OK so I just finished my first EPS/Epoxy fish. After it cured for 7 weeks I got some really decent rides on it, even on the big swell we just had, then last night pulling into a little chest high barrel I felt the tail slide out. Next wave same problem, when I rolled the board over I could see the left fin flop back and forth. The glass had pulled away from the foam as far as I can tell. I sealed the board with fast and final and attached the fins to the board with 2 minute epoxy, fin rope and full fin layups (2 pieces of 6 oz. glass). Is this a common problem with EPS? Also whats the best way to fix it? I was thinking of cutting away the glass, patching, and reattaching the fin, but would like a simpler solution. Would love to get this fixed soon as my old PU/PE thruster feels like paddling through mud now that I’ve gotten used to the fish…
It’s not a common problem with EPS. I’m assuming you only used 2 minute epoxy to set the fins, not to glass them on. The glass came off of the foam, or did the fin come apart from the bottom side glass? If the bottom delammed, you likely have other issues. How much spackle did you use? If you got it on really thin, and screened it prior to glassing, you should be fine. If you left it fairly thick, then that’s a likely culprit. Did the board ever get excessively hot? Just another in an endless set of possiblities as to the core problem.
I wouldnt consider the spackle job light, though its the first time I sealed one so I’m not sure what to compare it too. It didnt look any thicker than Loehr used in Epoxy 101 and I sanded it smooth. The board never got hot. Just flipped the board (It’s still draining so I’m assuming it got all the way to the foam somewhere). Where the resin and fin rope are just at the base from the back of the fin up about halfway is a long crack. The front of the fin looks like its still attached to the glass. It could have been possible the layups just pulled off due to the lack of strength at the base. I’ve done several fins with the same amount of rope though and had no problem over much heavier use. I might be able to reattach it and put more rope and larger base layups to avoid having to cut away down to the foam.
Hey bfrenck,
Did you lam in a tail patch or some football patches for strength?
When glassing on a fin make sure the fin roving goes up the fin about 3/8". Same distance out on the flats...
Also have the layers of glass run all the way up the fin and about 2" out on the flats, both sides.
~Brian
not sure if this is what happened but some fins need to be scuffed or the glass will peel off them
If you used a low density EPS I would say its a sure bet that the beads have seperated under the load of the fin.Check if there are beads on the bottom of the fin.If not then it is a delam problem from either too much spackle or a bad bond between the rovings, glass and fin and the bottom lam. Idont know about RR but when I set fins on with any epoxy I always make sure the bottom lam is scrubbed then sanded to achieved maximum mechanical bond of the fins.
Daren
If it's 1 or 1.5 foam you have to beef up the laminate under the fin area. With 2# this doesn't happen. It's the foam coming apart from itself.