to have the Interlux 2000E sealant applied then VC-17. I'm hoping to head over there this weekend to inspect the results. The marina used their slings to lift the boat off the trailer to gain access to the whole bottom. We had all three hulls done. We did not have the waterline raised.

Steve
Jerry
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Bottom painting

Post by Jerry »

Steve,
Did they use the slings just to raise the boat so they could paint where it had been on the trailer or did they find a way to support the boat so they could paint the entire main hull in one operation? The later is what my marina wants to do if I can find a way someone has successfully supported the boat with the hull clean for a single application.
Thanks
Jerry
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