Resealing a hatch

[DAVID BLOCH]

My dilemma: I thought I had to remove a Lewmar deck hatch. I ran a knife all the way around the rim, cutting into the silicone seal anywhere that it was not too tight to get the knife in. That wasn't enough; I was not able to break the seal and did not want to try to lever the thing out with so much force that I'd break the fiberglass.
Now it turns out I don't have to remove the hatch at all. So my task is to reseal that silicone that basically has been sliced all the way around.
My thinking is to use "flowable" silicone around first, in hopes that will flow into the thin slice; then use proper sealant over that. But anyone have suggestions on it? Thanks!

 

[KD3PC]

you can certainly try the "flowable", but I doubt it will last. You really need to pull the hatch, clean up and reseal. Sealant over sealant, even the same brand/type seldom helps for more than a week or so, especially if this hatch is in direct weather.

To pull it, warm up the ring (or wait for a hot day)....take some small hardwood wedges or thin chainsaw plastic wedges and gently push one in lengthwise against the rim, on all four sides at the same time. Every 15 or 20 minutes tap them a little further...and in an hour or two it will be high enough to run the sharp knife all the way through the sealant.

 

[thinwater]

Which is why I would put it back in with butyl.

The last time I had to replace a hatch (cracked lens due to stepping on when latch was in the opening) took about 15 minutes, start to finish. I had a spare on hand, removed the fasteners, cut the butyl, scraped, applied new, and replaced. The rain started in 10 minutes and I was glad there was zero drying time.

 

[alexco38]

Remove the hinge. Two Philips flat-head screw on each hinge you are out.

You need to clean up the old silicon real good, get Silkflex 279UV and the primer.

Since it is on the bench anyway, replace the lens. I made a plywood cover for the hatch. It's a winter job.

 

[DAVID BLOCH]

Thanks for the responses!

KD3PC: thanks for your comment on the flowable stuff; I think you've convinced me that I have to pull the whole thing out. I'll ask the hardware store about the wedges; not something I've ever seen before.
THINWATER: what's Butyl? Can you tell me more about that? Maybe send a link URL if you've got one.
ALEXCO: Just removing the hinge won't do it for me, and this one isn't put together that way. (Hinge pins are driven way up inside the frame and take a hammer and pin punch to knock out.) Thanx for the info on Silkflex; that's a new name for me, too.
This is a summer job for us; we live aboard and have 4 months with no rain (San Francisco area) each summer so now's the time. I've got my plywood covers handy anyway.

 

[KD3PC]

This is a summer job for us; we live aboard and have 4 months with no rain (San Francisco area) each summer so now's the time. I've got my plywood covers handy anyway.

We were liveaboard when I did mine, not a big deal If you have the replacement hatch, it is a two hour job with the butyl that MaineSail brokers here on this site. Maybe 6 hours if you have to redo the screw holes and chipped coach house where it is mounted. I took West epoxy and filled all the screw holes with a syringe. Several took a table spoon or more before running out, so the ring/core took some. I waited till the epoxy set, then faired that part so the butyl was on smooth, clean glass.

I made a "patch" out of plywood, some old vinyl siding and three trash bags. Boy it sure darkened the fore cabin when I tried it our, but we finished before dark and had a water tight hatch.

Best of luck.

 

[rpwillia]

Get this stuff

IMHO, Best stuff out there.

http://www.pbase.com/mainecruising/butyl_tape

 

[Gunni]

David, I have never seen a Lewmar hatch hinge pin that requires "a hammer and pin punch" to remove. You sound like you are about to make a hatch re-bedding into a full-blown hatch replacement. I suggest that you visit Lewmar.com and research this job before going any further. They post an extensive library of product literature, including instructions for hatch lid removal and adjustment documentation.

They also have documentation for the hatch frame bedding job. You need to do this job right or you will incur a very expensive hatch replacement, a leaky boat, damaged deck coring, or all of the above.
Good luck!

 

[DAVID BLOCH]

Gunni wrote:
"David, I have never seen a Lewmar hatch hinge pin that requires "a hammer and pin punch" to remove."
Believe me, that's really what it takes. The pins are very thin, and (in the case of the Size 60 hatch) quite long. To get the "lid" of the hatch off of the rest of the assembly does require driving those pins out by inserting a punch into a very small access slot. (You can use a screwdriver but have more chance of mangling the end of the pin than knocking it out.)
At this point, from everyone's advice here, I'm going to go ahead and replace the whole thing. It's 17 years old and if I'm going to go thru all the trouble of resealing, I may as well end up with a new one! The new Lewmar "low profile" is supposed to be a drop-in replacement for the Coastline model.