Self-Draining Cockpit

[Finesse]

I have a Finesse 24. Unfortunately the cockpit floor is not water tight and the engine is directly beneath it. Consequently, it is constantly wet, to the detriment of the motor. It is also necessary for large areas of the sole to have to be lifted to start the engine, to get at the seacock, fuel etc. The sole is pretty well level with the waterline and I had proposed crossed over drains through the hull at the turn of the bilge. Acess hatches would need to be large as all service items are scattered around the motor.

Any one have any experience of tackling such a job?

 

[Mirelle]

Yes, and it was a lot of effort and made several bits of boat hard to get at.

I would not bother, but would concentrate on making the hatch over the engine rain proof and fitting a good cockpit cover when she is on the mooring.

 

[PBrooks]

And another thing! I think you will need to raise the floor so that it is several inches(around 6in?) above the waterline, with a slope towards the drains, otherwise it won't be self draining. Mirelle's advice is probably the best.
Best regards
Paul

 

[Mirelle]

I should perhaps add that I did the operation on the last boat. Mr Brooks is right.

Now, the boat I have now was built with a small self draining footwell, in accordance with 1930's ideas of robust seaworthiness (crew may get washed off, but the boat will be fine!). In 18 years I have filled the cockpit once, and frankly a boat with a non-self draining cockpit would have been OK, since the head of a sea that did come aboard would have drained to the bilge right away.

 

[Guest]

I was party to a conversation with Alan Platt (of Finesse Yachts) a number of years ago about self-draining cockpits. He believed that the non-watertight sole of his cockpits would allow water to be distributed throughout the bilges so ensuring the boat would float level until the water could be pumped out. I'm not sure that I completely agree with this, but it is an interesting perspective.

 

[Finesse]

Thanks for the replies. Looks like a cockpit cover then!!!

 

[Mirelle]

It will pay for itself in saved varnish, as well!

Seriously, it is worth it; do whatever you can to keep fresh water out of the bilge. Self draining cockpits rot with monotonous regularity; apart from mine I can think of four other boats moored near mine, built between the 1930's and the 1970's, which have needed a total rebuild of the self draining cockpit.

Consequently, I now have a cockpit cover over the rebuilt self draining cockpit!

 

[spark]

>>Self draining cockpits rot with monotonous regularity; apart from mine I can think of four other boats moored near mine, built between the 1930's and the 1970's, which have needed a total rebuild of the self draining cockpit.
<<

I'm interested to know what sort of wood was used in these (the originals that rotted, that is) and what was the finish on them (paint? varnish? ...?)

 

[Mirelle]

Pitch pine (mine), mahogany, iroko, marine ply, all usually on oak bearers. Some painted, some with lead linings (mine), some with GRP lining.

My rebuilt specimen is plywood sheathed in glass cloth with very generously filleted corners and a slope down to the twin, crossed over, drains, and it is a mere footwell. It has lasted ten years and is still OK.

I fancy the problems start with clever designs. a very simple footbath with seats at deck level and no openings will do better than anything fancy.

 

[spark]

I would have expected the pitch pine and iroko to have lasted OK but the linings must have done for them. Rainwater will almost certainly find its way between the lining and the wood - a great place for rot to get a hold. Poorly maintained paint will have the same effect.

The problem is fresh water lying where there is insufficient air to inhibit the bugs.

A solid wood construction, built using epoxy glue (for watertightness), with proper drainage (i.e. a positive slope down to the drains) and finished with a good preserving oil (Varnol, Deks Ojle #1, etc.) will do the job just as well as, if not better than, your ply/glass solution.

 

[Mirelle]

I respectfully beg to differ, slightly at least. I agree that the problem is damp corners where air does not circulate, but I think that 90% of the problem is clever designs, with hatches, seats below deck level with lifting lids, little drains unthat get blocked, and so on. I would not be at all comfortable with using solid timber and epoxy; if there is one part of the boat which alternates between wet and dry, causing movement in the timber, it is this area. I would not use epoxy with solid timber and I have never seen it recommended in such an application.

 

[spark]

We'll have to leave it in a state of happy disagreement, then. I've built several cockpits using solid wood (iroko, larch, oak) and epoxy and all are, as far as I know, still in service and still watertight. It seems to work fine.

I agree that the design detail of the cockpit is important. Water must be free to run from all points to the drains or trouble will surely come and visit.