Lots of bottom paint on potential boats

[josrulz]

Hi everyone,
I've read through the forum threads (many of them) under Gear and Maintenance about barrier coats, bottoms paints, etc., and I'm pretty clear on those topics in general.

My question has more to do with evaluating potential boats as my wife and I continue our boat search. Many of the boats we've looked at (most are 20+ years old) have many years of paint build-up on the bottom.

I'm trying to understand what we'd be getting into if we bought one of these boats with a very thick build-up of bottom paint (assuming no blister problem is apparent, which is another thread altogether). I have a few questions:

1. Would we need to do anything at all? I understand the boat would be slower with all that paint on it, but is it necessary to deal with it in the near term?

2. If we do address the paint build-up, is it "all or none"? In other words, is it basically a choice between stripping all the way down to gel coat, barrier coating and painting versus doing nothing? Or is there an "in between"?

I'm not trying to do something half-way, just want to know the reality while we continue our boat search. I wouldn't eliminate a boat because it had a heavy build-up of bottom paint--obviously that would cut out a LOT of boats. I just want to know what we'd need to do to deal with, if anything.

Thanks in advance...
-J

[camaraderie]

No need to remove the bottom paint immediately...just add more and go sailing if there are no blisters. Obviously, sooner or later all that paint should come off with a soda blasting...and at that time barrier coating with epoxy is a good idea but not crucial. Just ask the prior owner if the present paint is ablative or hard as you do not want to put hard over ablative as it will come off in sheets.

[xtatico1404]

Blisters aside, what needs to be done is directly related to the type of bottom paint on the boat. If it is ablative, then build up is not such a concern/problem, since it "wears" away over time, although some build up does happen. If it is ablative, then a nice power wash and a good scrub will do the trick "most" times. It's all going to depend on the PO's treatment of the issue.

If the paint is a hard paint, then that is a different thing all together, since build up is a matter of fact. I am sure other will go in detail of what needs to be done with hard paints, since I have not dealt with them so far.

[Stillraining]

As far as Im aware of they just had to stop selling the GOOD stuff...a few states like California are or are trying to pass laws banning existing applications of it also though...mostly because of in the water bottom cleaning...they are trying to put an end to that also...but most everywhere else and its grandfathered in on existing applications..just like ceasoted pilings still everywhere..No mater what paint you scrape off in a boat yard these days you have to contain...so there is no differance there..Any outlawed bottom paint covered by a modern approved one is accepted in all marinias I personally know of...besides that they arnt going to scrape off a sample and analyze it anyway so what they dont know wont hurt em..

[BarryL]

Hello,

A number of things can happen to a boat with a lot of paint build up.

1. Nothing bad may happen, just that the old paint is 'dead' because all the antifouling is worn off. If you don't add new paint, you will get a heavy marine grouth.

2. The old paint may get so thick that small or large sections flake off. In that case, repainting won't help much because the new paint will be attached to the old paint, which will still flake off.

3. The old paint is adding extra weight to the boat, which will decrease performance. As the boat sits in the water, the paint will absorb water and get heavier.

If the current paint is flaking off, you will need to remove all the old paint, then repaint. If you don't do this, the paint will continue to flake off. This won't really damage the boat, but won't help eather.

If the old paint isn't flaking off, you can remove it, or not. You can can do that at your leisure.

My current boat had a lot paint build it. The paint was flaking off and was in terrible condition. I had it soda blasted off, then I barrier coated it and then bottom painted it.

Barry

[josrulz]

Thanks for all the info everyone. I'm sure what we do will depend on the specific boat we end up buying. If it has a thick build-up of paint like many we've seen, I'll be sure to keep an eye out for the condition of the paint (flaking or still OK). Sounds like if it's not flaking, it's ok for a bit, but should probably be stripped within a season or so (perhaps next available winter). If it is flaking, then we should just fix it.

Of course, if we're going to bother with soda-blasting, we're going to barrier coat too.

Thanks again for all the advice. Now back to the boat search!
-J

[T37Chef]

Before you buy a boat with years of paint build up...please read this:

Our boat had a lot of paint build up when we purchased it. We had it surveyed by a "reputable surveyor"??? The hull showed "acceptable" to low moisture readings.

The following spring of ownership I had the hull blasted...only to show what you see in the photo below. Although the blisters were not deep, but about 5 the size of a nickel, it was still very upsetting to find out months after the purchase.

Knowing what I know now, I would have still made an offer on the boat, but a much lower offer, the equivalent of what a professional repair job would have cost or about $10,000 less.

My suggestion is if the boat you have chosen has a lot of paint build up it may be wise to ask the broker/owner if you can have a professional repair company take a few samples from the bottom and test for moisture and water damage, if they say no way, maybe they know something you don't???

BTW...my surveyor received a phone call from me after seeing what was present in the gel coat after the soda blaster did his work. He looked it over and offered his "professional opinion" on what was and what to do. I did not see the point in pursuing any legal action with the surveyor, I just wanted to get sailing, but I probably could have filed something with a good lawyer? My bad for not researching more before the purchase.

[josrulz]

Thanks T37Chef, I'll definitely keep that in mind. I realize that heavy paint build-up could be hiding something, whether known by the seller or not. I don't want those kind of surprises any more than you did, I'm sure. Sorry to hear about your experience, but at least you have your boat! We're still looking...
Thanks again,
J