Leaking Lewmar "Ocean" Hatch

[sailcrazy]

Following. Our old Lewmar hatches (1989) are all problematic, although only one leaks when we take green water over the bow...i think the frame is sprung! Our problem was with the hinges, and holding the hatch open. We finally resorted to installing a lid spring in each one....it holds the hatch open, and its easy to flex it in the middle and the spring folds as the hatch closes. Only 2 positions...open, or closed...but it des stay open without fail.

[poiu]

Dockhead, I’ve struggled with hatch leaks too. In my case a mixture of cracked seals and leaks through the acrylic and leaks through the lid to frame seals. I tried to replace the seals, but it is not easy on old hatches and we broke link pins pulling them apart and the resulting repair wasn’t perfect. Considerable practice is needed to get a nice job, so I’ve decided to replace them all with new, but just the lids as the base frames are OK and don’t leak.

If you want to try to replace just the seals I have plenty you can have. Medium and low profile hatches only. Newer type. Just say.

You can get the lids from Defender in the US, but not in the EU as far as I can tell. Half the price of a complete hatch and an awful lot less work. I ordered a few spare hinge pin sets also as the old ones were corroded and I didn’t expect to get them apart intact.

Parts are on a ship as we speak, so the saga isn’t yet over…

[bbalan]

Dockhead,
Sorry to see this late. I do not recommend buying a new hatch -- even though you already did. I put 8 lewmar ocean hatches on my trimaran when I bought here in the 90s. They mostly worked great for many years. During a major refit in 2013-14, we replaced 3 hatches. The replacements were not as good as the originals and had fitting and some leaking problems. Replaced a 4th in 2022. Same hatch, same part # (Ocean 70.) First one delivered with bent frame. 2nd one would not fit in original cutout. Amazingly, screw holes were also in different places! When asked about this, Lewmar said that happens sometime. Had to fill over half the holes then overdrill, fill and drill new holes. The quality and quality control of their hatches is terrible compared to what they used to make.


As for stopping a seal leak... a thin layer of black silicon, then close hatch, let it dry. Works for quite a while.
Cheers,
Bruce
s/v Migration

[Franziska]

One more thought, most hatches are closed tight by moving the handle so that it squeezes on the Aluminium frame.

If the seal has lost flexibility you can change the seal, or you could try to take the handle apart and sand off a tiny bit of the plastic axle, so that it's a tiny bit shorter. Reassemble and you have increased pressure on the seal. That should work, no?

[SV_FlyingTigress]

I have installed several ocean 60's this year. Some advise is use sufficient goop. I have tried 4200 and LifeSeal which I am currently using. After checking that the frame is straight with a straight edge put sufficient goop on it that the stuff oozes around the hatch BOTH all around the deck outside edge AND *all* around the flange on the inside. A complete bead. On leaking hatches, many I pulled (older lewmar medium/small) were leaking around the frame due to failed, insufficient and thin beads of sealing material. I really liked LifeSeal black. Then don't tighten it down ALL the way for 48 hours and do the final tightening after that. THAT is how much sealant you should use on every hatch. It is a mess but it works and helps handle slight irregularities i the mating surfaces. I have had success with resealing acrylic lenses with DOW 795. Stuff takes FOREVER to fully cure (14-21 days) but it is beautiful to work with and flows nicely and seems to be extremely resilient and "rubbery". Just don't be rough on the lenses while it is curing; don't take it into "sporty" sea conditions for 21 days. But the results seem very solid.

On a separate note, for my big Privilege cat side "windows" I use 795 to stick my large 10mm acrylic windows which glue to the sides of the catamaran hull without any screws needing to go through the acrylic. To hold vertical windows in place I make a wood "L" shaped pieces where the distance between the long leg of the "L" and the end of the short leg is the thickness of the lens (in my case 10mm plus the thickness of a chopstick pieces which I insert about 3/8" under the acrylic hold the window away from the hull to allow for sealant thickness while it dries. ). The "L" brackets are screwed into the hull just beyond the boarder of the window with the long side holding the acrylic and the short side as a standoff off the hull. I screw them into holes that I make in the area where the future and final 795 bead will cover the screw holes. After about a week, I remove the chopsticks and fill the shallow holes in with 795. After 2 weeks I remove the "L" support brackets and run a fresh, nice bead of 795 around the window. It is a bit of a pain, but it is the only way I have found to get nice results on large cat windows on vertical surfaces.

[Dockhead]

Originally Posted by SV_FlyingTigress

I have installed several ocean 60's this year. Some advise is use sufficient goop. I have tried 4200 and LifeSeal which I am currently using. After checking that the frame is straight with a straight edge put sufficient goop on it that the stuff oozes around the hatch BOTH all around the deck outside edge AND *all* around the flange on the inside. A complete bead. On leaking hatches, many I pulled (older lewmar medium/small) were leaking around the frame due to failed, insufficient and thin beads of sealing material. I really liked LifeSeal black. Then don't tighten it down ALL the way for 48 hours and do the final tightening after that. THAT is how much sealant you should use on every hatch. It is a mess but it works and helps handle slight irregularities i the mating surfaces. I have had success with resealing acrylic lenses with DOW 795. Stuff takes FOREVER to fully cure (14-21 days) but it is beautiful to work with and flows nicely and seems to be extremely resilient and "rubbery". Just don't be rough on the lenses while it is curing; don't take it into "sporty" sea conditions for 21 days. But the results seem very solid.

On a separate note, for my big Privilege cat side "windows" I use 795 to stick my large 10mm acrylic windows which glue to the sides of the catamaran hull without any screws needing to go through the acrylic. To hold vertical windows in place I make a wood "L" shaped pieces where the distance between the long leg of the "L" and the end of the short leg is the thickness of the lens (in my case 10mm plus the thickness of a chopstick pieces which I insert about 3/8" under the acrylic hold the window away from the hull to allow for sealant thickness while it dries. ). The "L" brackets are screwed into the hull just beyond the boarder of the window with the long side holding the acrylic and the short side as a standoff off the hull. I screw them into holes that I make in the area where the future and final 795 bead will cover the screw holes. After about a week, I remove the chopsticks and fill the shallow holes in with 795. After 2 weeks I remove the "L" support brackets and run a fresh, nice bead of 795 around the window. It is a bit of a pain, but it is the only way I have found to get nice results on large cat windows on vertical surfaces.

So is Sikaflex no good for this?

[Coltrek]

Not much sticks to Acrylic. I used Lexan and had two failures with lifeseal and then a Urethane that the fellow from the Glass shop told me would work. It didn't . Then I used the Sikaflex Kit using the 295 and the Primer, which finally worked. But the 295 doesn't age well. Now most people on our C&C list use a 3M VHB tape on the Acrylic, and 795 around the edges. Personally, I don't know why more people don't just use Safety Glass.

[Franziska]

Originally Posted by Coltrek

Not much sticks to Acrylic. I used Lexan and had two failures with lifeseal and then a Urethane that the fellow from the Glass shop told me would work. It didn't . Then I used the Sikaflex Kit using the 295 and the Primer, which finally worked. But the 295 doesn't age well. Now most people on our C&C list use a 3M VHB tape on the Acrylic, and 795 around the edges. Personally, I don't know why more people don't just use Safety Glass.

If you cover the bonding surface with black paint or tape on the exterior side of te window Sika lasts much longer. See their very thorough manual.

We painted about 4cm around our window edges with black PU paint to prevent UV getting onto the bonding area inside of our polycarbonate windows which are all glued with 295UV & primer.

[bbalan]

We rebedded every piece of thru-bolted deck hardware/hatches/etc. in 2014 with the butyl tape from Compass Marine.


Since then, we probably have 25,000 sea miles in many climes (Japan, AK, Mexico, French Polynesia and have had very few problems. I've had our 55 year-old trimaran for 34 years and used almost every product for bedding: Sika, 4200, 5200, etc. Bed It Butyl is really the only to go if the hatch is thru-bolted
Cheers,
Bruce

[GordMay]

Originally Posted by Dockhead

So is Sikaflex no good for this?

Which "Sikaflex"?
Sika offers a variety of “Sikaflex” elastic one-component adhesives and sealants, based on polyurethane (PU), or silane-terminated polymer (STP).

Ie:
Sikaflex®-221 ➥ https://industry.sika.com/en/home/ap...ODYzOS4wLjAuMA..

Sikaflex®-522 ➥ https://industry.sika.com/en/home/ap...ODUwMS4wLjAuMA..

Sikaflex®-591 ➥ https://industry.sika.com/en/home/ma...ODU4Mi4wLjAuMA..

[Franziska]

For gluing Acrylic or Polycarbonate use Sika 295i which is UV protected. Still you have to use the recommended primer on the glass and apply a UV covering on the outside (3-4cm wide should suffice.). Can be either a plastic self adhesive film, or 2K PU paint.

[Dockhead]

Originally Posted by GordMay

Which "Sikaflex"?
Sika offers a variety of “Sikaflex” elastic one-component adhesives and sealants, based on polyurethane (PU), or silane-terminated polymer (STP).

Ie:
Sikaflex®-221 ➥ https://industry.sika.com/en/home/ap...ODYzOS4wLjAuMA..

Sikaflex®-522 ➥ https://industry.sika.com/en/home/ap...ODUwMS4wLjAuMA..

Sikaflex®-591 ➥ https://industry.sika.com/en/home/ma...ODU4Mi4wLjAuMA..

You got me there. I believe it's Sikaflex 291 which I normally keep on board.

[bbalan]

For acrylic lenses into hatch frames, DOW CORNING 795 is what is often recommended. I've used it and it has lasted years.

B

[Franziska]

In case anyone uses Sika, here their technical reference.

If used in line with this it works very well. The UV protection outside and primer are very important though.

Be aware they use different materials for mineral glass and artificial glass (Polycarbonate, Plexi...).

[GordMay]

Originally Posted by Dockhead

You got me there. I believe it's Sikaflex 291 which I normally keep on board.

‘Sikaflex-291' is a multipurpose, 1-component, poly-urethane sealant, whereas ‘295' is often used for glazing applications.
291 ➥ https://can.sika.com/dam/dms/ca01/m/sikaflex-291.pdf
295 ➥ https://can.sika.com/dam/dms/ca01/l/sikaflex-295-uv.pdf