: If you do not yet have it, get a copy of Thomas Hill's book,
: "Ultralight Boatbuilding". Amazon has it on sale right
: now for under $14, and I think you would find it very worth
: while.

:
: http://www.amazon.com/Ultralight-Boatbuilding-Thomas-Hill/dp/0071567038/ref=sr_1_1?ie=UTF8&s=books&qid=1301387084&sr=1-1

: Hill does build on forms, and he does so because they define the
: size of the plywood strakes he cuts. It is simple to just set a
: piece in place and trace the edge, then cut it and it fits. The
: forms also serve as a guide for his router (or you could use a
: plane). He mounts the tool to a short, straight piece of wood,
: and it follows over the building form, using the form as a full
: length jig for perfectly beveling the glue joint between each
: plank or strake.

: Using 1/8th inch plywood, his overlaps are 1/4" thick (the
: thickness of both layers of plywood), and about 3/4" wide,
: or maybe a bit wider. If you were to build a SOF design with
: 1/8th inch thick ribs placed continuously side by side, with no
: spacing between them, and then cover that with chines which were
: 1/4" x 3/4", running the full length of the boat, and
: about 4" apart, then you would get some idea of the design
: strength of this type of construction. It is strong with using
: fiberglass, although Hill does suggest using a football shaped
: piece of fiberglass as a grunge-absorbing skid plate on the
: bottom of the hull.

: If you don't want a lapstrake look, then just cut the parts to butt
: against each other instead of overlap. here you can do a bevel
: edge, or you cna make a seam like S&G and fill the inside
: with a fillet of fiberglass to waterproof it and strengthen it.

: I think you would work faster using forms instead of those flexible
: ribs. Cost is not an issue. Forms can be made from scrap
: cardboard, or cheap particle board. Anything which does not flex
: like a rib is going to do will help keep your design intact.
: Many designs only need three to five forms to define the basic
: shape. A cross seciton of the middle of the boat, and one near
: each end to increase the capacity of the boat. Bend your full
: length strips around these and secure them to the ends. You
: would have five points of solid contact for each strip. Put on a
: patch 3 strips wide along the keel. do the same along each
: gunwale. That is 9 strips you can put on the first day. and you
: can do more. Jump about inches from the gunwale and lay on 3
: more strips in the middle of each sidewall. That is 15 strips
: the first day. Once you got a bunch of strips on the forms you
: could bend ribs into the developing shape and glue them to the
: strips. You can cut 2 1/4" to 3" strips of plywood and
: use those in these areas instead of cedar strips. These areas
: are fairly flat and the wide material goes on pretty well.

: If you want to save time on fitting individual strips, lay out the
: rest of the strips on the bottom perfectly paralell with the
: three you put along the keel line. let the ends overhang. You
: may not need to do much planing ot get thses to fit tight, and
: you may be able to do 5 to 10 strips to each side at one time.
: Once the glue has set up, draw a curved line about an inch
: inside where the strips go araound the bilge, and cut along that
: line to remove all the overhanging ends of your bottom strips.
: Now you just need to trim and fit the strips which go around the
: bilge. Those take some time anyhow.

: Just some ideas for you to consider playing with on your next boat.

: Happy building

: PGJ

He doesn't want to use fiberglass, have to have ribs to hold the planks together.

Bill H.