This summer i had a lot of fun (too much, perhaps) kitesurfing with my FST dominator. After a few sessions i noticed the deck becoming soft and i decided to remove the wax to see the extent of the damage. To my surprise the board had a buckled deck, the outer fiberglass layer was broken and water had gotten inside the board (panic!)

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I decided to repair it myself and take some photos along the way to share here with anyone else having the same problem. For more information about repairing epoxy sandwich boards like firewires go to Eva Hollmann's fantastic webpage http://www.boardlady.com/

First step in repairing a soft deck should be to make some holes around the damaged area and inject poliurethane foam under the sandwich layer to fill the voids between the pvc and the polystyrene core. In this case, driven by panic and seeing water coming out of the cracks in the fiberglass, i decided to sand the whole thing down to expose the polystyrene core and let it dry for a couple of weeks:

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Only after the board was completely dry did i inject polyurethane foam inside the polystyrene. The best thing would be to use a two component PU liquid system, but that's not easy to find so i used common PU foam spray:

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Then i started digging the polystyrene to remove any part made soft by the salt water and glue in new bits of polystyrene (again using the PU foam):

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After that comes the more complicated part. To recover the board's integrity we need to redo the pvc sandwich layer, so the whole are needs to be carefully sanded and a new layer of 3mm PVC foam (divinycell or corecell) needs to be glued with epoxy resin and a layer of 4oz fiberglass to the beveled hole. The gluing has to be done under a lot of pressure to remove any air and excess resin between the layers. In the case of small holes this can be done using weights to press down on the pvc, but ideally one should do it using a vacuum pump and a vacuum bag:

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In this case I used an old vacuum pump, some pvc tubing and some polypropylene film i had left after covering my kids schoolbooks. Before gluing the bag with vacuum tape it's also good to cover the area with waxed paper (or peel ply) and a breather cloth (or in my case mosquito net) to allow the air to flow inside the bag. I got everything ready, mixed the epoxy resin, sealed the bag and left the pump pulling vacuum for around 5 hours (until the resin was set):

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