I'm going to be starting my hatch. I have a pretty good idea about how to do it, but am concerned about the 1/8 th ply 'springing' the ribs out of shape causing the hatch to fit poorly.
I plan on using Steve Fredericks as a guide, but will not have an interior skin, so the ribs will be exposed..
First, is 1/8" ply thick enough for a hatch, or do I need 1/4".? I'd like to use 1/8th is possible for lightness.... I'll probably insert blocks between the ribs for torsional strength.
How many ribs and what dimension (x-section) is needed for strength?
What material is best? I'm thinking of cutting them out of 1x6 pine and gluing sections together to get the curve....
Right now, I'm guessing the hatch will be less than 4 feet from top to bottom, and I'm going to make the curve as slight as possible to reduce springing mentioned above.
Any do's and don'ts are appreciated......