Lewmar Super hatch update and question

Sep 22, 2017
97
Capital Yachts Newport 28 Burbank, WA
Well, I finished installing the new lens in the Lewmar Super hatch on our N28. I replaced the hatch to frame seal too. I ended up using 1/2" thick cell cast acrylic to make the new lens. The original used a thin seal of butyl between the lens and frame, then the gap between the inside edge of the lens and frame was filled with some sort of sealant. All of which had failed.
The original lens was 10mm thick. I could not get a piece of 10mm, so I went with 1/2" cell cast acrylic.
Instead of the thin butyl between the lens and frame, I used Dow 995 structural adhesive, and filled the edge gap with Dow 795. Both are designed to attach and seal window glazings to the frames. I also sanded the area of the lens that sits in the frame for better adhesion. Its not perfect, but all in all it turned out fine. Hopefully the Dow products will keep it all sealed up.

I am getting ready to re-install the new lens/frame back onto the boat. I have one more question to resolve before I do. The hinges that attach the hatch to the lower frame is made of two aluminum flat arms. These arms bolt to the new acrylic lens. When I removed mine, there was no seal of any sort between the lens and the hinge arms. For those of you that have rebuilt their hatches, what type of seal did you use between the hinges and the lens? I am considering making a couple of flat gaskets out of either neoprene or EDPM rubber to fit between the hinge arms and the acrylic. I will probably used some butyl around the screw threads to seal the screws to the T nuts. That should make a nice long lasting water tight seal. Any comments on your experiences would be greatly appreciated.
 

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Aug 1, 2011
3,458
Catalina 270 Wabamun - on the orange ball
Order up a roll of Maine Sail butyl. To say that you will not be disappointed is quite possibly a serious understatement.
 
Sep 22, 2017
97
Capital Yachts Newport 28 Burbank, WA
Meriachee,
I have a roll of Mainsails Butyl. I have chosen not to use it for the primary seal between the acrylic and hinges. I do plan on using it around the screws that attach the hinges to the acrylic. I am trying to figure out what to use between the hinge and the acrylic to cushion and protect the acrylic during use, and expansion/contraction due to heating/cooling. Acrylic expands quite a bit due to temperature. At this point, I am going to use a piece of EDPM between the hinge and acrylic, and butyl around the screws to seal them. Hopefully someone who had done this job will weigh in and let me know what they did, and how it turned out.