Salt water bottom paint advice

[Mike & Heather]

Hi all, Happy New Year!

My 2010 R29, Tug Time!, was just hauled out in Bellingham WA for a bottom inspection and new bottom paint. The bottom paint is blistering and upon further inspection there was no barrier coating between the gel coat and the bottom paint when it was originally applied. SInce I bought the boat used last year I am not familiar with the history. My understanding is that usually several coats of barrier coating are applied before the anti fouling bottom paint is put on the boat and that bottom paint is not applied directly to the gel coat. I am looking at having to sandblast off the old bottom paint since it is blistering before I can put on any new coatings

My questions to the forum:
-Is a barrier coating common?
-Have other owners had this applied at the factory?
-Is it common to put the bottom coat on directly to the gel coat w/o a barrier coating? Have others had blistering problems?

Thanks

 

[abcandjrc]

It is possible that your paint is peeling because the mold release had not been thoroughly removed before painting, or that dust was present on the hull when the paint was applied.

The vast majority of boats have the bottom paint put directly on the gel coat. In a well constructed hull, very little is gained by putting on a barrier coat.

Be extremely cautious of sand blasting a hull. It requires extreme finesse to remove the paint without damaging the gel coat.

Be extremely cautious of chemical peels, too. We had a blister-free hull for years. The boat was constructed in 1973 and was 26 years old at the time and transitioned between salt and fresh water regularly. It had many coats of bottom paint over the years which had built up in some areas. The yard recommended a chemical paint remover prior to application of new bottom paint. The next time we hauled, we had hundreds of significant blisters, many in the 2" diameter size, some as large as 6", and all were through to the structural FRP and full of nasty liquid. I was suspicious of the peel but had no real reason to make an accusation but did question the yard if the peel could have been part of the problem. A few months later, we saw them doing another peel job. They left the chemical on for the prescribed time, scraped off the paint, and then washed down the hull with high-pressure water and scrub brushes. They had not done the wash-down with ours but just went home after scraping off the paint since it was "closing time". I am 99.9% convinced that the peel worked its way through the gel coat and aided and abeted the creation of blisters. If you do consider a peel, read the directions yourself, and make certain that the applicator follows the instructions precisely.

I would recommend removing the paint the old-fashioned way. Sanding. It is more controlable, and also leaves a slightly rough surface giving the new paint better adhesion. Be certain to wash the hull and make sure the surface is dry and all dust is removed before applying the paint. If applying more than one coat, sand lightly between coats and prep again as in the previousl sentence

I also prefer application methods in the following order: Brushing; Rolling; Spraying. The more mechanical action in the application, the better the adhesion. You trade effort for (potential) improvement in performance.

 

[LADYBUG TOO]

I am a big fan of barrier coats; however, I do live in Florida and marine growth is pure hell here. My 2009 R-29, Ladybug, Too, has SeaHawk barrier coating with SeaHawk Cucote. So far it has worked quite well. My older boat had 5 coats of Interprotect 2000 topped with ablative bottom coats that I applied every two years. The boat was moored in salt water year round. I agree with the previous post in that I would not sandblast. It would require quite the touch to avoid damage to the gel coat.

Pat, Ladybug Too

 

[SlackwaterJack]

Perhaps I'm just a bit too sensistive to "boatyard B. S." ...but I get a strong feeling of "buyer beware" from this one.

1) I can't imagine ever recommending sand blasting to remove anti-fouling paint. Gel coat damage would be inevitable, not to mention the excessive toxins getting blown all over that would be a real problem.

2) A "barrier coat" isn't always found under bottom paint especially with vinylester hulls in "cold water" regions. From your description, they seem to be attempting to equate some peeling anti-fouling paint with osmotic hull blisters.

I'm not you, but if I was I'd pick up the phone and call the factory (it's close by) and see if they'd go to the yard and look at the "blistering" problem, or at least have them talk to the boatyard.

 

[abcandjrc]

Actually SwJ, the post didn't say the bottom itself was blistering, but the paint. Although I don't know what the full conversation might have sounded like or what it implied. That is one reason I suspected improper hull prep before the paint went on.

But I sure agree with you that much yard-talk is like doctors' insistence in my young years that tonsils had to come out any time a kid had a sore throat. Sometimes they did, sometimes they didn't. The good thing is that most of the time, it didn't hurt (except that it hurt and you always found out what liars your parents were with that "all the ice cream you can eat" crap). The advantage to the yards is a bit different in that the "latest and greatest" often take less effort, encourage a casual attitude in their use, and raise more revenue. A win-win for the yard, and often a loser for the owner (as in our case). Our experience with boat yards is a mixed bag. One has to ask around and pick with care to improve his odds of finding the right one.

We were hit by two other boats during Hurricane Opel and sustained $40,000 in damage. We enquired of our trusted suppliers and of our insurance company and came up with two on the Gulf Coast from Mobile to Key West whose names popped up on the list of everyone we asked. We had a better looking boat when it came out of the yard than when it left the factory, and it was built by a builder with a sterling reputation to begin with.

 

[TonyM]

Hi all, Happy New Year!
Who did did your bottom paint?
As was previously mentioned it sounds like that maybe all the mold release was not sanded off.
The Factory installed my bottom paint during construction.They told me that a barrier paint was not needed because it was incorporated into hull during the lay-up process.
I would go back to the installer...in our waters a good bottom paint should last about two years of a boat living in the water.

Good Luck
Tony Marshall
Molly M- 2010 R-25 SC

 

[mspaugy]

I would never sandblast fiberglass regardless of what it is coated with. I agree with the post that recommended sanding. Paint never stands up to the test of time and elements unless the prep work is done properly.

 

[SlackwaterJack]

My concern was with what the yard implied by using the term "blisters" and then mentioning a lack of barrier coat. The yard's remarks may have resulted in an un-neccessary (and damaging) sandblast and barrier coating(s) at considerable expense by causing some to infer that there was an osmosis blister problem rather than an anti-fouling adhesion failure normally corrected by the regular water blast, sand, wipedown, prep process. That a yard would recommend sandblasting gave me a chill.
I also noted that the owner is in California and "just hauled out in Bellingham WA " so they may be trying to deal with the haulout at a distance and may be at a disadvantage in dealing with the yard, so I recommended calling the factory. I'd offer to be his "eyes" but I'm 370 miles away and heading to Florida on Thursday.

 

[doke01]

He did state the paint was blistering, not the gel coat. These are two totally different things with the latter being very serious and the prior not so much.

 

[Andrew Custis]

Hello Mike,

Ranger Tugs has never applied a barrier coat to any vessel unless specifically asked to do so by the customer. A barrier coat is typically used on a polyester resin based hull. We use vinylester. Because the bottom paint is peeling which I think you meant to say rather than blistering, I would not be surprised of this at all being that I personally delivered that boat in late 2009. This means that the paint (if original) is well over two years old. I dont want to get involved on saying how to bottom paint the boat but I have never heard of sand blasting the old paint off.

 

[rt11002003]

I've read several articles recommending soda blasting to remove old bottom paint.

gene

 

[RProffer]

I am not an expert in applying paint, but I have painted lots of things such as cars, houses, airplanes, boats, etc., etc. One thing I have learned is the key to a proper paint job is preparation. And the way to learn to properly prep is to follow the instructions on the label. The manufacturer of the paint is the expert and I would follow their instructions explicitly. They know how their paint works best.

I do not remember the details, but I remember Interlux had one set of instructions for applying their bottom paint on a new hull, and another set of instructions for applying over old paint. Old bottom paint will flake off after a while. You should use a pressure washer to clean the old paint and remove any loose paint. Then use a scrapper to remove additional loose paint. If you want it to look pretty, then use sandpaper or an orbital sander to feather out any rough edges of paint. Then clean with specified solvent. Then apply primer/paint per the instructions.

ALWAYS use a respirator and goggles/face shield when cleaning and painting a bottom. You don't want that crud in your lungs and eyes.

 

[assignment]

Mike and Heather. I had a bottom job done on our R-29 earlier this year. PM me if you want some detail.
//Bud

 

[JerryE]

I've got Sea Hawk Tropikote on my bottom (the boat, not me) and nothing grows on it or (I suspect) near it in the water. This includes Florida and New England. Of course, the stuff is over 75% copper so it is pretty nasty.

Here's a cool option for a new clear product you can spray over the metal parts as well as the bottom on a new boat which is supposed to last for five years. In fact, this utube video shows it being applied to an R27:

[youtube]http://www.youtube.com/watch?v=_k0pFAEPnfo[/youtube]

 

[Favunclerich]

The video is impressive, but this thread at Sailing Anarchy leaves me less confident about its ability;

http://forums.sailinganarchy.com/index. ... pic=126103

I also looked at the manufacturer's brochure;

http://www.evolutionsurfaces.com/sell_s ... _Sheet.pdf

As an engineer, I noted that the test pictures in the brochure do not show a control sample. A well-planned scientific evaluation should have at least two comparison samples; one with no coating at all and at least one more with traditional anti-fouling paint.

Perhaps this is good stuff for underwater metal parts (with the exception of zincs), but I'm not ready to apply it to my fiberglass until some of these issues are resolved.

 

[Lobo]

Bottom paint and anti fouling. What a wonderful topic. My thought is no matter what you do it will be (a) a lot of work (b) a lot of cash and (c) repeat repeatedly. I don't think there is a silver bullet out there.

However, I notice one previous comment on the "boat bag". There are at least 3 sailboat racers using them in my yacht club here in Victoria BC and they work! It's a large bag with a "door" at the end. You open it up before you depart and close it up when you get back. A swimming pool chlorine container -- with chlorine -- hangs in it and this is enough to discourage the little creatures from adhering to your beloved hull. You can see them at

http://www.clearmarine.com/index.php.

Clear Marine is a local company. The last I heard was from an owner of a 25' sailboat that he expected 3 or more years and the cost was around $3,500 -- but that was a couple of years ago -- however I think his bag is still in good condition. Boats in these bags have had nothing done to their underwater gel coat and are active in our racing fleet with nice clean hulls all the time. Bags for power boats don't need the draft that sailboats require.


Dave
"Lobo"

 

[rwetjen]

Washington state has banned copper in bottom paint beginning in about two years. I think there are a few states where copper is already illegal. Does anyone have experience/recommendation for a good alternative? I've always used the highest copper content paint available with good results. This ban is taking me into new unfamiliar territory.

 

[Lobo]

I refer you to yachtpaint.com, the web site for Interlux paint. Under documents, open "boat painting guide". This is a comprehensive outline of marine paints -- obviously all Interlux -- but also has lots of other good information. Antifouling paints are near the end of the guide.

For about 10+ years, on my R-25 (coming up to 4 years) and my former sailboat, I use "Bottomkote XXX".

In 2008 when I bought the boat the dealer put XXX on. In 2010 I did a reapply of three coats. I lift the boat out of the water every (approx) 4 months to pressure wash the bottom and check paint and zincs. I'm now 18 months from the 3-coat reapply in 2010 and the paint is holding up very well. I plan on redoing the hull again in June 2012. I'll apply XXX again, probably 3 coats, with 4 along the waterline area. This will take around 1 1/2 gallons. I now use the 4" sponge rollers and am very happy with the results. I leave the boat in the water all the time.

The dealer put red XXX on during commissioning. I put blue on in 2010. If I see the red coming through the blue, I know that I've gone through the blue.

Hope this is some help to you.

Dave
"Lobo"

 

[abcandjrc]

.........The dealer put red XXX on during commissioning. I put blue on in 2010. If I see the red coming through the blue, I know that I've gone through the blue.......

This is a good idea that we used on our two cruising boats. Sometimes it is difficult deciding on a couple of colors that don't offend overall appearance (one advantage of white topsides) but this is as good an indication of recoat-time as you will find other than a full coating of barnacles.