1984 C36 Hatch Leaks

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Greetings,

We have 3 Bomar hatches overhead - one large on in the center, one smaller one in the head, and a matching small one opposite of it to starboard.

They leak. The large one seemed to be leaking past the frame, so we removed it and re-bedded it with butyl tape, but it still leaks. It's a mystery to use how the water is getting in.

Any hints?

Thanks,

jv
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
It's a 1984 Catalina 36. Folks who know this hatch and this boat might know the answer. Pics aren't going to help.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
If you think you sealed the two Bomars well by removing, cleaning and a good application of butyl. Then the water is coming in elsewhere and only exiting into the cabin at the hatches. I would look at the mast collar.

Les
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
If you think you sealed the two Bomars well by removing, cleaning and a good application of butyl. Then the water is coming in elsewhere and only exiting into the cabin at the hatches. I would look at the mast collar.

Les
Thanks Les. We only did the main hatch so far. I think I would see the water on the overhead if it was coming from the mast boot. The core was dry when we removed the hatch.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
I would think a dry core would imply the water is coming in either the top or top gasket. Can you tell where the water is dripping from??

Les
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
Also water from the mast Collar can run down in the space between liner and deck
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
I would think a dry core would imply the water is coming in either the top or top gasket. Can you tell where the water is dripping from??

Les
It really looks like it's dripping from the corner where the hatch frame and deck meet. A bit of a mystery,
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Also water from the mast Collar can run down in the space between liner and deck
I must say that I don't understand this comment. By "the liner," do you mean the overhead? That's fiberglass, bonded to the plywood core, as far as I know.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
It may not be as solid as you would think. Even if there is no water intrusion/rot / delamination.

Les
 
Aug 21, 2015
5
Catalina 34 MI
Hi there - I have a C34 ( 1986) and had the same problem. Leak in the front corner right of the bowmar hatch frame. Below decks is a teak frame for a bug screen. I took the hatch out, cleaned it and used Dow corning instead of the butyl tape. The stuff is usually used for the fixed portlights, had a cartridge left over from re-doing all fixed port lights a few years back. It's black, so need to tape the deck around the hatch perimeter. Put enough of it with a caulking gun onthe underside of the frame so it squeezes out inside and on the perimeter of the hatch frame. Do not tighten it down right away. Let it cure, 24 h, then tighten it down.
Worked for me.
Guenter
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Thanks, Guenter. Based on how we sealed it with the butyl tape, I can't imagine how water is getting in; but perhaps we'll remove it and re-do it. We have the leak in the same place, and have the same wood-framed bug screen.
 
Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
jviss, if you are sure of your bedding, then it's not that. I re-bedded my hatch a few years ago and wrote a Mainsheet tech article about it, used butyl tape. Last year I started to get persistent drips from the forward port corner. I thought for sure I'd have to yank it out and start all over again. Being the sailor I am, I put a pot on the cabin sole to catch the drips until "I could get to it!" :) Once I did, I inspected the leak more carefully. I determined that it appeared that the leak was coming NOT from the frame, but from the glazing to the frame. A friend of mine in Chicago with a C34 took his off and had the glazing redone by an auto parts store. Instead of that I waited for a sunny day and applied Captain Tolley's Creeping Crack Cure around the leaking area.

Problem solved.

Good luck. Mine is a 1986 Bomar hatch, too.