Sealing Hatches with gasket material

[bencvalley]

Hello everyone. I have a bit of a problem and am as ignorant as can be. We're sealing the hatches on a catamaran we are building. The door sits on top of the hatch and has one seal inside lid of the door, and one on the outside edge. Because the cornering tool for gasket material is some $600 dollars, we didn't buy one, and simply cut 45 degree angles on four strips of gasket material. We glued them down with contact cement, but the cement was not able to keep the corners glued together, they pulled apart and now all the corners have gaps. The interior seal is probably adequate to keep water out, but we'd like the redundancy of the outer seal working too obviously. Any ideas that don't involve starting over and making an attempt with one piece? Thanks for and help, and yes, we are terrible at building boats just in case anyone was wondering. Thanks for any thoughts.

[Orion Jim]

May be a simple issue. The gasket material was cut too short for the application, or the contact cement was not applied to clean surface. (You apply the adhesive to BOTH sides, wait for it to get tacky, then pinch them together for a minute) I have similar butted joints that have lasted for many years. No indication of separation.

[UNCIVILIZED]

I can't say for certain that it would work, but I'd be tempted to try one of the adhesives that come in a tube. Including some sized for caulking guns.

The other thing which goes through my mind is one that's applicable if you have to start over. And that's to cut a small notch in the material where each corner is, so that when you bend the gasket material 90 degrees, the notch disappears. Though it still might need gluing together at the joint. It's but an idea, & one that I've not tried.

[SV DestinyAscen]

Don't cut the gasket all the way through.

What you can do is measure the entire perimeter and do it in one piece and instead of starting the gasket at the corner, start the gasket at the perimeter the edge that faces the hatch hingles.

This requires a little geometry, but basically measure the corner you're trying to turn with the gasket material, imagine the corner as anequaliteral triangle, and you'll exactly half of the equaliterall triangle on each half of the gasket corner such that when you fold the gasket, the two halves come together to form a triangle around the edge.

[Cheechako]

There are better glues for neoprene gaskets than contact cement. Trying to remember, but I think model airplane glue or 5 second glue. Where I worked we used to use it on neoprene Orings to 6000 psi! It welds the rubber to itself rather than just "gluing" it.
I cant tell the size or flexibility of that gasket, but I would likely wrap it around all corners in one piece and join it on a straight side.

[Ziggy]

Do you know the gasket material? If it's EPDM rubber, most adhesives won't work. Try Silaprene Adhesive Sealant M6325, available from JD Industrial Supply.

If it's neoprene, try an adhesive meant for repairing wetsuits, like Neoprene Queen. Silaprene may also work on neoprene, but I haven't tried it.

[Ziggy]

Do you know the gasket material? If it's EPDM rubber, most adhesives won't work. Try Silaprene Adhesive Sealant M6325, available from JD Industrial Supply.

If it's neoprene, try an adhesive meant for repairing wetsuits, like Neoprene Queen. Silaprene may also work, but I haven't tried it.

[puffcard]

https://www.amazon.com/3M-08008-Blac.../dp/B00063X38M

[snort]

I had a similar issue and used BoatLife Life Caulk to fill that little gap. Seems okay now.
I might be persuaded to try this other BoatLife product though: https://www.amazon.com/Boat-Life-Lif...ife+life+caulk

Your work looks fine!

The only thing I might add to your hatch is a pair of latches on opposite sides to secure the hatches to the boat.

[scherzoja]

Yep,

I used this stuff to bond edpm gasket to the aluminum hatch and it stuck really well. I know because I had to remove it all (after a dumb mistake) and it was very difficult getting all the gasket off that frame. Came off in pieces and I had to use solvents to dissolve the rest, which was also very difficult. I ended up sticking a wirebrush in a drill gun and using that to get the stuff off.

Not sure how well it will bond the rubber pieces together, but it probably will do a good job.

Also not sure the difference between 8008 and 8011

Here is what I picked up from local auto parts store

3M Black Super Weatherstrip Adhesive #08011

3M 8011 - Weatherstrip Adhesive | O'Reilly Auto Parts


Edit: If those seals had their own sticky-back to them, you might want to take a close look at the longevity of that stick-back substance; they might unstick after a some time, esp. in the heat. I tried some self-stick gaskets from McMaster and it didn't really hold well, then switched to 8011.

[donradcliffe]

Just caulk the damn crack and drive on.

[slowpoker]

Yes; Fill the space with Permatex Ultra Black maximum oil resistance RTV silicone gasket maker PX# 82180 sold at Walmart automotive section. Less than $5 a squeeze tube and is black in color and can be used as a gasket maker material very resistant to oil like on the engine gaskets, electrical wiring sealing, etc. bonds and seals like silicone. If you mess up, it can be cut or scraped off. Nice stuff for fixing rubber things, engine hoses wires that stick out, etc.

[Mischief_Inc]

I ain't tried it (yet) with hatches, but have with other things. Which is that you can put a release agent, or barrier (packing tape) onto the knife edge on the hatch, prior to adding "gasket in a tube" in the gap at your corners. Then once the goop is in place, & is just beginning to kick, set the hatch in place, so that it's weight lets things form perfectly to it's rim as it finishes curing.
So that when dogged, everything already has 100% contact, & the dogs then compress everything fairly evenly. Or mostly evenly, as if there's a difference in shore humbers between the gasket material, & the goop you use, then the softer one will compress a bit more. Though for small areas like this, such likely isn't critical.

What I'm saying, is to treat it kind of like casting bases for hardware & other bits using epoxy/epoxy bog. So that you get a custom formed seal. There's plenty of info on how to do this with epoxy in the Gougeon's book, & via WEST Systems (& others).

[foufou]

Or try polyurethane adhesive caulk. I have had very good luck with Home Depot products. The cure time is long. Use a pinch clamp for a few days. Good luck ��

[salticrak]

I did this with my fishing kayaks hatch.It works well.The kayak I and I often get wiped out in open beach surf launches so the pressure of breaking waves and turning turtle have not allowed a drop of water into the hull.