Paint over crazing

[tuantom]

I just finished sanding the the entire gel coat off the transom of my 1967 24' cuddy cabin boat. It is a slooooooow process. The gelcoat has crazing just about everywhere - and it seems to go all the way to, and stops at, the fiberglass. Do I have to sand the gelcoat off entirely when preparing for paint?

I am planning on using Perfection paint (above the water line), but, according to the tech @ Interlux, the epoxy primer it requires is not of the high fill variety. I was planning on sanding the gelcoat smooth w/ 100 grit, and then use as many coats as necessary of high fill primer to fill in what remains of the crazing - sanding w/ 220 between coats.

To clarify: right now, the crazing can be felt with a fingernail. When I say smooth, I mean so it feels smooth with my fingernail.

Could I first use a automotive type high fill primer to smooth the surface, then epoxy primer before paint? Or could I use a glazing compound over the entire surface of the hull to fill in the crazing and the million pin-holes being uncovered?

[ondarvr]

You don't normally need to remove the gel coat for painting, in fact it's better if you don't, but in your case if the gel coat is that bad (crazing), then you should.

If you can still feel the crazing, then it will show up in the paint or come back in a short period of time, even if filled and covered completely.

[mike steiger]

Hi,
If you have removed all of the gell coat you should use an epoxy fairing compound, then two or three coats of an epoxy high build primer and then finish with a two part urethane. I like Bluewater Marine brand they received a very high rating from power boat reports for quality. All of the products are available at very reasonable prices at www.nationalpoolfinishes.com.

[mike steiger]

Hi,
Forgot to tell you all of these products can be brushed if you do not have spray equipment,and unless you have a fresh air supply system you really should not be spraying this stuff anyway. Just follow all of the directions and measure the amounts precisely and you will get good results.

[mike steiger]

Hi again,
One other thing, Ondarv is right it may show up again,if you have removed all of the gell coat already you can put a layer of stitch mat on the transom and then maybee a layer of 1708 and another layer of mat before you fair,prime and paint. Once this is done I doubt you will have this problem again. The 1708 is structural and the mat will even things out a bit.

[tuantom]

I've removed about 50% of the top-side gel coat now - slow and laborious - but it's moving along. It's uncovered lots of pin-holes; but I suppose that is expected. After the boat is sanded w/ 100 grit, I am going to fill the holes, large and small, with microballoons and a little cabosil mixed into epoxy. Then go over it again w/ 150 grit before priming. Does this sound right?

The bottom is going to be a bear to deal with - I'll be ready for my Blue Man Group audition by the end of it.
Is 60 grit too aggressive? I plan on sanding the gel coat down a bit (after I get through all the paint) and doing a little fairing in a couple of spots while I'm down there.

[tuantom]

I've never heard of Blue Water before; but I like the price. How does their two part hold up against Perfection?

[mike steiger]

Hi,
Really no difference, just as good and about 30 percent less. I found out about it through power boat reports, they are the only puplication that does not advertise and is totally unbiased as the receive no money from manufactures. They gave four stars. Their fairing compounds and epoxy primers are very high build and do a great job .

[mike steiger]

Hi,
Forget the micro ballon mixtures that stuff flys all over the place, been there and done that. Go with the bluewater fairing compound it comes in a four gallon unit. The other fairing compound I think is great is System 3 quickfair. You can't miss with either one of these products. System three is mixed by weight 3-1 ratio, Bluewater is by vloume 1-1.