Bottom Paint Removal Project

[balistikb]

History:
Ok so I have a 1999 20ft Cobia CC that I bought 2 years ago. It had bottom paint on it when I bought it and it was time to either reapply or remove. My boat is never kept in the water and always on my trailer. So I decided to start removing the bottom paint with the hopes of putting on Interlux VC Underwater Epoxy. From what I read this is a good product. I was also considering Pettit Vivid White do to some other reviews. I really didn't want to go this route since I don't need the bottom paint features.
Problem:
Ok so the problem is this, I started removing the bottom paint and found what I think are blisters (popped). I am attaching pictures to get opinions on it. What are my options going to be in order to repair this problem? Please keep in mind that I am doing this myself and I really don't have much money to spend on this project.

Before
http://i224.photobucket.com/albums/dd234/balistikb/IMG_4820.jpg

After removal
http://i224.photobucket.com/albums/dd234/balistikb/IMG_4816.jpg

Close Up
http://i224.photobucket.com/albums/dd234/balistikb/IMG_4818.jpg
http://i224.photobucket.com/albums/dd234/balistikb/IMG_4819.jpg

 

[TilliamWe]

Re: Bottom Paint Removal Project

Okay, I am no expert, but I doubt those are blisters. that looks like impact damage. But regardless, you need to make sure that the fiberglass that is exposed is not delaminating. I am not exactly sure how you do that, though, as I am not an expert. You would also want to make sure that the exposed fibeglass is completely dried out, before you cover it with anything.
As far as I know... if the structure of the boat is not weakened, the core material (if any) under that exposed fiberglass is not saturated with water, and you get it completely dry, you can just seal that with an epoxy.
Since you were planning to put an epoxy finish on it anyway, the only choice you have to make is how smooth do you want the area to be? You can get some actual epoxy filler and fill it and sand it smooth and then put your VC stuff on over it like paint.

If I am totally off base on my assumptions, someone on here, far more knowledgeable than I, will let you know.

 

[balistikb]

Re: Bottom Paint Removal Project

Thank you for you opinions. I do want to make the finish as smooth as possible so filling it with something would be best. I welcome any other suggestions.

 

[balistikb]

Re: Bottom Paint Removal Project

Btt

 

[cheesegrits]

Re: Bottom Paint Removal Project

Those are either blisters or delaminations from blisters. you need to grind them out until you get to solid glass, feather the edge back into the the good glass. Then take epoxy resin and wipe area then lay fiberglass mat into wet area, then wet mat out with more epoxy. Do this until the ground out area is slighty higher than rest of hull. Let cure overnight then sand down flush or as close as you can. The mat will reinforce any weak spots and since it is nondirectional it won't show the weave like a cloth will as you sand. After you get it close find some fairing compound and wipe area with it. Sand fairing compound smooth then prime with some kind of epoxy barrier primer. Then paint with the bottom paint of your choice. This Will work on most situations , but depending on how deep you have to grind will determine exact procedure. Good luck and post back as to your decision and if you need more info as this post was definitly the quick version!

 

[erie_guy]

Re: Bottom Paint Removal Project

Those are either blisters or delaminations from blisters. you need to grind them out until you get to solid glass, feather the edge back into the the good glass. Then take epoxy resin and wipe area then lay fiberglass mat into wet area, then wet mat out with more epoxy. Do this until the ground out area is slighty higher than rest of hull. Let cure overnight then sand down flush or as close as you can. The mat will reinforce any weak spots and since it is nondirectional it won't show the weave like a cloth will as you sand. After you get it close find some fairing compound and wipe area with it. Sand fairing compound smooth then prime with some kind of epoxy barrier primer. Then paint with the bottom paint of your choice. This Will work on most situations , but depending on how deep you have to grind will determine exact procedure. Good luck and post back as to your decision and if you need more info as this post was definitly the quick version!

I agree that this is damage from Blistering that was incorrectly "repaired" by painting over the damage. You should correctly repair the damage, then apply a barrier coat of paint, followed by several layers of bottom antifouling paint. I used the Interlux system and have had no complaints for the last several years. I now just touch up the ablative layer of paint each spring.

Your next step is to remove the damaged gel coat layer that has the circular blister remnants and reseal the exposed fiberglass matting. Your damage is identical to my 32' chris craft that had thousands of such dimples (blisters) along the lower spray rails. After using a dremmel to remove several hundred blisters, it was easier to get an "end router" and use a rotozip to peal the gel coat from the spray rails. I believe the marina's use a planer tool to peal off the gel coat layer. Just don't cut too far into the underlying fiberglass- or you will also have to add a cloth layer as described by Cheesegrits.

Once exposed, let the fiberglass dry out for a couple of weeks - then seal the exposed glass fiber with a coating of CPES from RotDoctor.com. Apply the CPES with a paint brush allowing it to soak into the fiber until it refuses to accept more. Allow this to cure, then apply a gel coat layer to the repaired surfaces. You can paint this on with a brush/roller as you wish and then sand (fair) to a smoother finish prior to applying your barrier coat and antifouling paints.

This is a very time consuming task that would cost several thousands of dollars if you choose to have a marina do it for you. It took me a fall and spring season to complete the work, but you have a good start at it with removal of the old paint.

Lots of boating season left this year - so it's time to get with it!

 

[balistikb]

Re: Bottom Paint Removal Project

Thank you everyone for your thoughts.
Why can't I just seal the holes with Marine-Tex and then paint with and Epoxy paint as I stated in the beginning of my post? Not questioning your answers but this my be far too advanced for someone at my level. I would like to try and stay away from bottom paint if I can because my boat only goes in the water when I go fishing?
Could your options be the only one available to me?

Thanks again.

 

[Chris1956]

Re: Bottom Paint Removal Project

I cannot tell from the pictures if they are blisters or not. See if you can sand them out and fill the bad holes (if dry) with marine poly putty. If you detect wetness or uncured resin, you need to remove it (wipe with acetone?), before filling.

I would then coat with epoxy barrier coat (3 coats at least) and sand with 150 grit, and then 220 grit and apply marine polyester paint.

 

[cheesegrits]

Re: Bottom Paint Removal Project

The only reason to use epoxy resin first is to completly saturate the open weave you have exposed. The problem with just using marinetex you might not get it down into the exposed strands enough. The problem with using epoxy resin by itself its not very strong,yes it bonds better than just about anything else ,but embedded into the mat creates extreme strength across the repair.The fix I told you about you won't have to worry about ever! Just more paint when the time comes.

 

[balistikb]

Re: Bottom Paint Removal Project

not exactly what i wanted but still came out good.

 

[bigbad 4cyl x2]

Re: Bottom Paint Removal Project

diddnt look like the blisters i see on sail boats. that looks like a bottom job from a boat yard, looks like vc performance

 

[balistikb]

Re: Bottom Paint Removal Project

I don't now what you mean but I can tell you it was VC Performance epoxy paint.

 

[bigbad 4cyl x2]

Re: Bottom Paint Removal Project

the blisters on sailboats are huge look like lumps. good choice using the vc performance epoxy ,how many coats of the vc did you use ,did you spray it . and are you going to burnish the sides

 

[bigbad 4cyl x2]

Re: Bottom Paint Removal Project

;

; vc performance sprayed on 3 coats , im afraid to burnish it

 

[balistikb]

Re: Bottom Paint Removal Project

they were blisters indeed. I sanded and grinded them down and the picture you see was the result of that.
I had many from small to large that I had to pop and fix.
I put 4 coats and rolled it on. I painted while it was over my trailer so i didn't have the room to spray.
I don't know what barnishing is so I didnt give it any thought.

 

[lmannyr]

Re: Bottom Paint Removal Project

nice work. Looks like new. Why are you not totally happy with it?