Latest News: Forums Technical Mk 1GRP rear hatch gasket

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  • #28854

    Hello all

    Having just smoke tested my rear buoyancy compartment, it’s clear that I need a new hatch gasket! The current one is rubber/neoprene and is glued to the hatch. The only new ones I can find online are at trident. These are self adhesive foam which the info says are applied to the hull. I had thought the gaskets go on the hatch; does anyone know which is the best option and which material is best?

    Really appreciate the advice


    Bob Harland

    There is a bit of advice on this subject at WIT;

    Quite a few people selling hatch seals for boats, try and source something close to the dimensions of the existing seal/gasket. As long as there is some compression on the seal, fitting it to the hatch is fine.
    I have seen sponge seals and more solid rubber seals used. It depends on how flat your surfaces are, solid rubber will give a better seal as long as there is good contact all round – ie surfaces are flat. Otherwise a sponge material will deform more and tolerate less level surfaces.
    Check by removing the existing seal and see how close the mating surfaces are and if there are any gaps.

    Hope that helps




    Thanks, that’s really helpful. Out of interest is it normal.for the seals to be on the hull or the hatch?  The boat had the seals on the hatch when we bought it, and there is no residue on the hull to indicate previous seals there, but would be interested to know what the norm.



    Tim Jeanneret

    I’ve only ever seen gaskets on the hatch, not the deck/bulkhead. I can’t see it matters once the hatch is in place, but advantages of sticking the gasket on the hatch include: 1) marginally easier to apply the gasket exactly where it’s needed on the mating surface; 2) deck/bulkhead is “cleaner” when the hatch is removed – less likely to snag/tear the gasket if you’re loading kit into the compartment or sitting on the aft deck.

    Dave Barker

    I’ve had good results with the ‘Plain Expanded Neoprene’ (non adhesive-backed) strip from plus some 2-part contact cement. The seal strip material could be described as a fairly stiff dense foam.

    Regarding location, our previous boat (Mk2) had the kind of rear hatch cover with narrow downward-facing edges – like a biscuit tin lid – so the seals were mounted around the opening in the aft tank rather than under the ‘lid’.

    Our current boat (Mk1) has a plywood hatch cover, making the contact area ‘flat against flat’, so the seal is mounted to the under-side of the lid.


    I used PEN22 neoprene and A262 waterproof glue from Seals Direct who though expensive are very helpful and will send samples which are useful. I used it very successfully on front and rear hatch on my elderly  Mark 1

    Only word of warning is that you need to plan application like a military operation. Once the glue touches IT IS STUCK. Not difficult if you do dry runs preferably with a calm helper before sticking in anger and agree on a procedure. But if you let the seal contact even lightly before you are ready…….

    Hope I haven’t put you off it’s not too bad if you take due care. Good Luck




    I should have said that my Mark 1 is fibreglass but i’m sure that the same will work with a wooden one. My advice is ring for a sample you should get it next day


    I also have to replace the seal for the rear hatch of my plus s (incidentally the seal is stuck to the hull rather than hatch).

    Can anyone recommend what to use to remove the old seal, adhesive etc…..I’m having trouble getting it all off, is there a substance that will help to remove it all?

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