This stuff any good for hull crack repair??

[drewmitch44]

Ive got a couple of small hull cracks that look to have been there a long time. I think i would like to use this stuff to seal up the cracks before i start preping it to paint it this winter. These are smallcracks that im talking about and dont seem to be verry deep. I use the boat every weekend and i know it leaks a little somewhere but its not verry much. I just want to fix the little cracks before i paint the whole hull this winter. I tested it on a small area and this stuff cures hard as a rock. Any opinions on it?????

 

[erikgreen]

Re: This stuff any good for hull crack repair??

I haven't tried the star brite, but I've used several other epoxy putties. They are generally about as good as any epoxy with filler is for patching small holes, except they may be harder to work and to sand.

Half the reason people use Marine-Tex so much is that it can be smoothed like frosting and sands fairly easily.

A putty like this may have metal fillers (some do, like JB weld) and may require grinding, not sanding. If it has iron fillers, it also may be vulnerable to rust, or with other fillers you may get the dissimilar metals problem causing electrolytic corrosion.

In short, if you repair a small ding and cover it you're probably ok, but for larger repairs epoxy with chopped fiberglass as a filler and cloth or roving to strengthen and cover the repair is a better choice.

Also, if the repair must be structural, don't forget to grind back from the repair a minimum of 5x the thickness, 12x if possible in a radius to get plenty of space for your epoxy/cloth to adhere to.

Erik

 

[Mark42]

Re: This stuff any good for hull crack repair??

I agree. stay with a marine epoxy like Marine Tex. I am assuming you are talking about simple stress cracks in the gel coat finish. They generally are only 1/32 to 1/16" deep (ie through the gel coat, but not the glass layers below). If that is the case, you might want to think about widening up the cracks with a grinder or hand held scraper to make a V shape that can be filled with epoxy or even poly resin with a thickener like Cabosil. Then sand and paint. If the cracks are not enlarged and have fresh material showing, the chances of the cracks coming back are much greater than if they are scrapped before filling.

Some folks call them Spider cracks because they often look like a spider web. I have some on my MFG on the front deck. I decided it was not worth the effort to re-gel coat to get rid of them. I chose to just polish the existing gel, cracks and all. An application of colored wax (available at most big auto parts stores) generally hides it. From 5 feet away you can't hardly tell. So if you are going to paint to hide the cracks, consider polishing and waxing. If the gel is past the polishing point, go for filling and painting.