: How strong does it ned to be? the water pressure compressing the
: wood is under 1/2 p.s.i. A sheet of paper can hold withstand a
: dozen times that. Cardboard and thin wood are hundreds of times
: more resistant to pressure.

: True, but he is overlapping two strips. Each strip has it's own
: grain pattern, and the combination seems to let one layer of
: strips reinforce the adjoining layer is made from veneers. Some
: are cut like thin boards. Others are cut in a rotary manner, and
: the resulting grain pattern is nothing like what you might see
: in a cut board.

: Use enough glue and you can make a "board" from shredded
: wood fibers or even sawdust. Not sure what grain would have to
: do with something like that--but particle board and OSB, in the
: proper thicknesses, are structurally sound. Epoxy over a strip
: turns it into a combination of wood and plastic. The resin which
: soaks into the wood greatly strengthens it. To some extent
: varnish and polyurethane coatings also add a small amount of
: structural change to the wood.

: "added thickness in certain places" might be more
: accurate.

: With thin strips the direction of the grain has more to do with its
: ability to bend, or resist bending. A bow (archery) has the
: grain running from end to end and when you pull back the string
: it flexes, first absorbing great pressure in compression (on the
: inside of the bow) and tension on the outside of the bow, then
: releasing that when the bow string is released. In a boat the
: load is mostly carried by the gunwales, and the ribs transmit
: this load along the sides and up to the gunwales. They could do
: this with any orientation of the grain. One way might be
: slightly better than another, but the size of ribs can be very
: slight, and they will still do their job. Check out the minimal
: framing used by Platt Monfort's Geodesic aerolite boats
: (www.gaboats.com)

: The people at Pocock might be surprised to find that they are
: antiques: The company has been around over a century (1911).
: check out their site at www.pocock.com . The Wooden Boat
: Foundation in Port Townsend WA inherited the mold for forming
: the Pocock shell about 2005. I saw it in 2006 when they were
: setting it up. Since then they have produced a few new
: 'antiques' and sold them to subscribers as fundraisers. I just
: found a recent webpage about these boats at:
: http://www.pocockclassic.com/ or try
: http://pocockclassic.com/Pocockbrochure.pdf which shows the old
: mold.

: There is a central frame of sugar pine which serves as thwarts and
: replaces ribs. As i recall, the crossection on these pieces is
: only 1/4 " to 3/8". More like toothpicks than ribs!
: The deck is of a thin fabric. Fabric and hull are varnished. no
: epoxy. No fiberglass. Just strong wood.

: You would get a lot of strength by laying the two layers at 45
: degrees to the centerline. They would cross each other at 90
: degrees. Going from one gunwale to the other you could probably
: fit the strips fairly quickly. Bead and cove just might be
: practical here. Quickly applied square -edged strips which don't
: quite fit together might leave big gaps with a single layer of
: strips, but when you put on a second layer--even if the seams
: are not very tight, the only areas which might leak are the
: small points where neither layer covers. Those small points will
: be filled by your glue or epoxy, or sawdust and varnish as you
: fair and finish the hull.

: Starting at the keel and working to the gunwale, with each side of
: the boat stripped in a herringbone pattern gives a central seam
: which can be backed by an internal keel or keelson. The second
: layer again starts at the keel, but goes 45 degrees in the other
: direction. The boat has an intersting diagonal pattern. The deck
: can be stripped herrigbone to match, or by laying straight
: strips.

: The idea of crosswise weaving of fibers, split wood, or wide plant
: leaves goes back to antiquity. The earliest common reference to
: this is the biblical reference to Moses being placed in a
: cradle-sized boat. Same pattern, but we are not weaving the wood
: strips (they are too thick to bend easily).despite all the seams
: and joints, woven baskets can be made which will hold water--the
: fibers swell to seal the junctions.

: Hope this helps

: PGJ

Paul,

A boat sitting empty at rest in calm water indeed requires little strength, one with a couple hundred pound person in it with big waves might require slightly more strength.

Bill H.