Need to reset the plexiglass in forward hatch

[Nick in Manitou]

(I originally posted this a couple hours ago in the "For Sale" section not realizing that I had not returned to the "Tech Talk" section where I intended to post it.)

Our 1984 53' ED has a leak between the plexiglass and the frame of the hatch over the v-berth.

I have gotten two very different opinions already from knowledgeable friends about how to proceed to reseal it.

One said to use silicone - allowing a small continuous bead to set up for the plexi to sit on, then one it has set up apply more silicone and bed the plexi in that on top of the small bead that has already set up. The theory he says is that with the frame and the plexiglass expanding and contracting at different rates, the cured silicone bead under the plexi will remain intact whereas if the plexi is bedded in silicone in just one step, the different rates of expansion and contraction will cause the silicone to loose its adherence to one of the surfaces allowing for leaks to start again. - It sounds sensible to me!

The other instruction I was given was to find a sealant designed for the purpose and that it would work fine.

I don't know what material the frame of the hatch is made of, but the unit is right heavy!

Any experience with this issue?

Thanks!

Attached Images

[SKYCHENEY]

The plexi expands and contracts quite a bit with temperature variation. This breaks the caulk. That is why Hatteras did not use plexi and instead went with fiberglass. You can reseal, but it will likely always be an issue over time if you don't rough up the plexi first so the caulk sticks and use something that will flex and move.

I talked with Tom Slane when I was considering doing this and he told me not to do it because it would eventually leak.

[Scott Mather]

I converted one of the old yellow fiberglass hatches to this system years ago.
Cut out old yellow fiberglass, bolted in a plexiglass window just like above.
Used basic silicone for seal, never leaked in 15 years.
Main difference is using 3 times as many bolts to secure.

[jim rosenthal]

What you have there, I think, is an original hatch which has been modified with the plexi window in it. Your best bet, if you can do it, would be to find an original hatch and have it repainted to match your boat. Then throw away the present hatch. These hatches were one piece for a good reason; they don't leak. Mine is 48 years old and does not leak.

[Leland]

Okay...my two cents. I NEVER use silicone caulk anywhere on a boat... for a variety of reasons. My personal choice is one of several urethane caulks. I have found them to bond better and be easier to deal with later. And they are paintable. I have a mess of silicone caulk boogers to deal with that the PO used to seal anywhere and everywhere he thought there was a leak. Also, never bondo…

bob

[MadHatter53]

My bow hatch has a leak in a corner where the glass sits in the frame. It looks like it was repaired but not that well. I plan on re bedding this year and not sure what to use.

[SKYCHENEY]

My bow hatch has a leak in a corner where the glass sits in the frame. It looks like it was repaired but not that well. I plan on re bedding this year and not sure what to use.

As Jim stated, the original hatches are one piece. If you have glass in it then it was something someone did to modify later.

[rtrafford]

Silicone is terrific for UV, but has been stated the plexi is going to move quite a bit with sun. Consider using Sikaflex 295 UV instead of silicone, and be prepared to revisit this hatch annually for maintenance. And, yes, sand the edge of the plexiglass that will receive sealant prior to installation. Might also consider Lexan if you're going to sea considering the location.

[jim rosenthal]

Nick, here's what I did with mine- I took the original hatch and sanded it down, and painted it with AwlGrip to match the decks, etc. From the outside, the hatch is a uniform color, but from underneath a surprising amount of light does come through. It looks fine and has held up nicely. As I recall (it's been a while) when I got the boat, the center section was not painted and the exposed laminate was yellow- didn't look great. Painting it solved that problem.

I don't know if Sam's have hatches. If they do, it would be the way to go. If you PM the dimensions of the hatch cover, I'll keep an eye out for one. There's got to be one out there someplace.

[Nick in Manitou]

Jim, thanks for the offer to keep an eye open for a replacement hatch cover for me.

The fixed (male) part that sticks up from the deck is about 28" fore to aft - side to side it measures about 29".
The hatch cover has a thick rubber gasket that rests on the top of the fixed portion when the hatch is closed. The edges of the hatch cover hang down about 1 1/4" from the underside of the hatch cover, overlapping the stationary portion of the hatch.

Given the rather long list of things I want to tackle on the boat at this time and the fact that I use the v-berth as my "office" and really enjoy having as much light as the hatch currently gives me, I think that I will first make an attempt at resealing the plexiglass and see how long that lasts.

Nick