leaky wooden hatch

[Dayspring]

Advice please from all you shipwights out there. I had a hatch made for my plymouth hooker in her rebuild last year. It has unfortunately been an unmitigated disaster from the start - leaking like a sieve after warm weather and swelling up so much in the rain that I can't get out of the boat!

However help is at hand - and I'm having a new hatch built, starting next week. The original was Iroko with splines that were unglued. Can anyone suggest a better method of putting together the hatch so that it won't leak or swell so badly? I still want to use iroko as the rest of the hatch and deck is made from this. Would glueing splines make much of a difference? and if so, epoxy or resorcinol?

For most of the others I am having hatch covers made, so I don't have to have the entire 9 foot hatch rebuilt, but this is the sliding hatch and therefore can't have a cover.

 

[nmiller]

Hi
It sounds as though you have two problems. It may be possible to solve them both by laminating iroko veneers onto a plywood substrate, with the covering boards rebated from stock the same thickness as the finished laminate so that it covers the edges of the ply. The problem is that this might not solve the binding issue, which could be down to the design of the runners on which the hatch slides. As the hatch components are swelling and shrinking so much I would be concerned that glued splines may make the middle watertight but the swelling forces may break the joints in the covering boards in the corners. The ply laminate should be stable enough to prevent this problem.
Regards
Nick

 

[Dayspring]

Thanks, but plywood is banned from the boat! The runners are also being remade so that it can swell if needs be, without jamming - (it'll go over and round) and sit on brass runners. all the rest of the boat is very traditional - caulked and payed with jefferies no. 2. how were the old hatches made?

 

[FullCircle0]

Some of the old hatches were made with a gap in the top surface between the boards and above the loose splines, and this would be payed, in these days with a run of Sikaflex.

The theory was that a certain amount of expansion and contraction was allowed to take place without the dimensions changing (hence the binding).

I have a glued hatch (afrormosia) on my boat which I had made a year or so ago which wasn't made on the above lines and, like yours, it leaked and split etc. etc. For now, I have almost soaked it in epoxy and painted 3 more layers of thin epoxy over the top before varnishing....Not sure how it will go...all I can say is that my winter hatch cover of ply doesn't even drip, darn it!!!