Bottom Paint

[CaptainJohn]

Hello!  I have a 1989 Compac 23 that has not seen the water for about 7 years.  When I purchased the boat there was fiberglass work done below the water line.  The entire bottom was stripped and sanded.  I found out the yard did not put a primer on the bare glass and used 2 coats of Pettitte unipoxy.  I haven't had blister issues but there is minor flaking in certain areas which I would think is normal.  The boat is in NJ and in the water 5 months, out 7.  Question - before I put the boat back in the water next spring, should I just spot prime and use another coat of unipoxy or do something more proactive?

[skip1930]

How deep are your pockets? I'm a bloke of limited means.

Salt or fresh? Sounds like salt.
Pockets are shallow so I use waterbase latex house paint from Ace Hardware with a couple layers of wax on top of the paint.
Some times a quart, sometimes a splash more for my CP-19.

One time in at the beginning of the season and once out at the end. No grass in fresh water.
I actually grow grass on my IdaSalor rudder but I won't paint that. Just wax it also.
At end of season over to the car wash for a spray wash and $10.00 worth of quarters cleans her up.

Sounds like you want it done right so I'm guessing big money and not any swill will do.
Sorry I can't advise.

skip.

[Craig]

Short of stripping all over again,based on your info, spot priming and repaint would be the most cost/labor effective. If the bottom was sanded, the primer is less of an issue if for the most part the paint is adhering well. Even with the most careful prep, some flaking may occur. One has to weigh the trauma to the fiberglass that stripping/sanding causes against what you will be gaining. I am sure that some will recommend a total bottom job as the "best" course of action and in a world where labor and money are no object(Tiger Woods reportedly just spent $1.7 mil   to have his yacht totally repainted from the keel up!)that is true. But as for the rest of us  sailors of moderate means, we must weigh the real cost/benefit options of any serious hull projects.  

[Bob23]

Hi John.
   I'm also a 23 owner in NJ. Where in the Garden State are you? Back to your question:
If you have no blisters and the paint is just flaking off in spots, why not just spot prime and repaint over those areas? I'm in the same boat (pun! Hahaha). My 23 really is ready for a soda blasting, epoxy barrier coat and bottom paint job. The problem? Available funds.
   This spring, before launching, I did the spot prime job described above, and a total coat of Interlux Aqua water based bottom paint. I'd been using Pettit Hydrocoat but I think they changed the formulation as my recent coats didn't hold up as well as the old stuff. So now I'm giving Interlux a shot. I really like the water based paints...dry fast, hardly any odor, cleans up easy and, most importantly- it works! I'll find out how well in a month when Koinonia (1985 23/2) is hauled.
   Bob23 in Southern Ocean County, NJ. Barnegat Bay. Home port: Surf City.

[brackish]

I'm confused.  There is no need to prime bare fiberglass before application of Unepoxy.  It calls for the surface to be properly prepared by sanding/dewaxing.  If the yard followed that procedure then you would be wasting money to strip it off and start over.

On the other hand if you are confusing "priming" with the application of a barrier coat then that is another story.  The barrier coat is strictly to reduce the possibility of osmotic blistering, has nothing to do with the adherence of Unepoxy or any other bottom paint that has as its purpose the reduction of marine growth on the bottom. 

So the choice is yours, however I would opt for the minor maintenance if you are out 7 months at a time.  If you see blisters start to develop on any season ending haulout, you will always have the option of repairing them and doing the barrier coat at that time. 

[MacGyver]

IF it was done over bare fiberglass then your yard is a bunch of morons.
I can say that because of where I work and my record as a boat repairman specializing in bottom work on cruisers to race boats.

I feel the product called Interlux 2000 is the best primer (barrier coat) for the money and the best at working with the customer who cant be there for every coat every day (up to 6 months between coats except for the last to the first coat of bottom paint.)

To be honest, the times I have used Pettit Protect, well, you couldnt give me a can of that to use on my own boat let alone a customers.

I know very little about there unepoxy product.
I communicate regularly with our Interlux Rep and the Pettit Rep. The Pettit guy has been trying to get me to switch to his stuff for about 12 years.

At any rate, without seeing the bottom in some fashion, I can only say what the first sentance of the post was and also that you should inform yourself with the products that go on your boat. Blisters can be damaging if not treated properly. And a bottom can be damaged if not treated properly.

On my 19 when I got it, she went in the water with what she came with for a few months. Came out and the start of this year got a full bottom job which included 2.5 gallons of Interlux 2000 and Fiberglass bottomkote blue.
That in turn should be about 3 to 5 years. That will then need a sanding, and reapplication of the bottomkote, not the 2000.

A good job will show no signs of flaking, etc as the paint is supposed to wear off over time somewhat, except the ablatives, they literally will spray off.

Using cheapness is fine, but when you sell the boat, dont expect to get any medals for having used cheap paints on it.........

Just my 2 cents, whatever that is worth.

Again, if they really covered bare fiberglass like that, I wouldnt go back to them unless you inspected every step to insure a proper job (and it really is easy to do, I would gladly tell you the process I have refined in our shop that the Interlux rep has commended us on several times)
If they just painted over your Gelcoat, (the white) then the job is fine, and continue spot PAINTing until you can afford a decent thorough job.

Again, just my opinion.

Mac

[skip1930]

Unless your a hot shoe racer, like Brackish says why not just keep piling on the layers, it's just going to abrade off anyway.
Mil thickness is usually everything in longevity. Is adhesion important with abrading paint? If not I don't get it.

skip.

[brackish]

IF it was done over bare fiberglass then your yard is a bunch of morons.

Jason, with all due respect I disagree.  If you contracted to have a BARRIER COAT done and then an ANTI FOULING BOTTOM PAINT JOB, and the yard did not do the first but charged you then they are not morons they are dishonest.  If you contracted to just do an anti fouling bottom job, the application guide for Pettit Unepoxy calls for cleaning, dewaxing and sanding prior to application of the bottom paint with no PRIMER required.  There is a significant difference in the cost of the two and the barrier coat will do nothing for adhesion of the bottom paint that the proper preparation of the fiberglass as indicated in Pettit's application guide will do.  It is strictly to reduce the possibility of osmotic blistering.  The two (blistering and marine growth) are separate hazards and their prevention is contracted for separately.

If you are starting from scratch, and your boat is to be in the water year round, particularly fresh water, I would certainly contract to have both done.  But the OP is asking what to do now.  If he did not contract specifically for a barrier coat, he has no beef with the yard.   The barrier coat is not a primer, it is a high build epoxy based coating designed specifically to keep water from contacting the GRP surface.  Certainly they should have made the customer aware of the existence of a barrier coat, and maybe they did, but it is not required for the successful application of the anti fouling coating.

I owned two GRP boats that never had a primer or barrier coat, just ablative anti fouling coatings.  The first a 1966 Columbia Challenger never got blisters when we sold it in 1980.  The second, a 1977 Columbia 8.7 got a few dozen small minor blisters during the 16 years we owned the boat.  It was not a catastrophe.  I think it may still have them maybe with a few more.  And if you ever really want to get rid of them, you drain, dry, epoxy fill and fair them out and move on.  Newer boats are even less likely to get them due to the improvement in resins used.

Just my opinion based on about 45 years of messing with GRP boats, and a recent look at the Pettit application guide for Unepoxy.

[MacGyver]

Brack,
My issue is with the Bare fiberglass, which may not be a issue if there is gelcoat on it.

At our shop we find bare glass, we coat it with the 2000 to keep it from gathering water. If there is gelcoat then it is fine.
The analogy we use is like priming metal, you dont just paint metal, unless it has a primer like ability to keep it from rusting first (or in the case of rustoleum, built in...)

I wish I could agree on advanced resins...... just had a 36 pulled out in the spring for a few gashes from sideswiping a silo in the lake during high water.
He didnt want them fixed, so we put it back in advising him that it could blister...... when pulled 4 months later, blister city.

This could go on all day, and I have heard that fresh water is worse for blisters than that of salt, but I digress..... the exposed glass was a problem, and the poster says bare fiberglass.

IF the boat yard informed him of all of his options, good on them. And maybe it is the pride factor of no return jobs at our marina and our commitment to keeping people informed that makes me critical of others. I wasnt there at the time, nor do I know word for word what was happening as it happened...............I will now keep my nose out of it. 

Mac

[Bob23]

   Sounds like the confusion here is what is meant by "bare fiberglass". Mac is calling that fiberglass without a gelcoat while Brack may be using the term to mean fiberglass with no paint or coating on it. Am I right about this?
   CaptJohn: Both of these guys know what they're talking about and I'd be proud to have either do a bottom job on my 23. Get the hint? Bottom line is that the gelcoats job is to protect the fiberglass. If that's compromised, the barrier coat is the next logical step before any anti fouling paint is applied.
   A bottom paint aside: As I previously mentioned, I used to use Pettit Hydrocoat on my 23. She's in salt water about 6 to 7 months of the year. I got 3 seasons of protection out of the first coat of paint, which was applied over existing hard bottom paint. Next year, feeling guilty about trying to squeeze a 4th season, I applied a second coat of Hydrcoat. Upon hauling, I had growth like I hadn't seen in years. I do believe that Pettit changed the Hydrocoat formula. Now it's Interlux Aqua. We'll see....
   Again, John: Where do you sail?
Bob23
   

[brackish]

   Sounds like the confusion here is what is meant by "bare fiberglass". Mac is calling that fiberglass without a gelcoat while Brack may be using the term to mean fiberglass with no paint or coating on it. Am I right about this?

Yes you are, at least from my perspective.  I made the assumption that when he said "stripped", he meant the layers of paint had been stripped off, and when he said "sanded" he meant the existing gelcoat was sanded as preparation for coating, but not removed.  I agree with Mac if the gelcoat was ground off to the first glass layer.  In that case, I would not even go back with polyester for the final coat over the glass, but use epoxy for all repairs and final top coat.  Then the issue of osmotic blistering is essentially eliminated.

Additionally, if my assumption was correct and the gel coat was still there I would have expected the yard to make me aware of the benefits of a barrier coat and I personally would have gone with it. But as to what the OP should do now, I still think he should just repair the coating, watch for blisters at seasons end haulout, and think about a barrier coat if and when he decides to strip and start over with his antifouling paint.

With regard to polyester improvements, supposedly the switch to vinylester materials was a big improvement in blister prevention, however, I've not seen any statistical data to back up that claim.  And epoxy is still the best material, however it is much more expensive so not widely used in production boat building.