I'm awaiting a reply from pompanette; meanwhile, what is the thickness of the lexan for the hatches? 3/8"? I'm refurbishing the hatches and can find all the other info (thanks Ed) and parts, just not sure about thickness.
I rebuilt mine last year. The lenses are 3/16" thick Lexan. Lexan lenses are
much thinner than Acrylic ones. That's why they have the reinforcing bars underneath them. Although the Lexan is very strong, it will flex when stepped upon if unsupported. This flexing would cause foreshortening of the lens width and separate the seal at the edge, causing them to leak.
A 3/16" thick lens stands just slightly proud of the lip on the hatch. This prevents standing water from accumulating on the hatch.
When I ordered my lexan from Mcmaster-Carr, I paid extra and got the UV/Scratch-resistant coating, as Lexan has a tendency to fog with UV exposure. I then used the old lenses to create a template out of 3/4" MDF (Medium-Density Fiberboard), stuck it onto the Lexan with turner's tape, and used a router with a sharp template bit to cut out the lenses. For lens bedding, I used Dow Corning 795 which is
excellent for this application.
As for the hatch frames themselves, after disassembly, I took them to a custom auto paint shop and had them powder coated. I expect this will outlast the boat. If you go for powder coating, be sure to tell the shop to bake them before priming to get them to outgas. If this is not done, it will produce bubbles in the finished coating, as salt water corrosion causes the frames to become quite porous at the microscopic level.
