Survey!!!
Just a few pics on the day of the survey
Arrghhh!! The Pox! This is what it's all about - the dreaded osmosis. The surveyor just said "Wooden boats rot, Steel boats rust and GRP boats get osmosis". This is where water gets past the outer gel coat and into small voids in the chopped strand mat underneath. Here, it reacts with the resins in the layup to produce styrene whose molecules are too big to get back out of the gel coat again so it produces a blister (this was how it was explained to me anyway). If you pop one of these you get a smell of vinegar. This is an enlarged picture of the bow just below the boot line and shows the blisters quite clearly. Treatment consists of removing all the gelcoat below the waterline then opening up all the voids in the layup using a light grit blast followed with at least two weeks of washing each day with a pressure washer to remove as much of the styrene as possible. Once done the hull then needs to dry out. This is checked by using a moisture meter each week. Once the numbers have come down sufficiently to indicate that the laminate has dried, the boat is moved into a covered hangar where heat lamps are used to dry the final moisture out of the hull. When all this is done, the hull is given a specified number of coats of epoxy and then finished off with anti-foul.