A new hatch:
I had the same problem with my 78 H-27. The hatch hinge broke and the cover went South (it sank). I called Bomar now owned by Pommenette and they were not really helpful. I purchased a 21" square hatch from Bomar through West Marien and planned to enlarg the opening. If you want to know the exact size e mail me at Nelsonhow@aol.com. The job went like this: I removed the old hatch trim and cleaned the area of caulk with a scraper and paint thinner. I then placed the new hatch in the existing opening. The rear fit like a glove but since the opening was trapizoidal the front did not fit. I expected this. So.. I took the new hatch out and placed it on a scrap of 1/4" plywood about 28" square. I traced the the new hatch size leaving about 1/8" additional for a router guide. A carpenters pencil gives you about the right additional space. Since the new hatch has a 3/4" trim ring you have about 1/4" inch to play with. But make the templace as carefully as possible. I secured the template to the top of the deck with 2 sided carpet tape so that the rear of the templace was 1/8" outside of the rear of the deck cut out. The rear of the opening did not need to be enlarged. Then I cut out the front and forward sides of the opening. The sides were just fiberglass and gelcoat. No structural cutting. In the front I remove a very small amount form the internal beam of the deck less than a 1/2" from the corner. So I don't think the strength is affected. I cut the opening with a 3" x1/4" carbide tipped router bit. I cut about 2/1/2" deep, enough to allow the dogs on the hatch to clear the headliner. When I was done I removed the template dry fit the hatch and relaized that I needed to go a litter deeper in the front to accomidate the hatch dogs. I cut the addition from the font without the templte. After I was done cutting I used a dremel sander and wood block to clean and sand the areas I cut out. Then I used several coats of marine paint to seal the exposed beam edge and fiberglass. Since none of the area will be exposed to the outside I elected not to use gelcoat or resin. In fact 99% of the area is covered by the interior of the hatch trim. I used 5200 caulk to bed the hatch and new stainless screws. After this was done I use more 5200 to fill the interior gaps arount the trim. I'm not much of a craftsman but my crew who are, give me a 98%. Next time maybe I'll get 100%. By the way the hatch cost $230,router but $20 (ouch but it was carbide, don't skimp here) screws $3, Caulk $8, Paint $4 (4oz of marine white touch up). It beat the cost of a new trapozoidal hatch with was $600 and would still require me to cut the deck. Total time not counting drying time about 4 hours. If you have a rounter and are a little fearless it not a big job. It was easier than making new hatch boards out of Oak.
