Gelcoat Repair Reference(s)

[markpj23]

Lots of choices out there for instruction books on gelcoat repair. I have some stress cracks and the like topsides that I want to address.

Any "must have" reference books / manuals you can recommend? My experience / skill level is 'novice' in this category...

[Terra Nova]

Originally Posted by markpj23

Lots of choices out there for instruction books on gelcoat repair. I have some stress cracks and the like topsides that I want to address.

Yo Mark,

when repairing stress cracks it is important to grind away all the gelcoat down to the fiberglass, and apply mat/resin prior to re-gelcoating, or the cracks will reappear. Leave the matted area a little low to allow for the thickness of the new gelcoat.

best, andy

[delmarrey]

Originally Posted by Terra Nova

Yo Mark,

when repairing stress cracks it is important to grind away all the gelcoat down to the fiberglass, and apply mat/resin prior to re-gelcoating, or the cracks will reappear. Leave the matted area a little low to allow for the thickness of the new gelcoat.

best, andy

This all depends on the cause for the stress areas. A lot of the time one needs to reinforce the UNDER SIDE. One example would be the corners of a cockpit area. If the deck is not supported properly the deck flexes causing the cracks. And they just come back if the original problem is not fixed.

Other places include; the outside corners of the cabin. around stantions, around chainplates, winches, cleats, mast tabernackle/base, pedistals and so on.

Good old boat is a good start but here's a couple more:

http://www.greatwhiteboatco.com/

http://www.tracycommunications.com/g...tm/gelcoat.htm

[Terra Nova]

Originally Posted by delmarrey

This all depends on the cause for the stress areas. A lot of the time one needs to reinforce the UNDER SIDE. One example would be the corners of a cockpit area. If the deck is not supported properly the deck flexes causing the cracks. And they just come back if the original problem is not fixed.

Other places include; the outside corners of the cabin. around stantions, around chainplates, winches, cleats, mast tabernackle/base, pedistals and so on.

Yo Del,

good post and a great point to bring up! That the reason for the stress crack is STRESS. Sometimes the design of stanchion bases for example focuses the stress on a very small area. Perhaps the builder failed to provide enough material in that area, and likely failed to provide a sufficient backing plate, well bonded to the deck's underside. So a thorough repair will include more than just the obvious cosmetic issues--it will mean solving shortcomings created by the original builder.

This is such a good example of one of the essential differences between entry-level and bluewater boats--one's ability to withstand expected loads.

best, andy

[DeepFrz]

Mark, because you had trouble where a cleat was pulled from your deck I would suspect that the hardware on your boat was installed with inadequate backing plates. This is one place to check very carefully. You might also want to double check the fiberglass layup in the areas where you have stress cracks to see if it needs reinforcement.

[GordMay]

See also some earlier discussions, especially Jeff’s "Primer..":

“A Primer on Fiberglass Construction”
http://www.cruisersforum.com/forums/...ction-619.html

“Gelcoat Crazing”:
http://www.cruisersforum.com/forums/...t-1-a-944.html

Interior Crazing:
http://www.cruisersforum.com/forums/...azing-948.html

[markpj23]

Originally Posted by DeepFrz

Mark, because you had trouble where a cleat was pulled from your deck I would suspect that the hardware on your boat was installed with inadequate backing plates....

Yeah - I already know that cleat was installed w/o backing plates by the previous owner - not the factory. Checking the others to be certain is high on my list.

The stress cracks I have are on the cabin sides in the corners of some fixed ports / plex windows. Right at the radius curve on the lower section of the port. Cracked in the same spot on both sides. I assume this is due to flex.

Thanks for the replies here folks!