: Now, I understand that using epoxy and fiberglass increases the strengh and
: durability of the final craft, but would it not be possable to build one
: complete from wood ?

Sure thing, been done for years with open canoes,(or canadian canoes if your local dictionary calls a kayak a decked canoe.) There is no technical reason why you could not make a solid wood deck for such a boat, or, you could build a hybrid with a deck of fabric, which would be lighter weight and possibly breathable, for cooler summer paddling.

I think Canoecraft has a section on the history of canoe construction which mentions this, otherwise, you might want to check some books on the history of canoes for more details.

As I recall from my readings, though, about the time that the supply of big birch trees started to become an issue, people switched to building boats from cedar strips that were nailed to ribs with copper nails. Some companies used expert carpenters who had come to the states and Canada from Europe. Others adapted the birchbark canoe building process and substituted a sheet of heavy canvas for the bark. The area between the ribs and the skin, in either case, would be filled in with cedar strips.

The cover of "Canoe Craft" has a photo of two canoes. If you look carefully you'll notice that one of them has an interior lined with ribs.

These canoes were built on large forms. The ribs were bent ( steamed first?) around the forms at rather close intervals that appear to be about 6 inches or less. Strips were then attached to these ribs. Beveled edges on the strips provided tightly fitted matching surfaces which needed only a few coats of varnish to keep out water. Actually, if they got a bit wet, the wood strips would swell a bit, and like the staves of a barrel, wedge themselves even tighter together and providing leakproof seams.

If your construction skills are not nearly as good as those of a cooper ( a person who makes barrels) you can cover the outside of the boat with a layer of canvas, adhered with wet paint, and then covered with a few addtional coats of paint.

The ribs served a structural purpose as well as providing the backing for all the copper tacks. With modern building methods, the structural purpose of the ribs is replaced by glass cloth and resin on the inside of the boat.

While you would use these canoe construction techniques, you would probably want to build from a kayak design to avoid having a rather fat boat.

There are also building techniques that use more substantial ribs spaced about 18 inches to two feet apart. The strips that make up the hull are aniled to these in the same amnner that wood siding is nailed to the frame of a house. No fancy planing techniques needed to make the edges match. Instead, the planks are nailed to each other in the area where they overlap. The closely spaced nailed are clenched (or clinched) -- bent over on the inside -- locking the boards together. The joints can be caulked if there are stil gaps, but otherwise, the swelling of the wet wood seals these. This is the technique used for building the Viking boats, as well as dories and some canoes. The modern version of this, eliminates the ribs and the wood strips are replaced with stips of plywood, which are glued along the areas where they overlap (instead of being nailed), allowing you to construct some very light boats.

There was a link a few weeks ago on this board to a compnay which builds rowing shells. They use wide planks (24 inches or more) of thin cedar, which is steamed and bent over a form. It may be difficult for you to obtain such materials, but you can glue together several narrower pieces to build up whatever width you wish. Building a steamer for a long wide plank, and also a form to bend it on might be a rather daunting task, though.

If you like the concept of building with bent wood, consider a design for cold-molded laminated layers of veneer. You would build a mold similar to one used for a stripper, but a bit undersized to adjust for the thickness of the materials that will be put on. Cover this with a layer of wood strips or lath which can be spaced 1/2 inch or more apart. No fancy fitting needed here, just get the strips on the forms. Over this you lay a sheet of thin wood (veneer). An occasional staple holds this to the lath. Add more pieces of veneer, butting them together, side by side so they fit neatly. Since the material is very thin, you can use a straightedge and a utility knife to slice through any areas where these veneer panels overlap. Remove the waste and you have a neat matching edge. NOw get more sheets of veneer and lay them over the first layer. You want the grain to go at roughtly right angles to the direction of the grain from the first layer. Pull any staples from the areas you are going to statrt with. Coat that section with glue, lay on the 2nd layer of veneer and use staples, clamps, straps or weights to hold it in place until the glue sets. Pull more staples from the first layer, cover with a second layer, and continue until you have covered the boat again. Do this whole process a third time. If you have used very thin veneers you'll need to keep going until you've built up the skin thickness to 3/16ths or thicker. Clark Craft has a plan in their catalog for a kayak made from veneer. You might want to get a copy of those plans for better information on this process. If you can avoid using staples, and you are careful to stagger all the seams, you'll end up with a hull that is structurally strong and watertight. Adding varnish merely protects the surfaces.

: This would just feel more "natural" to me.

Except for the painted and canvas-covered ideas it would look natural, too.

: Yes I know I could make a "skin on frame", but this does not
: have the "looks" of an all wooden kayak.

Not so fast here! Mike Hanks took the frame from a George Putz "Walrus" and covered it with plywood panels instead of cloth. The chines around which the fabric would have stretched became surfaces into which he could drive screws or ringshank nails. A layer of glue on these chines completes a watertight bond. Some people use a gasket at the joints. This is merely a long, narrow piece of cotton cloth or canvas, which is soaked in glue and then laid on top of the chine before the screws are driven in. The gasket fills any slight irregularities in the joint.

If you don't want to use plywood, you can use a frame from a Skin-On-Frame kayak and cover it with panels made from edge-glued wood strips. You can make a very strong edge bond by using strips which have bead and cove edges, or you can make a 1/8 by 1/8th inch rabbet in the edges of each strip with a tablesaw or router. When two strips are set next to each other, these rabbets will overlap and give a very nice gluing surface.

: Is weight the primary reason ?

No, veneer boats are rather light, but the time involved in setup is rather boring. You don't have much to look at until near the end of the building process. Boats built on thin ribs are as light as those made with fiberglass. However, you can make heavy boats with these methods, too. Without the epoxy resin coating the wood absorbs water.
Canvas covered boats get heavier as they absorb water, and a weight gain of 8 pounds or more could be considered common.

: Could you not just make the strips thinner, and build it around a frame like
: in the "skin on frame" kayak ?

I guess I answered this higher up. Yes you can.

hope this helps

PGJ