I’ve seen a lot of pictures where the galley door spars/ribs are cut from plywood and the results look less than exciting. Initially I chose the 48″ radius to maximize strength, space and simplicity. Later when I started planning out the galley door I was even happier that I decided to go with a radius rather than a changing curve because I can make a jig easily to laminate thin pieces of wood into the curve of the trailer. The door will also fit perfectly into the tracks on the side because all the pieces will be made from the same jig. It suddenly occurred to me that if the curve was not a consistent radius making ribs this way would be a nightmare. This will give me a great fit (less chance of leaking), a classic profile and a clean and professional look.
The first step is to build a giant compass to draw the concentric arcs. The ribs will have an outside radius of 48 inches and inside radius of 46.5 inches. I also wanted to draw out where laminations stop or change. The galley door ribs are simple but the side tracks are a little different. This jig provides all the information on the different heights of the different dimensions of each piece. Drawing it out with a giant adjustable compass I made in about 20 minutes was a snap. A compressible slot with a guide for a regular pencil clamps on the pencil with a 1/4 inch carriage bolt. The end that holds the pencil is glued to the side guides but is dry fit and clamped on the longer shaft and screwed into the MDF. Simply loosen the clamp, adjust to a new concentric radius and tighten and you end up with accurately drawn guide lines for building the jig.
With the lines drawn I added blocks that I will clamp the laminations against. I believe that there won’t be any springback but these techniques are partly experimental. I can also use this jig later if I want to make cabinet doors in the lower galley that conform to the curve of the door.
The last thing I need to do tomorrow before starting the lamination process is to cut out the jig so that I can move it around and put aside while I work on other things. Pretty hot out in the garage so this will be a baby step summer.