making a waterproof cockpit hatch (in the floor)

mikecontessa26

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hi, i need to replace/rebuild the current leaky seive access panel on my cockpit floor, it's currently 6mm grp. I need the hatch there for occasional access to the oil filer and exaust silencer.

I'm thinking of replacing the current cockpit floor with a new epoxied marine-ply one and making a new access panel as there's no-way to bolt the existing one down.

My question is whats the best way of sealing this hatch? I don't really trust dry-rubber seals, they always seem to leak, i'd rather use Sikaflex but i'd never get it apart again for access.

Any ideas?
 
Somebody on another thread was talking about Sikaflex292??? Doesn't set hard by all accounts??
 
[ QUOTE ]
hi, i need to replace/rebuild the current leaky seive access panel on my cockpit floor, it's currently 6mm grp. I need the hatch there for occasional access to the oil filer and exaust silencer.

I'm thinking of replacing the current cockpit floor with a new epoxied marine-ply one and making a new access panel as there's no-way to bolt the existing one down.

My question is whats the best way of sealing this hatch? I don't really trust dry-rubber seals, they always seem to leak, i'd rather use Sikaflex but i'd never get it apart again for access.

Any ideas?

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My cockpit sole is a large ply batten reinforced sheet with treadmark glued on. It sits on a raised coaming lip to provide a channel all around for water to run to aft drains. It leaked like a sieve.
I tried various ways to seal it down but needs to be non-permanent to allow me to the shaft etc.

Solution- local DIY store. Wide B form window / door self-adhesive rubber seal. I cleaned of the coaming lip. Stuck the strip down and then put cockpit sole down and screwed it up. Bingo - solved. The strip comes in 3m, 6m and 10m rolls ... worked for me. Less than half the price of so called hatch sealing strip at chandlers ...
 
Hi LNH, I fitted a similar plastic hatch in boat years ago but I had to re-inforce under the lid as it flexed a lot when stood on. If you can see it in the flesh, and stand on it, you will be able to see if it will be strong enough.
 
i'm not too worried about being able to stand on it as the cockpit grating will take the load either-side of the hatch.

Did it keep the water out?
 
I have one of those so-called stand-on plastic inspection hatches and it certainly won't take my weight, albeit considerable, and if you jumped down on it from a cockpit locker you'd go right through. The hinges are pretty flimsy as well. I have another small hatch in the cockpit that is simply a piece of ply in a rebated frame secured by screws and I seal that with Sylglas tape- works a treat and is easy to remove.
 
I have had the same problem with ingress of water through the cockpit hatch. now had one season of a pefectly dry bildge, simply by putting a 2" wide- 1.2" deep fiddle around the entire floor then leaving a gap of about 2" around sides for drainage ,works a treat.
 
The whole of my cockpit floor is hinged to give engine access. This is standard on a Virgo Voyager. The hole consists of a raised lip all round that forms a gutter to drain water away to the cockpit drains. The cover is a piece if marine ply abourthalf an inch thick hinged on one side and screwed down by two clamps. The seal is self adhesive neoprene about 1" wide in one continuous piece with a diagonal cut butt join at one end.

I get virtually no water ingress at all under normal circumstances. I did get a little leakage when the yard put my boat on the hard and unfortunately had the boat in such a way that the cockpit drains were on the uphill slope so water accumulated at the other end of the cockpit. So over a period of days there was some leakage.
 
That's the solution I used on mine. Never leaked, even when being pooped at sea. Don't make the mistale of haiving a rubber strip that is too wide. The narrower the strip (within limits) allows you to get higher pressures on the seal and keep the water out.
 
Hi, from memory it did keep the water out. My current boat has a lip all round making a channel all round to the drains at the rear of the cockpit. The top is in two halves, the rear half fixed with several coachbolts and the front half hinged for engine access. All on sponge rubber, with the hinged half held down with heavy 'Hold Down' catches from Timage - expensive but work well.
 
Our Maxi had a bolt down hatch in the cockpit floor for access to the back of the engine and sail drive. There were 8 6mm bolts and a seal about 20mm wide stuck to the hatch (Seals+ sell similar stuff) with a serrated surface made of a neaprene foan material. Never had any leaks but it did sit on a 25mm raised coming. Our current Moody has the whiole cockpit floor as removable though I have not tried that yet, there is far to much to disconnect to make it worth the effort.
 
I bought 2 x 5" diameter inspection rounds to fit one to cockpit sole so I could check easily all ok under there without the kefaffle of lifting the sole. All you do then is half turn of centre plate ... lift way and look see .. all OK - put back, half turn and locked.
 
I recently bought a sheet of grey UPVC and have used it to make temporary locker covers/ washboard/ various other bits of wooden trim that are just going mouldy whilst the boat is laid up. I have a big (about 2' square!) inspection hatch in the cockpit floor made by a previous owner and have also used the UPVC to make a temporary cover for that. 15mm thick is incredibly heavy but PLENTY strong enough to stand on. 10mm would probably be OK. Doesn't look pretty but is zero maintenance and was surprisingly easy to cut with a hand held circular saw.
 
Seals can work, but the self adhesive type rarely do as they move. For a selection of profiles look here. Something there will fit with the lip you can design on your new epoxied hatch. The 2 part adhesive is a pain, you have to mast the surrounding area etc but it's a proper job. Note pyrojames excellent comment about seal width.
 
Current practice in small fishing boats: a GRP hatch lid with turned down edges sits on a rubber seal in a groove, which is drained via flexible pipes either side to skin fittings. The hatch is held down with four bolts, the heads in cups, tighten down with a socket. This is good enough for MCA requirements. Alan Baumbach, 01736 753228 is a boatbuilder who can give you the detail, I think it's possible to buy the whole thing, hatch and housing.
 
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Seals can work, but the self adhesive type rarely do as they move. For a selection of profiles look here. Something there will fit with the lip you can design on your new epoxied hatch. The 2 part adhesive is a pain, you have to mast the surrounding area etc but it's a proper job. Note pyrojames excellent comment about seal width.

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3 years and window self-adhesive seal strip still in place.
 
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