Should engine deck hatches have rubber seals?
#1

All I can see in my searches most engine hatches don't have seals, there is a raised lip around the hatch opening and an overlap of the hatch lid, and there is room for a seal. The raised edge around the hatch forms a trough with its own drain, so it seems logical if you wanted to keep water and dirt out of the engine compartment that you'd want a seal. Should they have seals, I was thinking of a good quality seal in a track to avoid adhesives?
Also I think we need something like a seal maybe a rubber pad to close the engine hatch doors against, since our hatch doors close a little lower than the deck and it stresses the hinges to break and/or works the screws loose.
Also the hinges just go through the fiberglass and stick out on the inside of the hatch, should I put a block of plastic/starboard under each hinge for those screws to screw into? Or is it designed that way to be just screws so if it does rip our it won't do much damage to the hatch?


Also I think we need something like a seal maybe a rubber pad to close the engine hatch doors against, since our hatch doors close a little lower than the deck and it stresses the hinges to break and/or works the screws loose.
Also the hinges just go through the fiberglass and stick out on the inside of the hatch, should I put a block of plastic/starboard under each hinge for those screws to screw into? Or is it designed that way to be just screws so if it does rip our it won't do much damage to the hatch?


#2

Bump, any info is appreciated. Should our engine hatches have a seal to help keep dirt and water out? And should our hatch screws just stick out like that on the inside? Thank you.
#3
Admirals Club 


The system pictured does a far better job of preventing water egress into the engine compartment. The only places I have seen sealed engine hatches is on the inside a closed cabin or pilot house where water is not usually an issue. The screws are fine and don't appear to be a safety hazard where they are located.
#4

The bottom surface on my movable and on my manually removable engine compartment hatches all have large seals, probably O shaped when new, probably 1½" diameter and 1/8" thick, adhesive bonded to the hatch. Mine look like those shown in the image.
The screws are probably fine if they are not contacting other parts. The points could be cut off w/ a Dremel if desired. Don't cut flush, leaving several threads extending for strength.
The screws are probably fine if they are not contacting other parts. The points could be cut off w/ a Dremel if desired. Don't cut flush, leaving several threads extending for strength.
#5
Senior Member

Do not install seals. They can interfere with drain-routes and reduce engine compartment ventilation.
When I encountered screws like that I built-up an epoxy “bump” around / encapsulating them to prevent them snagging anything while adding strength to their holding power. A hot-glue-gun treatment might insulate those sharp points similarly but won’t add strength.
A block of wood would (pun) do the same, woodn’t it?
(Except that would require loosening then re-tightening the screws and I don’t like that.)
Marine-Tex, etc
When I encountered screws like that I built-up an epoxy “bump” around / encapsulating them to prevent them snagging anything while adding strength to their holding power. A hot-glue-gun treatment might insulate those sharp points similarly but won’t add strength.
A block of wood would (pun) do the same, woodn’t it?

(Except that would require loosening then re-tightening the screws and I don’t like that.)
Marine-Tex, etc
#6
Senior Member

If you put a seal on the hatch, rain water could build up and flood other areas instead of draining out properly. We have been getting a lot of rain here in SWFL and my engine compartment hatch does its job about 99%. The other 1% just gets flushed out with the bilge pump.
#7

Thank you all for the replies, good advice on the screws. It is an older 30ft express cruiser with two I/O VP 5.0s, I am on the West coast but I read the stories on here where a wave coming over the transom can swamp a boat and I wanted to minimize water getting into the engine compartment if that could ever happen here. If hatches were sealed most water would go out back door and down hatch gutter drains, but maybe it isn't a concern.
As I mentioned though, another reason for the seal would be to raise the hatch to deck level. The hatch lids sit lower than the deck when closed and it stresses out the hinges to the point where they break or the screws get loose. If I put the seal on top of the raised edge of the gutter it shouldn't impact gutter flow to the drain. If not a seal I think I need some bumpers to raise the hatch lid to deck level, rather than putting a shim under the hinge plate.

Here is an article I found recently on adding seals:
https://www.boatingmag.com/how-to/ho...d-hatch-seals/
As I mentioned though, another reason for the seal would be to raise the hatch to deck level. The hatch lids sit lower than the deck when closed and it stresses out the hinges to the point where they break or the screws get loose. If I put the seal on top of the raised edge of the gutter it shouldn't impact gutter flow to the drain. If not a seal I think I need some bumpers to raise the hatch lid to deck level, rather than putting a shim under the hinge plate.

Here is an article I found recently on adding seals:
https://www.boatingmag.com/how-to/ho...d-hatch-seals/
#8
Senior Member

Couple of things before you can say seal or no seal.
Does the engine hatch have a positive latch in the down position? If it does then the seal needs to be flat enough not to interfere with the latch "reach".
If it doesn't have a latch, are there any spacers that hold it in a certain location to relieve the screws and hinge of the load? On several engine hatches I've had the hatch closes to a certain spot that is supported by a plastic shim. This keeps it from rattling and allows the hinges to stay in alignment.
That looks like a decent drain in the corner, does that go overboard or into the bilge? If it goes into bilge a seal isn't going to reduce your rain or dirt load at all.
Does the engine hatch have a positive latch in the down position? If it does then the seal needs to be flat enough not to interfere with the latch "reach".
If it doesn't have a latch, are there any spacers that hold it in a certain location to relieve the screws and hinge of the load? On several engine hatches I've had the hatch closes to a certain spot that is supported by a plastic shim. This keeps it from rattling and allows the hinges to stay in alignment.
That looks like a decent drain in the corner, does that go overboard or into the bilge? If it goes into bilge a seal isn't going to reduce your rain or dirt load at all.
#9
Admirals Club 


Gemlux makes offset hinges that would fix that problem or you could cut out a piece of HDP and make a shim under the short hinge.
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#11
Senior Member


Re: those protruding screws- Someday someone may well rip their arm or hand open on them . I'd replace with appropriate-head SS machine screws, small washer & thin nut with thread lock and grind excess length flush.
As they say, " Better safe than swearing."
As they say, " Better safe than swearing."
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#12

Couple of things before you can say seal or no seal.
Does the engine hatch have a positive latch in the down position? If it does then the seal needs to be flat enough not to interfere with the latch "reach".
If it doesn't have a latch, are there any spacers that hold it in a certain location to relieve the screws and hinge of the load? On several engine hatches I've had the hatch closes to a certain spot that is supported by a plastic shim. This keeps it from rattling and allows the hinges to stay in alignment.
That looks like a decent drain in the corner, does that go overboard or into the bilge? If it goes into bilge a seal isn't going to reduce your rain or dirt load at all.
Does the engine hatch have a positive latch in the down position? If it does then the seal needs to be flat enough not to interfere with the latch "reach".
If it doesn't have a latch, are there any spacers that hold it in a certain location to relieve the screws and hinge of the load? On several engine hatches I've had the hatch closes to a certain spot that is supported by a plastic shim. This keeps it from rattling and allows the hinges to stay in alignment.
That looks like a decent drain in the corner, does that go overboard or into the bilge? If it goes into bilge a seal isn't going to reduce your rain or dirt load at all.
No latch, just the weight of the large hatch holds it closed, and a SpingLift gas strut holds it open.
Yes, the drain goes overboard, exits under the swim step, one on each side for each hatch. Center hatch has no drain, but gutters connect for all 3 hatch lids.
From my reading, SeaRay had a seal there on some models. I own a Monterey which seems similar.
I have "blower" vents on both aft gunwales so I don't think the unsealed hatches are needed for air for the engines and if they are then I'd better keep the deck and hatch gutters cleaner than I am.
#13
Admirals Club

That is pretty much the same system I have on my boat and it works just fine..
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