Just trying to get a feel for the right size of a fillet. This is my first stich and glue boat and am definitely having some nervousness about doing it right. I filleted the inside of the boat today using a tongue depressor from the doc's office. It left me with a small fillet, about 1/2 inch in width, is that too small!?
In Sam Devlin's book - Devlin's boat building: How to build any boat the stich-and-glue way, he recommends that the thickness (depth) of the fillet at the joint be equal to 0.75 to 1.0 the thickness of the plywood. The runout (distance of the fillet from joint to edge) should be 1.5 x 2.0 the thickness of the plywood. If you are attaching a 1/2" bottom to 1/4" sides the thickness should be based on the thicker plywood panel. Fillet thickness would be 3/8" to 1/2" and runout (each side) 3/4" to 1". These will be covered with glass tape.
If you are building stitch-and-glue also check out Montana River Boats, Devlin Boat Building, Chesapeak (sic) Light Craft and Glen-L for thoughts on this and other building suggestions.