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  • #4258

    i need some help as we discoved last week that our tanks are not watertight, we capsized and everything filled up. i was wondereing if you can get replacement seals and if so where from?? also would anybody recomend the use of bouyancy bags in the tanks as well, if so do you have any ideas where to get them from and their sizes.

    any help would be much appreciated

    debbie simpson


    Sealing the buoyancy tanks can be a tricky task, but you need to do it to get a measurement certificate for class racing.
    There are some good articles online about various methods for tracking down the leaks.
    However as a quick fix I would definately suggest installing some buoyancy bags or whatever inside the tanks. Some people use the plastic bladders from inside boxes of wine, possibly because it is quite enjoyable disposing of the original contents.
    I think the two tanks are supposed to have a certain amount of foam buoyancy installed anyway, by class rules- about 40l per tank IIRC. This is to help prevent the boat from foundering should the tanks flood. However it would not be enough to keep the boat floating high enough to be recoverable.


    I had some difficulty getting an airtight seal on the aft hatch on my GRP Mk II Kez with the rubber in its conventional place glued to the deck.

    With a bit of lateral thinking I have achieved a good seal putting a 9mm thick neoprene foam strip on the inside (underside) of the hatch cover, having made sure that the edge of the lip on the deck was flat (using two lengths of thread on the diagonals and a good straight edge looking at the sides). To flatten the athwartships camber (not often you can use that word!) of the hatch cover I obtained some closed cell polystyrene foam as used by architectural model makers and stuck 4 x 25mm wide strips along each side above where it rests on the deck flange/lip using epoxy with glass micro-balloons to make a gloopy paste in the underside the hatch cover and made a wooden jig to allow me to sand the surface of the foam flat and then sealed it with glass cloth and epoxy with more micro-balloons. The self-adhesive neoprene foam was then glued on with the corners very carefully mitred.

    The result is that the seal is well protected from snagging and ultra-violet. I held 150mm water gauge for about 5 minutes before I got bored sticking my tongue in the tube to maintain the seal. Fortunately there was no one around to photograph me during the test…

    Less success was had at the bows chamber where a “water-tight” hatch by a well known manufacturer failed to seal (smoke streaming past the O-ring) Only copious amounts of grease and serious grunting it tight shut have succeeded in sealing the hatch. I hope I don’t need to open it anytime soon.

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