Blisters in gelcoat

[i386]

I'm assuming I'm using the correct term. I have quite a few areas on the bottom of my hull that are cracked like a spiderweb. Some sanding reveals that the gelcoat has come "unstuck" from the fiberglass in these areas.

I have sanded a few of these off feathering back to where the gelcoat is adhering like it's supposed. In a couple spots I've sanded through the fiberglass. I will repair all of these from the inside with fiberglass cloth (10oz probably) and epoxy resin.

My questions:

Should I continue to sand/grind these out? I don't expect to ever have a showroom finish on this boat but I don't want whatever I end up using to flake off in these areas either.

Once properly repaired from the inside, should I fill the outside with an easy to sand fairing compound or (difficult to sand) resin with milled fibers?

 

[drewpster]

Re: Blisters in gelcoat

I would not use fairing compound as they use fillers that can allow water to penetrate. Since you have elected to use epoxy, I would use a non-blush type resin and milled fibers. Sand it, then use resin and cab-o-sil. sand again, then use primer to bring the surface completely fair. Then paint the whole hull. It takes a little more elbow grease but water intrusion will never be a problem and you get the adhesion benefits of epoxy

 

[i386]

Re: Blisters in gelcoat

That makes sense. Thanks.

 

[flashback]

Re: Blisters in gelcoat

what you are describing dosn't sound like any blisters I have seen.. sounds more like stress cracks. What kind of boat is it? you really had to work at it if you sanded all the way thru!!

 

[i386]

Re: Blisters in gelcoat

There's a bunch of pics of my boat. Just click the link in my sig. Near end of the photos you can see where I've circled them with a red sharpie. Click the picture and then the magnifying glass icon and you get a pretty close up view. I think I need a little finer grit on my sanding disc is why i went all the way through. That and some practice should help.

 

[drewpster]

Re: Blisters in gelcoat

Looks like you have your work cut out for you. Considering the boat's condition I would spend considerable time thoroughly inspecting the entire hull for damage and soft spots. There is no question in my mind that it can be saved, but I would take my time and do it right. The best thing about doing a project from the ground up, as in your case, is that you can rebuild her in better than new condition. (just like steve austin)
keep us posted!