Help! How much trouble am I in? (Bottom gelcoats & fiberglass questions)

Bilbo · Mar 30, 2009

alexnder said:
No good deed goes unpunished. I have a 1979 22 Catalina I've owned for the last 7 years that has been up on the trailer since last year. This spring, I decided to give baby a new coat of bottom paint since it was looking about that time. I began by stripping off the paint and began to see that I fear are widespread blisters in the gelcoat.

The blue is the bottom paint and the white is what I believe to be the gelcoat. You can take a knife and flake off one of these and see fiberglass strands underneath. I don't think sanding it down and putting on the bottom paint back on feels quite right. I'm not sure a gelcoat touch up repair is gonna do it either since there is so many little cracks. I'm not sure but from what little I've read online, if I put this in the water without doing it right, the glass could de-laminate and then I'm in bigger trouble.

I'm fearing the worst at this point. I don't have money for a professional but I do have a do it yourself attitude and a tool or two. I've worked a bit with fiberglass on a kayak project but, I'm not sure what I'm looking at to make sure this is done right or how big of a problem I have.

Any suggestions would be greatly appreciated.

Thanks friends!

From what you've written, it may be an issue. I am not sure if your boat could easily sink though because the fiberglass is really pretty thick down there. (At least 1/4").

I was lucky enough to have found a used boat here with a epoxy barrier coat under the waterline. This has pretty much prevented the blisters in the vinyl resin down on the hull but my boat doesn't sit on the intended waterline ((Low in the stern) and as a result the stern transom had some small blisters. What I did was to take some west system epoxy and coat that area after sanding it a bit. The epoxy is much more waterproof and those blisters don't seem to be coming back after a few years. This gel coat can be so prone to blisters that my boat had some bumps underneath where the 2 plastic "For Sale" signs were taped to the hull.

Bilbo · Mar 30, 2009

From what I've read, sandblasting is too easy to cut too deep. This can also happen with powered sanding equipment very quickly.
One can't tell from the photo what the white layer is.
From the two blister holes in the photo on the mid-far right, It appears as if there could be 1)Antifouling-paint 2)Barrier coat or gelcoat 3)blue Gelcoat. 4)White gelcoat or fiberglass-resin. If the #4 deeper layer is fiberglass-resin it should be fixed.

Generally these boats are with a white gelcoat outer layer but the bootstripe may be of a different color. The hulls are molded in a way that the gelcoat is sprayed onto the mold first, and then the fiberglass after. So, you may actually find a layer of white gelcoat and then underneath a layer of blue gelcoat and then maybe more white gelcoat outside of the fiberglass. Because they are "Production" boats however one can't always expect the highest quality of fiberglass mat wetting and so they compensate for this by making the hull thicker. The more modern method would be to vacuum-bag the fiberglass hull as it's drying where the air is removed with a vacuum system. This is so that all of the matting/chop is throuroughly wetted with resin and the final weight of the hull can be thinner with adequate strength.

The real issue with the gelcoat is that it's not totally waterproof and (Can't very well tell from your photo) what the layers are.
I'd still be tempted to sand it well and give it a layer of Epoxy. Interlux 3000 3001 or 2000E barrier and then reapply antifouling paint if you leave it in the water. Esp salt water

Also, watch that blue anti-fouling paint. It's full of copper poison.

Sylvan · Mar 31, 2009

Blisters

Alexander: My 1974 C22 had quite a few blisters, mostly small but one area flaked off maybe 1 by 3 inches. Scraped with remover and sanded off old bottom coats, then poked out blisters with a knife point, then filled with a good epoxy, then faired, then applied about 7 coats of Interlux 2000E, then sanded lightly with a 600 sandpaper. I keep it on a trailer in winter, in a clear freshwater lake for about 4 months in summer, and the treatment has held up very well, mery much the effort it took. RK

Bilbo · Apr 1, 2009

alexnder said:
Thanks for the reply. From what you're saying and what I've researched, that white layer is probably the gelcoat and I'm not going sailing anytime soon.

I did clean off a section with acetone that went through the white. Under the blue anti-fouling is a thin white layer followed by a thin earthen clay colored layer, followed by a thicker amber clear layer followed by the chopped glass layer. If indeed that is the gelcoat, it is in bad shape the length of the boat but only about a foot or two out from the keel. The sides show no cracking in the white or blistering of any kind. There isn't any foul odor under the chips and there just aren't any bubbles anywhere I can see. I don't know if I'm looking at boat pox or marine growth damage from long ago. Doesn't matter much as it's all got to be fixed.

Anyway I look at it, there's a lot of work to do. I was told that there is a top notch fiberglass shop not too far away from where I live. I'm going to call and see if they'll look at her and (hopefully) give me an idea of what I can safely do on my own. Trouble is, I don't have thousands of dollars to sink into this old girl.

I'll update the post with what the glass guy says if he'll see me. Wish me luck.

Hi,
I know where you're coming from with the cost vs work and wish you the best on this. As Dick and I have suggested, there should be a way to take care of this without spending too much money. Hiring the fiberglass shop may be the most expensive as you know but they may be able to advise you. If you are capable of doing this, I don't see any reason why it should cost more than ~ 300 if you already have a way to raise the boat. -and part of that cost (the antifouling paint) would be a regular maintenance part of owning the boat.

http://www.youtube.com/watch?v=fM-R2_Awgeg
If you do any sanding of the hull yourself don't forget to protect your lungs. Don't skimp on that.

saildork · Apr 1, 2009

Alex,

Fear not! You have some work ahead of you, but it's not as bad as you might think.

I had multiple blisters on my C22, many more than you, but almost all of them were similar to yours. Good idea to have the fiberglass guys look at your boat, but don't pay them to do the work. It will cost you more than the value of the boat. They should be able to give you insights on how to attack the problem. In addition, you should contact the guys at West Systems. Check out their website, call them on their 800 number. They are very helpful. I'm sure the guys at Interlux and the other companies who offer bottom treatment/fiberglass repair materials would be helpful, too.

In my case, I sanded the hull down to the gelcoat. I drilled out (very shallow) the larger of the blisters (I had 10 - 15 of these), filled them with thickened epoxy, faired them, then put seven layers of epoxy barrier coat on the bottom. Follow the directions of the manufacturer before you add bottom paint (I didn't follow them closely enough and now I have flaking bottom paint

). Anyway, you'll end up with a smooth bottom and your boat will be virtually impervious to moisture. And you'll be able to do it for probably < $300 as suggested above.

Go over to Sailnet and search the threads on blisters, bottom paint, etc. and you'll find a whole lot more on this subject. Good luck and keep us posted.

Fair winds,

Pat
C22 Stargazer

Sylvan · Apr 1, 2009

More on Blisters

Alexander: Mostly I applied the 2000 E with a fine foam roller that I got from a maror hardware-- its normally used for polyurethane on wood doors and its cells are small so it leaves an even surface. Used a fine brush for tight places. For the keel trunk, once when I used to use a bottom paint, I applied it with foam attached to a wire that I also found at our hardware outfit. And what I didn't say earlier is that it was about 6 years ago that I did the 2000 E application and it has held up well without any overpaint. RK

Ken · Apr 2, 2009

some work

Alex,
A couple of years ago I faced a very similar project, but rather than blister I had a lightning strike

It took me the better part of a month just to grind out the bad areas left by the strike. Nothing more than you will have to do.

All the loose material will have to go. You can use a dremel, or suitable grinding method. I use a slower electric drill and a 1/4 burr bit off my die grinder. This way I felt I had more control over removing material. Once all the loose material is ground away to solid glass, you start the filling and fairing.

I used West System epoxy and 407 low density filler. (if you save all those plastic credit card mailings you'll have lots of spreaders) If you have the place I would highly recommend you consider turning the boat over, it will cut your job/time by half. Much better having gravity working for you than against. Should you be interested in the method let me know, I will send you the link to the process. I did mind from the bottom, trust me you will get tired of looking up at it. Once at this point it's a matter of fill then sand. You will not want to try and fill them completely in one fill, it just won't work.:naughty:

One other thing you will want to do is get it off the trailer, if you do this from the bottom you will want to watch for oil canning on the front of the hull. I used 55 gallon drums for the rear and ended up making adjustable pad supports for the front. (get yourself a high lift jack makes life much easier)

Everyone is correct on the price, you can expect it to cost you somewhere around 300 - 400 depending on the rise in price of materials. how much you need if you use a barrier coat and what bottom paint you use.
I went back with 2000E Interlux barrier coat and used VC 17 bottom paint.

One other point (tip if you will) if there is a fleet close to you ask them if anyone has done any bottom repairs. It's most likely they have and can help and guide you this project.

Ken · Apr 6, 2009

Alex,
Here is a couple pictures of how we took and continue to take our boats off the trailer.

We use two 55gal drums a 2X8 and a old boogie board for the transom

The bow is supported using a 4X6X14 and concrete blocks stacked two side by side rotated each time until the height is gained so the trailer can be rolled forward.

You can use the trailer jack to lift the boat by letting it all the way down, place the barrels under the transom. Then by raising the trailer the transom lifts off the trailer, place the beam under the bow. You may have to repeat a couple of times to gain the height you need doing it this way. (This is where the high lift jack comes in handy).

The main thing is don't get in a hurry and make sure your working safe.

I included the sled photo, Now is also a great time to finish and fair your keel

saildork · Apr 12, 2009

Alex,

Trust yourself, putting this old gal back into shape is the right thing to do. Let those other guys throw away their own boats.

Just remember, if you use an epoxy barrier coat like West Systems which leaves an amine blush when it cures, wash it well with a scotchbrite pad and soapy water BEFORE you sand it for the application of antifouling paint. Don't ask me how I know this.

Pat

Help! How much trouble am I in? (Bottom gelcoats & fiberglass questions)

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