fiberglass repair

I have a lot gelcoat spider cracks you know the little small ones and as I restore this boat I am looking to do something. They are mostly on the back quarter of both sides by the grills. I have a 260 merc cruiser. Thoughts on repair?

[Stinky_Hooker]

Paul..I have done alot of fibergalss work over the years and in that situation it seams that in the past this has worked best for me.....I usually ...if it is not a spidercrack due to weakness, just age and cosmetics:

1.sand the gelcoat down a bit just to get the gloss off, or just a hair further...remember the more surface you take down the less depth left to fill the cracks

2.then i use spot putty also called glazing putty, you can get this at any auto parts store that carries body working products like bondo, it is usually a redish color and it is ready to apply straight out of the tube, just put it on by hand or with a putty knife if u prefer

3. after drying lightly sand again...by hand and wet sanding is best as this is not super hard stuff

4.spray over with several coats of primer...wet sanding between coats....very light coats , this will fill in any imperfections that are left....note if you think the cracks are still prevalent after the putty and before the primer then go with another section of putty...sometimes it takes several if the cracks are deep.

PS if the cracks are really deep, say more than a 1/16th of an inch then bondo or short strand fiberglass may be required before the spot putty.


This is just my 2 cents as i have restored quite a few boats with similiar problems