: . . . I was going to rib at each form and in between. Was I aiming for over
: kill? Will your idea be sufficient? Is there a good way to interpolate new
: forms in between the existing ones? . . .

George Putz's ideas for making the floor boards in his Walrus design can be extended to perhaps solve your problem with designing intermediate ribs.

Start with the rib designs you now have, and either mount them to your stringers, or use temporary stringers of 1/2 inch pvc pipe. You may need a strongback, or a long flat working surface to hold this in alignment, but get at least 4 ribs set in place, and spaced the proper distance from each other. When you bend the stringers over these 4 ribs you will have a framework from which to measure the size and shape of any intermediate ribs.

Let's say your plans show the ribs are spaced initially at 16 inches apart, and you want to have ribs at 8 inch intervals. Set up the 4 closest to the bow, and you'll have the front 48 inches of the boat assembled. Get that part aligned. Add more ribs if you must. Mount the stringers, or the 1/2 inch PVC pipe. This can be a temporary mounting using string, cable ties, twisted wire, or whatever.

It is now just a matter of getting a piece of cardboard, spacing it halfway between each set of ribs, and marking on it the shape defined by the stringers.

A simple way to do this is to use a cardboard piece that is smaller than the size of the finished rib, roughly center it between the stringers, and tape additional strips of cardboard onto it, like fingers, touching the stringers.

If you have 7 stringers your cardboard template will have seven cardboard strips attached to it. Remove this template and lay it on a sheet of paper. Mark the paper at the seven points where the "fingers" touched the stringers. Connect these seven dots and you have the approximate shape of your intermediate rib. Of course your drawing will have straight lines, and the steamed rib will have curves, so you may want to use a thin piece of woodstrip, to connect these dots.

Another suggestion. Take the cardboard pattern and place it on a piece of 3/4 inch plywood instead of paper. Put a 4 penny finishing nail at each of the 7 spots where the "fingers" of the template touched the stringers. These nails serve as "stops". Make a few very thin strips of some very flexible wood (1/16th inch should be fine). Place one strip on the plywood, inside the pattern of nails, and pull it into the shape of the necessary rib. Where the ends of the strip overlap you can secure them together with a drop of hot glue, or use wood workers glue and clamp them until the glue dries. Later you can reinforce the outside of this ring by driving additional nails into the plywood, or by adding additional layers of wood to the outside, and gluing and clamping them in place.

You will now have a ring that can serve as the outside form for any bent wood ribs you construct. Just steam the rib material, and after removing it from the steamer bend it so it fits into this form. Gentle clamping may be needed to make the rib conform to the proper shape, After it cools it should spring back more than enough to makeup for the thickness of the ring. Just set the rib inside the nails and they will hold it in place as you trim the ends of the bent wood rib and lash or glue them together.

You can make several jigs like this on a single sheet of plywood by simply making them in concentric fashion. The smallest rib inside the shape for the next smallest, and so on, with every rib nested inside the outline of the largest rib.

Hope this helps.

Paul G. Jacobson