Hatch gasket?

[MisterMoon]

Ok, so I put a hatch in my foredeck where there was none. What's the collected wisdom on gasket material? 

 

 

[makenmend]

 I'm using 1/8" X 7/32" rubber weather seal purchased at Lowes,worked out good
for my flush fit kayak hatches. Just put on my Core sound seat hatches (built
per plan)but until I do capsize tests not sure how well they'll seal.
 

]

 

[Peter HK]

I used this stuff

https://www.whitworths.com.au/main_itemdetail.asp?cat=156&item=191312&intAbsolutePage=1

When I did the capsize test only a few drops came in the seat hatches. The foredeck hatch was above the capsized waterline and the boat would have to turn turtle to test it. I've never had a drop in the forward locker from waves.

Cheers

Peter HK

[Hirilonde]

I have done hatches with rubber gaskets like this http://www.mcmaster.com/#bulb-seals/=lorufg

 

Depending on the type of rubber used, I like EPDM, it can be glued into a channel with contact cement.  The channel need only be shallow, but it protects from pulling the gasket off while accessing the hatch.  This is a bit more of a project, but seals well, lasts, and looks good.  Foam tape will likely need replacing often if the hatch is used a lot.  Though replacement is so easy, and your roll of tape will probably have plenty extra, so this is not a big deal.

[PAR]

I usually make my own gaskets, if an odd enough shape that makes bending a rubber gasket tough. I cut a shallow groove with a round or V bottom router bit, then I tape off each side of this groove with masking tape, building up a several layers. This becomes the height of the gasket, so use several layers of tape. Then I fill the groove proud with 3M-5200 or a similar adhesive/sealant and trowel it off flush with the top of the tape. Lastly I remove the tape, which presents a built in gasket/O ring that will take compression well. Naturally, you'll want a well fitting hatch or a tall gasket, to take up any irregularities. The foam rubber ones from the big box store do work, but usually let in some water. The rubber tube style gaskets (bulb seals) work well too.