Slot gaskets

[Corvida]

Last year I built a 12 foot rowing dinghy for a friend who has since gained a bit of 'ballast'. Because of this, it's become common for water to slosh up the daggerboard case when tacking. Looking into the problem we found two options, either lighten the captain, or install a slot gasket. So in our search for a gasket kit we found that apparently this isn't an American thing, or we're just looking in the wrong places. The only thing we've been able to find is replacement mylar in the US. And honestly I'm not sure what the best method is for installing one on this particular boat. It's a Bateau V12 build of fiberglass covered Okoume with regular marine top coat covering the epoxy. I'm not sure if I should try something adhesive or drill and screw some aluminum bar stock down.

So are slot gaskets just not a thing in the US, or is everyone making their own with some bar stock?

[Gerarddm]

Some people use them here, especially on racing craft. Rowan uses one, as I am sure other sail-n-oar types do as well.

[BBSebens]

Some heavy sail cloth works just fine. Two pieces, each folded over, so the creases meet in the middle. Or even can overlap. Secure on each side with a batten of something well screwed down.

Being that that it's a dinghy, is it in the water all the time? If no, it's not complicated. Is yes, some anti fouling measure will likely be needed.

[Corvida]

It spends most of its life on a trailer, so no worries about anti-fouling. I'm still curious if anyone has tried the 'adhesive' methods. It would make life a lot easier if it works, but I'm generally not a proponent of adhesive anything under the water line. I'm also a bit hesitant to go screwing things into the bottom of a boat if it's not the best way to go.

[Ben Fuller]

Adhesive is the usual racing dinghy method. Double sided sailmakers tape works pretty well to adhere mylar. If you are in an highly abrasive environment a layer of sailrepair sticky back cloth on top of the mylar. For the mylar, put it on, then cut a slot with a u knife and a ruler. If your DB / cb is fat it may get more complicated with a foil shape for the board.

Annapolis Performance Sailing may have slot gasket mylar. In the days before computers I used to get it from sail makers as pattern mylar.

[Thorne]

I'm interested to see how this works out, as I'm not sure that a gasket will help if the problem is water too high in the DB case. You could try some sort of inner sleeve around the top inside of the DB slot, assuming the top of the DB won't push it down or jam. Possibly something out of plastic foam (pool noodle) or similar flexible and compressible material?

[Richard of Woods Designs]

It is very unusual to need slot rubbers on a daggerboard, but on a centreboard they are almost essential.

How tight is the board in the case? is the slot profiled to match the board? I assume you are talking about sailing, not rowing when certainly you need a short daggerboard to stop water washing up the case

Richard Woods

[Otter99]

http://www.apsltd.com

Check out Annapolis Sailing Supply. They sell material especially made for the task. The right amount of stiffness and flex. I'm really happy with it on my Ness Yawl. It's pretty tough and holds its shape well. ~Dan