Snip:
: There are skin boats that have forms - just like a bulkhead except that you
: cut the middle out leaving an inch of wood all around the outside. Then
: they have stringers that travel the length of the boat and pass over these
: forms in mortices. In this case all you would have to do is fill in the
: form opening with either a fabric or solid material with silcone adhesive
: calk.

To be fair, Tom Yost is one of the best craftsmen in using and building this type of kayak. See the picture of his folder frame here:

http://www.flyfisher-kayaks.com/foldboat/foldframe.jpg

Tom has correctly noted that it works out best to create a scalloped edge for the frames to keep the skin from touching them. Trying to bring this edge out far enough to get a waterproof seal between the frame and the skin could cause considerable problems for both speed and it would also be an obstruction that could cause a tear going over logs and rocks.

: If I had to - on a challenge make a bulkhead for my Greenland style kayak I
: would use fabric and tack it in with an exectric glue gun and calk the
: he-- out of it with the best adhesive, flexible calk I could find filling
: in the gaps around ribs etc. The main problem would be the front one
: getting in or working through a front hatch opening of some type.

Actually, I think that a fabric bulkhead is possible and may be practical. I do not know the design used by Pavia Lumholt (on the Qajaq USA board) because he has not let the cat out of the bag yet. However, in thinking through the problem, I believe it would be possible to sew a ballistic nylon bulkhead between the stringers, keel, gunwales, and deck stringers; using extra blocks on those members as sewing surfaces as necessary. Enough cloth would be allowed to remain so that the skin can be sewn to the bulkhead between these longitudinal members, plus a little slack so that the shrinkage of the bulkhead would not pucker in the kayak's skin. All this can be varnished and made waterproof. The only thing which remains is the area between the skin and the longitudinal members at the location of the bulkhead. Some form of waterproof material (perhaps nonvulcanized rubber like the sealant used on campers) needs to be slipped between the skin and the stringers, etc to seal this area. (The gunwales may need to be designed at less than a 17 degree angle or the ribs built in such a way so that the skin is in contact with the full width of the gunwale.)

This construction can be rather well done with thread and good sewing. Other than a sealant as described above, no other materials other than those usually used in a kayak need be used.

Of course, provision will then need to be made to have a hatch for the area so that it can be completely dried after use.

I can't wait to see what Pavia has come up with.

Rick