Antifouling paint

[Judith and Paul]

We are about to enter salt water for the first time and will be spending 7 month in the water with several stops of at least one week. Then the boat will be on the trailer for the winter and back in salt water for 4-5 months.

What is the thinking and experience on bottom antifouling paint?

Much appreciate any input. Happy Thanksgiving!
Judith and Paul
Tranquilo

 

[Morning Star]

Judith and Paul,

We keep our boat in a saltwater wet slip most of the time, but have it on the trailer sometimes for extended periods. With this in mind, I chose Vivid antifouling paint (over an epoxy barrier coat). Vivid is a hard ablative paint that tolerates both wet storage and dry storage. So far, I have gotten two seasons out of the bottom job and I am happy with the antifouling performance.

 

[Judith and Paul]

Jim,

Thanks so much for the info.

 

[JamesTXSD]

We use Micron CSC Extra, an ablative paint. Also designed for boats that will be in and out of the water. We have been getting 2 to 3 years, with an occasional touch up in wear areas. Very pleased with the effectiveness and how it holds up. Applied over an epoxy barrier.

 

[roydawn]

I don't want to go too far off subject, but can some one expand on the need for an epoxy barrier coat on a trailerable boat? I did a 8 coat West barrier system on our 42 GB so I am familiar with back pain & how to mix/apply it. Just not sure of the need on a late model C-Dory. Roy

 

[Sunbeam]

Recognizing that the whole subject of barrier coats brings up a variety of opinions, but putting that aside: A trailerable boat can get just as much water exposure as a non-trailerable one does. That is, some folks keep them in slips, some just use them (so they're in the water) a lot, and some don't even have trailers (although that's unusual).

The more exposure to water (and the less "air time" to dry out), then the more time water pressure has a chance to "osmose" through the gelcoat.

I don't think anyone knows (or agrees) exactly at what point one would have "enough" air time to negate the possibility of blisters, but I bet high-speed trailering trips dry it out pretty well - if one takes those relatively regularly.

It's always seemed ironic to me that while the best place for a wooden boat to be is in the water, the best thing for a fiberglass (hull) is to be high and dry. Not that we can't get around that

 

[roydawn]

Sunbeam, I understand the irony, I had a '57 wooden Chris-Craft that had to stay damp/wet & a few FG boats that had to keep dry. I guess it truly depends on HOW much time the C-Dory spends IN the water. I avoided a C-D that stayed in the water it's whole life [6 yrs. & owner didn't want a survey done]. But I didn't think blisters wee a BIG problem on C-Dories. May rethink that. Roy

 

[Rob & Karen]

I avoided a C-D that stayed in the water it's whole life [6 yrs. & owner didn't want a survey done].

That's interesting. What did the owner say about a survey? I can't imagine saying "my boat is for sale but you cannot have it surveyed". Could there be any bigger red flag than that?

Rob

 

[Sunbeam]

Sunbeam, I understand the irony, I had a '57 wooden Chris-Craft...

That must have been sweet!

I avoided a C-D that stayed in the water it's whole life...

I also looked for one that had not been kept in the water and still had the "bare" gelcoat. First of all, I figured that I probably will be in and out of the water enough that I won't need/want to paint the bottom. Second, I wanted to be able to see what was there. Third, if I do decide to bottom paint, I want to know exactly what/how is done myself.

I noted that El and Bill's boat Halcyon still had the original bottom gelcoat when she was for sale last year - and they did a lot of boating/living aboard over a decade+ of ownership. I don't believe they ever had any blister problems, either. My guess is that they hauled/trailered often enough to keep the bottom clean (by hauling soon enough to clean any accumulation) and dry (highway wind).

Of course blisters seem to be a bit inconsistent from boat to boat and locale to locale. And there is no absolute guarantee with barrier coat. Still, I think I would barrier coat if I were to bottom paint, reasoning that having to bottom paint would mean I was spending "that much" time in the water between hauls/trailers.

 

[Captains Cat]

There was a funny article in WoodenBoat a number of years ago about having to "sheath" a fiberglass boat with wood to prevent blisters... It followed an article about having to fiberglass a wooden boat to prevent worm invasions... :lol: Wish I'd kept it.

Charlie

 

[Jack in Alaska]

I would like to remove all of my bottom paint permanently.
How to do that at a reasonable cost.?? I want the bottom clean and white again. It is a mess right now in that the some of it is peeling off in large areas leaving a real messy looking bottom. The paint was on the boat when I purchased it.
Sand blast??? Some kind of chemical removal?? What???

 

[Sunbeam]

I would like to remove all of my bottom paint permanently.
How to do that at a reasonable cost.?? ...
Sand blast??? Some kind of chemical removal?? What???

I have been involved with soda blasting a few boats. Typically the plan is to re-paint, and the surface that is left is not shiny/new gelcoat, but more of a matte finish with all-over very small pock marks. I don't know if that can be varied or not. I think actual sand blasting would be too harsh.

A carbide scraper can work really well to remove bottom paint, but you may end up with some "divots." (I've never scraped bottom paint from a boat that I was trying to bring back to gelcoat; only ones that were going to be re-painted.)

I have read of people using "Peel Away" (a stripper that you put on with plastic) and also other strippers (soy strip), although I have not used them to remove bottom paint myself. I did use some Interlux paint stripper on paint in a bilge and it actually began to affect the fiberglass (heavy application), so at least that one deserves respect. My guess would be that stripper would be the most likely to leave a "nice" finish.

Sunbeam

 

[rogerar]

I took off 13 seasons of bottom paint-really thick! with Peel Away last year.
It wasn't exactly fun, but the Peel Away works great, it took two 5 gallon buckets of the stuff.
It came off right down to the gelcoat, which was in great shape.
I used cardboard to catch the paint, then pressure washed clean.
Roger

 

[Will-C]

Some folks do not choose to use an epoxy barrier coat before adding bottom paint. Epoxy barrier coat has been recommended by folks on this site with a lot of boating experience as an extra level of protection. Since it can't hurt as I see it (except your wallet), I would have the epoxy barrier coat added before the bottom paint if I was going to add bottom paint our boat. Your boat your choice.
D.D.

 

[Matt Gurnsey]

In theory, late model C-Dory's with Vinylester Resin should not need a barrier coat. And in nearly 30 years of bottom painting boats without a barrier coat, we rarely see blisters in our area.

I have seen some discussion of barrier coats trapping existing moisture in the hull and creating blisters. This would happen on used vessels, not on new.

Areas of warm salt water tend to have greater issues with blistering, and a barrier coat may be beneficial in those climates.

Most of the yards in our area don't recommend barrior coating, other areas of teh country it's an automatic part of bottom painting. Certainly a boat yard can make more money by barrior coating as there is additional cost in materials and time, so from a pure profit standpoint, it would be a good thing to push. If we felt it worthwhile, we would recommend it. For those that want it, we will certainly do it.

That being said- I see very little down side to doing it, other than time and expense.

 

[Sunbeam]

In theory, late model C-Dory's with Vinylester Resin should not need a barrier coat. ]/quote]

Can you say when C-Dory switched to Vinylester resin? I would consider that a plus, since it's considerably less permeable than polyester.

Areas of warm salt water tend to have greater issues with blistering, and a barrier coat may be beneficial in those climates.

Although I've also seen quite a few blistered Great Lakes boats, which would seem to defy the "rules" (i.e. it's cold water, fresh water, and those boats are hauled for ~6 months of the year).

If someone wants to barrier coat an existing hull, it's possible to get an indication of the moisture content with a meter (conveniently, they work better on non-bottom-painted surfaces).

 

[Sea Wolf]

I would like to remove all of my bottom paint permanently.
How to do that at a reasonable cost.?? I want the bottom clean and white again. It is a mess right now in that the some of it is peeling off in large areas leaving a real messy looking bottom. The paint was on the boat when I purchased it.
Sand blast??? Some kind of chemical removal?? What???

Jack- The easiest way to get it off would be to use a chemical stripper, like Jasco's Strip-Eze.

However, I'd call Jasco's Technical Representative and find out if it can work without harming the fiberglass.

Next problem is the fact that the gel coat has probably been sanded with a machine sander to get adhesion for the barrier coat and/or anti-fouling paint.

If it hasn't been sanded, getting the a-f paint off cleanly may get you home free.

If it has, you'll have to paint it again, unless the stripper can remove the a-f paint, but leave the barrier coat, and that coat is smooth already, which is even less likely.

Might just be easier to sand it down good and apply a coat of hard anti-fouling paint that will last a considerable length of time and look good for several years.

Proverbial Can of Worms, for sure!

Joe. :teeth :thup

 

[Sunbeam]

Proverbial Can of Worms, for sure!

True, but... it sounds like the paint is failing already, so to my mind getting that off is simply the thing to do before assessing what to do next (either way).

I think I would start by using a stripper in a small area, so you can see what you have. If your paint is coming off in hunks, then you may have "lucked out" in that whomever painted the boat in the first place didn't prep it well (I have often seen a failure to properly remove mold-release wax, which causes adhesion problems).

If you were trying to save a barrier coat, well then some strippers would harm it and some wouldn't; but if I were you right now I'd just plan on going back to gelcoat, and then proceeding from there -- even if you do re-paint and/or barrier coat. Many times the millage (thickness) of the barrier coat is inadequate anyway, from what I've seen.

I know of two people who have used Franmar's Soystrip to remove quite a bit of bottom paint from a "larger" boat (~30' sailboat). They had good things to say about it. I did call them once to ask about whether it would harm a barrier coat and they said they wouldn't recommend it in that case, but I don't think that's a concern for you (if you're going back to gelcoat). It sounded a lot more pleasant to work with than something like the Interlux stripper (and other more typical ones) I used.

The Peel Away also sounds good, although not cheap (you mentioned cheap, IIRC). I've also read that you probably have to use more, and let it sit longer, than they might lead you to believe. Still, it sounds like a good way to go, as it more-or-less does the work for you, and everything kind of falls onto a ground tarp. They do have one that is "safe" for barrier coats, but the reports I've read have been for the "original" flavor.

Even if your gelcoat is sanded, it may not be a problem to stay with bare gelcoat. I'm pretty sure some racers purposely wetsand their gelcoat, because the "boundary layer" (or whatever you call it, anyway, the hydrodynamics) is less draggy. In other words, a perfectly smooth or waxed boat is actually slower than one that is slightly rough (but rough in a smooth way, not rough in a "fifteen ragged coats of old bottom paint" way). (Note that I don't think it's a huge difference, but enough of one that racers don't wax, but instead sand.) (I've read that if one's car were pocked more like a golf ball it would lead to better gas mileage, but then the aesthetics might not be pleasing.)

So, presuming you have enough thickness left in the gelcoat (i.e. no-one mangled it when paint prepping), you could still sand it smooth with successively finer grits of wet-sanding paper.

If I had to guess, I'd say (hope) that your failing paint indicates a lack of thoroughness in prepping, which may mean that your gelcoat is in decent condition. Hey, it's not too often you hope a job done prior to your ownership was not done up to par

Sunbeam

 

[Judith and Paul]

Here is what Dog River Marina Boat Works, Mobile, Alabama, is recommending and doing:

Since we will be in salt water for 7 months, then on the trailer for winter storage (unless we go to Baja and the Sea of Cortez), then back in salt water in the Pacific NW, we cannot take the boat out of the water often enough to keep it clean. Also we want to be able to stay in one spot for several weeks in a few places in FL.

They are roughing up the gel coat with a fine grit sander at a slow rpm. Then they are putting on an epoxy barrier coat (which they usually do not do anymore) for extra protection and another reason which I cannot remember at this moment. Then they will put on a blue first coat with a second black coat. We requested a third coat, black, be added. The barrier coat is Interlux 2000E and the ablative black coat is Interlux Micron Extra. This paint tolerates both wet and dry storage. We should get several years of use before it wears off.

We have enjoyed the conversation. Thank you all for your input.
Judith and Paul
Tranquilo

 

[Sunbeam]

Here is what Dog River Marina Boat Works, Mobile, Alabama, is recommending and doing:

It sounds like you are set with a good plan, so I hope you don't mind if I add a couple of thoughts.

They are roughing up the gel coat with a fine grit sander at a slow rpm.

They may already be planning this, but it's really important to carefully remove the mold-release wax before sanding. (And this holds true for 30-year-old boats as well as new ones, as the wax doesn't "go away" with time.) Typically one uses a solvent such as Interlux 202, and then a technique where you do it in small sections, wiping the 202 on with one cloth, and then immediately wiping it off with a clean cloth (and this second cloth has to be tossed/replaced for each swipe, or you just re-contaminate).

Then they are putting on an epoxy barrier coat (which they usually do not do anymore) for extra protection and another reason which I cannot remember at this moment.

The "another reason" may be that Interprotect makes a good chemical tie coat. That is, the Interprotect sticks really well as a primer, and then if the subsequent paint coats are put on within the proper time windows, they chemically bond to each other, which is a good thing. One note is that as a tie coat only a minimal thickness is needed (say, two coats); but for it to perform properly as a barrier coat it needs to be thicker. Interprotect will specify the "millage" needed (i.e. thickness). I am not current on this (and it changes from time to time as they refine things), but in the past it would typically have been around five coats for barrier protection (the thickness is achieved with multiple thin coats not one thick one).

Then they will put on a blue first coat with a second black coat. We requested a third coat, black, be added.

The blue indicator coat is a good idea - I would do the same.

While my experience with it is on non-trailerable boats, I've found Micron Extra to be a good paint in general. It's often used in the mid-Atlantic, which is reasonably high-fouling territory. What I don't know is whether I would choose it for trailering and/or for sitting in one place for an extended time (but I might; I just haven't done the research for that application). The two possible compromises I can think of (vs. a harder paint) are that it may rub off on the bunks, you, tie down straps, etc. (since it's soft); and that it likes to be kept moving in order to ablate and do its job. Sometimes for boats that knew they would be sitting in the slip a lot I have used slightly harder paints (although I've always used the Pettit equivalent to Micron Extra on my own bottom-painted boats - but they were not trailerable or sitting still for very long at a time).

I'd love to hear any experienced trailer-boaters' comments on how the soft/ablative does when trailering. Is it a pain and coming off on everything? Or is that not an issue.

I hope this is not "too much information" after you have already decided on a plan

Sunbeam :hot