Leaking hatch

[iapetus]

Dear forum,

It's been raining cats, dogs and Saharian sand since the so-called spring season started, and I recently found a leak that developed around the starboard hatch.

Here is the offending hatch, dirty from "gabian" (vernacular name of these large, aggressive seagulls) mess and last night rain. The water accumulates under the arrow, that is, towards the the starboard side of the boat, due to the slight gradient of the deck.


Same thing, now opened. Some water can be seen where it accumulates


A closer look at the seal. Its seems broken, doesn't it?


Seen from the inside of the boat, arrow points to where the water is leaking. I noted that water was leaking inside the hatch, not around it.


Its port sibling has the same kind of somewhat broken seal, but doesn't leak at all. What could be the cause then ? The broken seal anyway, as shown on the third picture ? A bad mechanical adjustment that prevent the seal from playing its full role ?

Thanks!

 

[cobolt]

Not unusual to have a joint in the seal...it's much cheaper to manufacture this way than specific gaskets for each size hatch.

Normally there would be rubber/closed-cell foam inserts used as joining pieces, or it should be glued together...or both.

Hard to see from the photos if there are internal rubber/foam joiner pieces to keep the watertight integrity, or if simply the glue has failed. If that's the case, it can be re-glued using simple cyanoacrylate CA/superglue.

However, as the joint isn't where you're seeing the internal leak...it might be a red herring.

Other reason for leak could be a twisted frame, or simply that the seal has taken up a lot of compression-set over time. If you unscrew the handle, you might find some washers under there you can remove to increase the closing pressure when shut....I'm not that familiar with Nemo hatches but worth a shot.

 

[tico]

Altho marked 'Nemo' it looks VV similar to hatches made by Bomar.... replacement seal material is available and fairly simple to replace. Bomar ones were fitted to Fairline Targas.

 

[rafiki_]

I have exactly the same issue with my Nemo foredeck hatch. the seal isn't broken, it is the join from a continuous length, although it should have been better joined. I can see evidence of perishing on my seal. I have bought a replacement length of seal from http://www.sealsdirect.co.uk/shopping.asp?intDepartmentId=1#77

I have gone for the SR1707 as the groove in my hatch is 10mm wide. No idea if it is the right one, but cheap as chips, so nothing lost in ordering. The Nemo equiv is about €100 inc shipping.

 

[sorabain]

.
Hard to see from the photos if there are internal rubber/foam joiner pieces to keep the watertight integrity, or if simply the glue has failed. If that's the case, it can be re-glued using simple cyanoacrylate CA/superglue.

I was wondering whether "simple CA" would be appropriate as any rubber seal would need to be somewhat flexible to do its job, whereas whenever i've used CA (hobby use) it's formed an inflexible bond.

There do seem to be some special "flexy" CA products around for use with rubber seals though.

 

[oldgit]

You can purchase/get made a neat little shower cap arrangement with a drawstring or elastic which pops over the hatch to counter annoying dribblers.
More frequently found on older boat hatches where spares are non existant or damage may be caused during any attempt to dismantle hatch frame, which then makes matters worse.
Also useful for keeping out light if no light screen or screen U/S.

 

[iapetus]

Thanks for your replies !

Not unusual to have a joint in the seal...it's much cheaper to manufacture this way than specific gaskets for each size hatch.

Normally there would be rubber/closed-cell foam inserts used as joining pieces, or it should be glued together...or both.

Hard to see from the photos if there are internal rubber/foam joiner pieces to keep the watertight integrity, or if simply the glue has failed. If that's the case, it can be re-glued using simple cyanoacrylate CA/superglue.

However, as the joint isn't where you're seeing the internal leak...it might be a red herring.

Other reason for leak could be a twisted frame, or simply that the seal has taken up a lot of compression-set over time. If you unscrew the handle, you might find some washers under there you can remove to increase the closing pressure when shut....I'm not that familiar with Nemo hatches but worth a shot.

I can confirm there are no joiner pieces, only badly cut seal ends 2-3mm apart (it may be too much to re-glue, so is there any other material I could use to make it watertight again ? Silicone probably wouldn't hold ?)

A twisted frame maybe the culprit indeed. As for the seal, it was replaced 3 years ago before I bought the boat (or so says the invoice I got from the seller), surely its lifespan should be much longer...?

As for fine setting the closing pressure, good idea. I was afraid I would further damage the seal, but I'll give it a try.

Altho marked 'Nemo' it looks VV similar to hatches made by Bomar.... replacement seal material is available and fairly simple to replace. Bomar ones were fitted to Fairline Targas.

After a bit of googling, Nemo still seems to manufacture hatches (among other things), but, alas, not this one model.

The Nemo equiv is about €100 inc shipping.

Oah, that's highway robbery. Thanks for the site, much cheaper and as you say nothing much to lose.

 

[cobolt]

Simple CA is used on production line of most hatch makers, so should be fine.

I was wondering whether "simple CA" would be appropriate as any rubber seal would need to be somewhat flexible to do its job, whereas whenever i've used CA (hobby use) it's formed an inflexible bond.

There do seem to be some special "flexy" CA products around for use with rubber seals though.