semi-dry spots in the lamination

So I glassed my first board using polyester resin and to make matters more difficult, the bottom is painted black. It seems as though I might have pulled too hard when wrapping the rails and as a result there are some spots on the bottom where you can obviously see the weave of the 6 oz cloth. The cloth is by no means dry but there is definitely not as much resin between the cloth and the foam as in the rest of the bottom.

Question number one: Is this going to be a structural issue? Is the cloth/foam adhesion critically affected in these areas?

Question number two: Will this be fixed when I hotcoat? Will the sanding resin penetrate and fill these areas to provide some cosmetic relief?

Question number three: If the hotcoat won’t do that then how can these dry spots be fixed? (Please don’t tell me i have to sand through them.)

Thanks to Scott at Foam Fins and Fiberglass for the materials and for his patience.

the real question is how do you want it to look, sure you could just finish it and it will probably have a good life and look like crap, if you really want to fix it you have to expose the dry spots (sand them, sorry!) if they are really bad i would open them up and do a little suncure coat on the spots where needed before i hot coated, the hotcoat will NOT fill these without good prep work, are these spots in the deck or bottom lam? also you could have used to much paint in spots (which will cause crystalizing and black paint is notorious for this), did the lam look good before it cured? do these dry spots sparkle in the sunlight? look on the bright side the next board you do you will be mindful of your paint use and make sure your laps are saturated and pulled tight, i always kneel down and make sure my laps are pretty as the last step of lamming, you can always clean up with a brush inthe end if you need too, i hope this helps


It might be too late now, but next time try to have a look at what it looks like just after the resin has gelled. At this stage you can still do a filler coat with laminating resin (you may make it a bit more fluid by adding some styrene) and it should fix those silvery looking pieces of glass.

thanks to the both of you for the replies,

the problem areas are on the bottom. I think that as I was glassing initially i could tell that some small areas were more dry when viewing the surface at an angle. But only after leaving it overnight did I fully see the problems. If I was to start sanding to fix these areas, I would most likely not be left with much glass. These areas would need to be patched, right?

As for the black paint, I used black latex paint out of a rattle can but applied it in thin coats over about 4 days specifically to ensure against crystallization. Ive never seen crystallization before but it looks like I’ve got it on the board. What exactly is happening in that process?

could have been resin drainage witch is a result of to little catylist and the resin(liquid)drains out of the lam onto the floor