Spider cracks

[Brad18489]

Hi: I have a freshwater Beneteau 400 with a maze of fine spider (stress)cracks all over the hull below the waterline. some appear to be caused by incorrect cradle placement/adjustment and trucking but others seem to be completely random. I am unsure how concerned I should be about this state of affairs. I have been told that it is strictly cosmetic and is not an issue unless it leads to blistering (which has yet to occur). Beneteau of course, pleads ignorant however others have told me the gelcoat was laid too thick and cracked as the hull flexed.I would welcome your thoughts on this situation and if a repair is needed, directions to detailed instructions. I have included a pic of some of the most severe areas.

 

[Travis]

Easy fix, just need time...

Use a small dremel and open up the cracks in the gel down to the glass. Try to obtain a width of about an 1/8th of an inch. Once you have them opened up, let them dry out for a few weeks if you notice any water, if no water present, clean the area with Interlux 202. Fill the cracks with Interlux Watertight, and sand smooth. Cover the area with barrier coat and bottom paint as per manufacture's specs.

 

[TT]

Keep the laminate dry

Brad - I don't want to join the ranks of self-appointed "experts" but as a fairly recent owner of a 25 year old f'glass boat, I've done a lot of researching on the subject and the consensus indicates that you want to keep water out of the hull laminate at all costs.The integrity of the gelcoat + bottom paint is how this is effected; once water gets into the underlying polyester laminate, nasty things can happen, though this may take some time.If you've got extensive "stress cracking" below the waterline, I recommend getting the opinion of a fully qualified expert to assess the reasons for the cracking. There may be "hard points" or other structural problems that should be addressed to prevent recurrence of the cracking. If the cracking is confined to the gelcoat, the repair is fairly simple, though tedious. If the cracking extends into the laminate, then structural repairs may be required before the gelcoat is restored. Either way, you may want to consider application of an epoxy barrier coat (actually 4-5 coats) after all the repairs are done. ALL this work involves the use of rather specialized ( and expensive ) products and the manufacturers recommendations should be read twice & followed carefully to ensure success. There's lots of info available about "how to"; getting the objective opinion of a "fully qualitied expert" may be the biggest challenge.

 

[Bruce Niederer]

gelcoat cracks

Both the previous responses are perfectly valid. You should carefully inspect the hull with the issues TT brought up in mind before deciding whether to make the easy repair or if the more involved repair is necessary.

 

[ron]

had similar problem

I had stress cracks in the keel, bow and rudder areas. Fought with beneteau for 2 yrs.They said it was cosmetic i disgreed. I hired a surveyor and told them I was going to have the hull shot with a thermal imaging camera. Finaly they agreed to fix it. The problem was the scrim layer was not wetted out properly and under that in the laminate there was some cracks. Beneteau ended up doing a complete bottom job.