Used the template to cut ribs for the hatch out of lightweight half inch plywood.
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It seems a little too lightweight. I followed the instructions on the wikibooks that suggested making ribs with one straight edge to prevent springback. If the hatch starts to bow, or doesn't seen solid enough, I'll beef it up with some additional wood. Need to go shopping for some lightweight 2x2s to finish the frame of the hatch.
I have ordered some sealant (epoxy resin) from jamestown distributors for the exposed wood, and a plastic piano hinge from monroe engineering. Need to pick up some aluminum strips for the screws that are going to go into the hatch. I also need to go pick up rest of the exterior finishing materials.
The original owner (Mike) left a hole in the front near the top.
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I think he may have been planning to run an air conditioner duct or perhaps place vents there. I'll have to ask him. I was going to just insulate it and seal it up with more thin plywood inside and out, but now I'm thinking, "Skylight!" Trouble is finding a little window or something that will fit well there, including following the curve, and making it watertight. I may just seal it up to keep the number of seams to a minimum. There's a nice radiused cut there, which would need to be trimmed down to get the next piece on there.
More updates to come.