slot gasket

chalky · 15 Apr 2008, 08:40

Please help. My last task this spring is to fit a new slot gasket to Rising Damp. Should I glue the gasket in place, then cut the mylar on the centreline or mark and cut the mylar on the bench and stick to boat ( holding edges together with tape?) . If I cut the slot when stuck to the boat, any tips on how to cut a straight line? Any general slot gasket advice ? Hull looks much better without bilge battons. Too many screws in keel that I couldn't remove....

johnk · 15 Apr 2008, 09:36

I saw John Meadowcroft's new boat get it's slot gasket put on at BCYC. His boat has no keel. The mylar overlapped about 2mm and was put on in 2 separate strips. The strips were glued on with "Bison?" contact adhesive. Masking tape about 12 mm wide was used to control the glued area on the hull. No glue was put on a 12 mm strip at each side of the slot. This meant that the gasket could take a 12 mm radius curve when the centreboard was out of it's case. I hope this makes some sense.

If your boat has a keel, I guess that the problem is that the keel is not wide enough by the centreboard case to safely glue the mylar and leave the 12 mm unglued width. I cannot help any more on this. Good Luck with the job.

MikeDay · 15 Apr 2008, 10:36

There's previous advice on this subject on this discussion board. Put 'slot gasket' into the search facility and look at all previous entries and you'll find lots of useful tips.
Mike D
N3496

John Meadowcroft · 20 Apr 2008, 09:55

I must advise that new gaskets disappeared completely during a one hour sail in waves on saturday. My plan (should anyone believe that they should follow it...) to sort the problem is to re apply new gaskets in exactly the same way as before (johnk gives a pretty accurate description) but this time to abrade the hull with more vigour before doing it. I think that the contact adhesive stuck to the polished paint rather than to the hull and this is why they parted company.
I will try to remember to keep this thread updated with what happens next...
John

chalky · 21 Apr 2008, 08:43

Thanks for advice on new gasket, plenty of information on discussion board. However mylar gasket failed due too tight an angle between horizontal face of keel and vertical centreboard (very narrow keel). Glue (sticks like sticky stuff) worked perfectly holding mangled and creased pieces of mylar firmly in place, preventing centreboard going back into box! Have now fitted sailcloth gasket (couple of quid from local loft for some strips of dacron) beneath remains of salvaged keelband. Works perfectly! Now time to go racing at the weekend.

Derek · 22 Apr 2008, 07:15

If you are sailing a boat with a keel, it might be worth considering the oldest of methods.
Find some low profile keel band and screw it on with the slot gasket underneath. The weight and drag are negligible compared to the drag you get trawling 2m of mylar!
It is always going to be a problem to glue gasket on for boats with a keel. The area available for adhesive is only about 10mm wide and unlikey to last long.
Sailcloth being less rigid than mylar is an alternative too....

Crusader 3244 · 18 Mar 2009, 08:37

ping:)

Tim Gatti · 19 Mar 2009, 10:29

I'd agree with use of keelband as well as contact adhesive to anchor slot gasket on boats with keels - but if anyone's buying new be aware - it's not cheap. As for cutting slot in mylar variety. I always tape it to a flat board and pre-cut it with a straight edge and a trimming knife prior to fitting. TIP: before you take it off the cutting board, run a length of masking tape down the line of the cut to hold it all together - it makes fitting it much easier. But remember to peel the tape off once the gasket it in place or you may struggle to get your plate down when you relaunch! Another tip if you're using mylar - fit the plate before the slot gasket. The stuff's incredibly stiff and trying to jiggle a plate into position to locate the pivot bolt is nigh on impossible with a new gasket in place. Tim

chalky · 19 Mar 2009, 08:00

I replaced the slot gasket on 3232 last year. the first attempt was a mylar gasket held in place with "no nails" and keel band. looked very tidy and was securely fixed. However the the mylar could not bend to a tight enough angle between the remaining keel section and face of the centreboard. It became kinked and was dragged backed into the centre board case when raising the board. When removing the wreckage all the paint and in places some of the wooden fibres were removed. Resorted to sail cloth gasket which works very well and was how Rowsell brothers intended the gasket to be fitted. Good luck!