Hatch. Sealant or gasket?

[Stuart 28-2]

Hello all. I've been saying for about 5 years but I'm new to sailboat ownership. I have a1988 Ericson 28-2. See images of my Lewmar hatch. For sealing between hatch and deck I have not found any gaskets on offer or even reference to using a gasket or seal for this. Is the intent a seal or sealant? I know people often use sealants like 3M 4200 for this job. However, looking at the design of the hatch I really don't think it suits piling a whole load of sealant in there, or, maybe it's not the original hatch and it doesn't suit the boat. The hatch sits flat on the deck and both sides of the seal recess are the same height meaning there would be a very thin membrane of sealant between hatch and deck. If I'm supposed to find a gasket/seal can someone please advise me if the intended type. It's a Lewmar hatch.

 

[Stuart 28-2]

That should read "sailing for 5 years" not "saying"

 

[Dave G.]

If it were me I would use white butyl tape but some do not like the ooze that may occur. Easy enough to clean though and seals exceptionally well without gluing it all together.

 

[Christian Williams]

The intent is sealant, not a gasket. 4200 is fine, so are other low adhesives. Butyl tape is OK, but I prefer it for small jobs.

Use plenty of sealant--that's what the recess in the mating surface is for. Mask with painter's tape to make clean-up easy.

 

[goldenstate]

I did two hatches last summer with butyl tape from Compass Marine. I would try sealant next time around.

 

[JSM]

Although some may scoff at the idea, four years ago I re bedded a Lewmar hatch on our 34-2 with exterior grade door and window sealant as it was all that I had on hand at the time.
Still no leaks.

 

[Stuart 28-2]

Thanks to all for the advice.

 

[c.gustafson]

I rebedded my Lewmar hatches with Life Caulk --- not a single drip of water leakage. As Christian advised, put down painter's tape to help with the clean-up. And to state the obvious, when you first put in the screws, don't tighten them all the way. Come back in 24 hours or so, after the caulk has set up a bit, and then tighten a bit more.

 

[Loren Beach]

We re-bedded all of our hatches recently. Sikaflex 291 LOT.
Tightened all screws all the way down. Cleans up with paint thinner. Use... a lot... of paper towels.... and wear vinyl gloves.

During the dry-fit, also check on how tight the screws go in, just to be certain that you do not have to epoxy and re-drill any holes. We actually epoxied in all the holes oversize and redrilled them, to protect the core in the future.
I have some notes about this in our blog.
(We had a hard rain recently for a day and found zero leaks around any hatch or port.)

 

[Mr. Scarlett]

A good tip when bedding hardware: cut up rags into 2" squares and have them standing by in a bag/container. Same with your solvent of choice and a garbage bag/container. After tightening - it's one square, one dip, one wipe, and into the garbage. Repeat until satisfied.

Something else for those who like a "gasket" and those who like to tighten all the way: you can goop up both sides of a washer to go between the hardware and deck. Tighten all the way and you still have a thin, even layer of bedding compound.

 

[garryh]

"I did two hatches last summer with butyl tape from Compass Marine. I would try sealant next time around."
why..? what was the problem(s) with it? I plan on using the Bed-It tape.

 

[goldenstate]

"I did two hatches last summer with butyl tape from Compass Marine. I would try sealant next time around."
why..? what was the problem(s) with it? I plan on using the Bed-It tape.

Here's my blog entry about it:

E32-200 - Re-bedding Lewmar hatches and mast collar with Compass Marine Bed-It butyl tape

Total hours: 12-15 hours, on multiple days Cost, $50 for butyl tape. $40 for Debond cleaner (only a little used on this job) Early July, 2020 It took some detective work, but after a careful review of the evidence, I suspected I had a leak or...

ericsonyachts.org

The butyl tape can be fussy to work with. If you get everything clean and lay it down properly the first time, it works great. I decided to put two layers of the tape down for the hatches as the single layer didn't seem to fill the sealant gap adequately. Once one starts squishing butyl on top of butyl, then making adjustments, the stuff starts sticking to your fingers or gloves, it gets out of line.

On the other hand, the tape won't drip while you're installing it, and my hatches fit snugly into my hull cutouts. I had to wiggle them into place. Maybe butyl tape was easier in this setting process than goopy adhesive would have been.

I think each material probably has upsides and downsides as a sealant. A tube adhesive is probably easier for the "squirt on generously, then clean up the excess" approach.

The whole job is the kind of pain in the neck that you want to work right the first time, especially if you bed with an adhesive sealant like Sika 291 or similar. Prying up the 30 year old hatch without bending the frame or breaking gel coat was probably the hardest part.

Good luck - let us know what you choose and how it goes! There's no perfect answer.

 

[Mr. Scarlett]

I've heard some people complain that butyl gets a little "runny" and the area around the piece needs continuous wiping up. I do like the idea little noodles of butyl in countersunk holes in the deck and under the heads of screws, although I haven't tried it myself.

 

[Dave G.]

I would imagine you don't plan on having to do that job again anytime soon so even 4200 would work. I just personally hate "gluing" stuff together for fear I will have to get it apart again in the near future. A lot of car manufacturers use butyl to seal windshields into the frame and that seems to work out well. I've never had butyl get runny even in hot weather so don't think that will happen.

 

[Stuart 28-2]

A good tip when bedding hardware: cut up rags into 2" squares and have them standing by in a bag/container. Same with your solvent of choice and a garbage bag/container. After tightening - it's one square, one dip, one wipe, and into the garbage. Repeat until satisfied.

Something else for those who like a "gasket" and those who like to tighten all the way: you can goop up both sides of a washer to go between the hardware and deck. Tighten all the way and you still have a thin, even layer of bedding compound.

That was a great tip on the 2" rags. Very handy, thanks.

 

[Stuart 28-2]

I ended up using white butyl tape. It worked well and there are no leaks so far. The tip to refrigerate it first is a must. It was easy to apply at first but got difficult for the last bit as it warmed up - got very sticky. I wouldn't use it in cases where you don't want any ooze out as you can't make a nice bead like with sealant.