: I just purchased (and have 'skimmed') Morris' and Cunninghams books on SOF
: construction, thought about adapting some of their methods to your designs
: using wood frames, recognizing how much simpler your construction methods
George,

Morris's and Cunningham's designs are based on historical models. They are modern adaptations of building methods used by aboriginal peoples over the ages. There are several other authors who have taken Greenaland and Aleut designs, measured them, and constructed modern copies of their shapes.
And, there are other builders who rely on the measurements of boats which were surveyed by social scientists, anthropologists, and museum archivists. The Smithsonian, for example, was the original publisher of the book "Bark Canoes and Skin Boats of North America", by Adney and Chappelle. If you check that title on Amazon.com you'll see that it has been reprinted and there are several publishers. It's a good book to add to your library. Some of the people who build these historic designs have never seen the original boat, but build from detailed descriptions or photos of them.

But kayak building is not bound to its past.

Just over 90 years ago a German tailer sewed up a fabric skin over a wood frame, and made the first Klepper. That company still makes fine kayaks which bear little resemblance to the aboriginal craft. Years ago Klepper settled on using birch plywood for frames, with ash stringers bent around it for a frame.

George Putz's book shows how an older design (a boat surveyed in the 1920's, and described in an article in "The Rudder" magazine in that decade) can be resurrected with modern materials.

About 60 years ago the soldiers returning from WWII found plans in the popular magazines for boats they could build themselves. There were plenty of designs for rowboats, motorboats, and sailboats. There were also plans for kayaks and canoes. These boat plans took advantage of the materials which had been the building blocks of war: Nylon cloth, fiberglass cloth and polyester resin, plywood, sheet aluminum, and so on.

About that time Percy Blandford was creating designs with similar components. You can find quite a few of his plans being offered by Clark-Craft. (www.clarkcraft.com. reviewing the pictures and descriptions on their site is a trip back in time--yet these are still very viable patterns and designs.

About 6 to 8 years ago you could find some reasonably priced software for people who wanted to design their own canoes and kayaks.

Now we are at a point where we have several viable options for building a boat. We can use a computer to establish the lines we want, then either define those lines with strips of cedar, or bend ribs to the shape we want, and lash chines to them, or we can define the shape of the boat by cutting outlines in plywood and using those forms as part of the boat--letting them support the chines.

Once we have a framework (either a real one, or a computer model) we can cover it (really or conceptually) with fabric, thin plywood, carbon fiber and resin, fiberglass, ABS plastic, birchbark, paper, or several other materials. If we have a concept of a boat frame covered with plywood, there are software programs which will spit out full-sized patterns for the plywood pieces. Then you just need to cut them out of plywood and stitch and glue them together.

Some people like to build traditional boats with traditional materials and experience that sensation. Others like to build modern boats with modern materials. and many like to take a few aspects from either end of the spectrum, and build a boat which has modern lines, with modern materials, but a historic shape. And there are other permutations--enough to suit any builder out there.

: When I actually 'got down to it', it was apparent - you've already
: done that. But I wonder if you might comment on relative characteristics
: of your wood frames to those of either of these two authors. Obviously,
: you're substituting the 'stations' for the ribs (and the 'bending'
: process), but also, you epoxy the frames together rather than lashing; I
: would assume your frames are less flexible, and perhaps 'less forgiving'?

Don't try to draw too close of a comparison. Different elements in a boat do different things. Or they do similar things in different ways.

Look at the basic birchbark, or canvas-covered canoe. The strong parts on that boat are the keel and the gunwales. Ribs connect the keel and gunwales, and the tension imparted to the ribs by bending them into shape forces out the hull shape of the boat. Thwarts connect gunwale to gunwale and keep them from squeezing in when the boat is liaded and water pressure is squeezing the hull.

On a plywood kayak the deck serves the same purpose as the thwarts, and the fillets in the seams are substantial cast-fiberglass gunwales, chines and keel.

On SOF kayaks which have ribs you'll see that the gunwales are substantial, and the ribs tie them together and transfer forces to them. Chines and a keel lashed (or glued) to the ribs transfer forces from the skin to the ribs in turn. Deckbeams serve the same purpose as thwarts.

On SOF kayaks which use frames (frequently cut from plywood, but they can be built up from strips of lumber) the top of the frame serves as the thwarts in a canoe, and replaces deckbeams. The frames are thicker than ribs would be, and because they are (thicker and) stronger they can be placed further apart.

Chines, gunwales and keel strips are sized appropriately so that they have some flex, but are still adequately supported.

Here is an analogy: Think of the difference between building a house with thick posts and beams, placed 10 feet apart, as opposed to building a house with walls made of 2x4s placed 16 inches apart. You place the structural elements where they need to be.

There is no reason to limit the discussion to wood. Tom has done some really neat designs based on frames cut from HDPE plastic, with chines made from aluminum tubing. George Dyson (check out his book "Baidarka" has similarly made kayaks from aluminum frames.

Every few years there seems to be an engineering challenge with the goal of building kayaks or canoes out of concrete. Google "concrete canoe" or concrete kayak" and you'll find lots of links ot colleges which compete in these areas.

My dates may be off on a few of these items. I'm away from my references and doing this off the top of my head, but i hope this helps to give you a historical base--and that such a base helps to clear up your questions.

PGJ