The side fin off this board broke off. I had repaired it before when it had a crack at the base of the fin that ran from the fin to the rail.
After the fin completely broke off again I could see that the reason why the fin cracked was that the foam underneath was broken all the way through so that part of the tail foam is barely connected.
The cracked foam runs about 4in to the left of my thumb.
Any ideas how I can repair this so that the fin doesnt break again?
Grind off any damaged,delaminated, or soft glass all around the broken out area. Gently (real gently) prop open the split in the foam and get some catalyzed lam resin in the gap. Overfill it, wipe off the excess, and run some tape over the rail to hold it until cured. Prep sand the surrounding glass about 1". Level the area for repair on the stands. Tape around the missing glass, and run a wide piece of tape along the rail about 1/2" higher than the bottom (bottom facing up). Mix a batch of sanding resin and Q-cell fairly thick; pigment it to match the board color. Pour the mixture into the exposed foam and spread it around evenly. Let it run over the rail against the wide tape. When semi-hard, surform to the rough shape. When fully hard, sand and bring everything back to the orignal contours and levels. Repeat the filling process if needed. Tape off and laminate 6 oz. cloth 1" outside the filled areas. Lap it over the rail to the deck for more strength. Hotcoat, sand. Clean up the old fin or get a new one and install it. Glosscoat,final sand, polish if you want to. You don’t have to finish this in one day, so take your time and do a good job.
Howzit J, What I do to repair those fractures is take a bamboo Skewer, the thin ones and use the tip to widen the crack then use the other end to widen even more. Next make a batch of thin Q-cel and lam resin and slowly fill the crack, like I said do fill it slowly to make sure the area gets totally filled. after this you might need to use more Q-cel and resin to fill any other holes or damage that was done ,then just glass over the area and attach the fin like normal. That fractured foam is the reason a lot of fin repairs fail, it’s like building a house on top of a earth quake fault. Also a lot of boards that get buckled or really streesed can have the same fracture but it’s a lot harder to find and so a repair on one has a tendency to fail if just glassed over. Aloha,Kokua
Thanks guys! I know I was totally stumped why the fin broke off the second time till I saw the foam was broken. Ill fix it like you guys suggested, thanks again!!