RE: Four Star 60 Turtle Deck Sheeting
When I built my cowl, I used 3/8" sheet to make the "box" and then reinforced the joints with triangle stock after I pulled the engine and engine mount. I also used a lite-ply ring that I had left over from my high powered rocket days that was the exact size to match the spinner.
To sheet the turtle deck, added some balsa strips in between the formers to give the 1/16" sheeting something to attach to and also trimmed the base of each former enough to sheeting to fit flush with the fuse sides. I then took a piece of poster board and cut it to the exact fit for the turtle deck and then traced the shape onto the two sheets of 1/16" that I had previously glued together. Once I cut out the sheet, just sprayed it with windex w/amonia and formed it to shape and held it with rubber bands until it dried. Then glued it in place