Thoughts on Leaking Hatch ?

[twistedtree]

I've got a forward hatch that's leaking pretty much any time it rains. It's made by Man Ship and is a 24"x24" smoked glass hatch with stainless frame. I've looked it over and can't spot anything obvious. With rain coming straight down, it would appear there are two possible entry points. One is the seal where the glass fits into the hatch frame, and the other is the bedding where the frame attaches to the deck.

I know there is little one can do to help diagnose such a problem over the internet, but I'd welcome any thoughts on two fronts:

1) Are there any common failure points that I should focus on?

2) Are there any good techniques for locating/tracing the entry point?

Thanks,

Peter

[neilpride]

You right, frame bedding with the deck and lexan caulk with the frame, i sugest to pull the whole hatch, clean the old compound from deck and frame, you can use butyl tape for the deck and frame and caulking compound for the lexan , be sure the caulk for the lexan have Uv protection and be sure all is neat clean , no traces of old caulking, dont press the lexan to hard in the frame and dont tight screws if there is any to tight in the lexan.. Good luck..

[sy_gilana]

Div ide and conquer!
Tape the seams where the lexan fits into the frame, wait for rain, leaks...its not the lexan, no leaks, it is.

Get a plastic bag, ziplock type, cut into strips of say 2" x 4" lay them over the sealing edge, close hatch, then pull them out. Those that come out easily could indicate a warped frame.

Finally tape the seams to the deck, covering the screw holes, wait for rain...

and really finally, put a bucket under it

[twistedtree]

Originally Posted by neilpride

you can use butyl tape for the deck and frame and caulking compound for the lexan

Thanks. Just curious - why butyl tape and not 4200 or equivalent?

There are two "frames". The bottom one that attaches to the deck, and the top frame that houses the glass and is hinged to the bottom frame.

The glass appears to set into the top frame with a seal, not calking, but I can't say for sure.

[twistedtree]

Originally Posted by sy_gilana

Div ide and conquer!
Tape the seams where the lexan fits into the frame, wait for rain, leaks...its not the lexan, no leaks, it is.

Get a plastic bag, ziplock type, cut into strips of say 2" x 4" lay them over the sealing edge, close hatch, then pull them out. Those that come out easily could indicate a warped frame.

Finally tape the seams to the deck, covering the screw holes, wait for rain...

and really finally, put a bucket under it

Thanks - that's just the sort of technique I was looking for.

[barnakiel]

I would start with the seal. One man with the hose (outside! ;-) one with a watchful eye inside. Any water thru the seal tends to drop from the inner rim of the hatch. If in doubt, replace the seal.

Water coming from under the hatch tends to mess the interior wood or whatever you have there as a liner round the offending hatch. Then you will have to gently remove the hatch, clean the surfaces and re-attach the hatch onto new sealant. If so, do NOT over-tighten the holding bolts/screws - or else you will bend the hatch frame and it will leak again.

b.

[ShipShape]

Thank Bill Seifert for this idea: tape a thread across opposite corners so they cross in the middle of the hatch in an X. If they don't touch then your hatch (or its mounting surface) is warped. You may have to switch which thread is on top to find out. If it is warped then use the largest possible really squishy foam for the gasket.

One of my hatch leaks was through the itty bitty gap where the two gasket ends joined.

Thanks for your idea twistedtree ... seems the more I learn about boats the more practice I get going "duhhhhh"

Butyl tape rocks - for more info see mainsail's tutorial Re-Bedding Deck Hardware Photo Gallery by Compass Marine at pbase.com

[Cheechako]

Yeah, just remove it and reseal the lexan and rebed it when you screw it back on. Look for rot in the surrounding deck core once it's off... It's a pretty big job... a lot of scraping etc to clean things up good.

[Captmorpheus]

Tony is the expert and he is willing to share his info. There is much info on which sealants to use and how to prep on his site. His hatch repair services seem expensive as do his material prices but his information is free and free is for me. I just pulled my hatch and am in the middle of a rebuild. Good luck.

Tony's Blog | Select Plastics, LLC - Connecticut's Best Custom Fabricated Plastics and Marine Hatch Repair