Hatchea for watertight craah compartment

[Cheechako]

Commercial hatches are quite expensive. Google "Freeman Hatch", I think there are some fiberglass options with one of these places.
https://www.advantecglobal.com/marine/freeman-marine/
https://shop.hamiltonmarine.com/depa...CO.html?top=40

BTW, every cubic foot of air only gets you 64 pounds of flotation. So for a 10000 lb boat you need 156 cubic feet of air flotation. But I guess you are just trying to not fill the boat, which is a good thing.

[Cyrus Safdari]

Originally Posted by RaymondR

If you can put a plywood hatch with a soft rubber seal around the edge through the hole . .

Indeed but my question was A-whether theres a commercial producer of such hatch lids and 2- whether there was a source for a latch that wouldnt poke up into the vberth mattress over this hatch.

[Cyrus Safdari]

Originally Posted by Cheechako

Commercial hatches are quite expensive. .

Yes and heavy!! And ugly. these aluminum jobs are not what im looking for

Im not holding back a great vol of water not high pressure.

[Cheechako]

Originally Posted by Cyrus Safdari

Yes and heavy!! And ugly. these aluminum jobs are not what im looking for

Im not holding back a great vol of water not high pressure.

Yeah, but what they do well is NOT LEAK! I had one I put on the sole of my cockpit on my first cruiser. It allowed me to sit right behind the engine to work on it, or look directly at the stuffing box. On that boat it helped a lot.

I'm not exactly sure what you are doing other than trying to make a watertight bulkhead...? If so, could you mount a hatch that swung INTO the watertight compartment? That way under pressure it would seal tighter. (Like catamarans have the hatch in each hull for escape, they swing out and are just normal HD hatches....)

[Cheechako]

Originally Posted by Cyrus Safdari

Indeed but my question was A-whether theres a commercial producer of such hatch lids and 2- whether there was a source for a latch that wouldnt poke up into the vberth mattress over this hatch.

So one question is: Do you need regular access inside these compartments? If not you could take a regular hatch and cut the studs and add thumbscrews or etc to solve the "poke into the mattress" issue.

I cant remember for sure, but one type of hatch I had had levers that tightened as you turned (up inside the hatch opening) rather than project out much. I wonder if those are available...

[Cyrus Safdari]

Originally Posted by funjohnson

How often do you want access? We made ours watertight with a simple plywood hatch and gasket that was bolted down flush to a recessed lip. It took under two minutes to unscrew the roughly 16 machine screws whenever I need to get into the area.

Matt

Thank you, this is a uaeful point

[Cheechako]

Seems you could open these from the "inside". ?
https://www.amazon.com/YaeMarine-Mar...135970&sr=8-27

[Cyrus Safdari]

Originally Posted by Nani Kai

If it were me I would make the hatch lids with a 1/2" rabbit around the perimeter, then rout out a slot to accept a 1/8" 'O' ring. Then install flush deck marine hatch cover latches

Yes I was hoping for a commercial maker of suchhatches with the lip inside

However relying on the water pressure alone to seal the hatch, while great in theory, doesnt work out in practice becauas the pressure is not consistent or evenly distributed and sloshes around. So you really need a mechanism that tightens the hatch and compresses the lid gasket evenly all around. This isnt hard to do, just a star screw knob on one side of an oversized plywood panel-lid, and a threaded cross beam on the other, but I was hoping for a nice pretty commercially made hatch

[Cyrus Safdari]

Originally Posted by Cheechako

Yeah, but what they do well is NOT LEAK! I had one I put on the sole of my cockpit on my first cruiser. It allowed me to sit right behind the engine to work on it, or look directly at the stuffing box. On that boat it helped a lot.

I'm not exactly sure what you are ..)

And HOT thise aluminmum hatches on the deck or cockpit sole of a boat in the tropics can cook eggs.

I dont think I want to install deck hatches upsode down down in the vberth because aside from the fact that opening them would be impossible since there's no room to swing open, my brand new Lewmars deck hatchrs are ready leaking at the hinge, 6 mos after install.

[Cyrus Safdari]

Originally Posted by Cheechako

Seems you could open these from the "inside". ?
https://www.amazon.com/YaeMarine-Mar...135970&sr=8-27

Thank you, almost

but there is no room to swing a hatch lid open down into the compartment space. You can only jiggle and lift lids up and out.