First Folding Kayak

Submitted bycliff.landesma… onThu, 11/15/2018 - 16:54

I have designed my own version of a folding boat, inspired by the Oru Kayak. My design has a few advantages. The design is "pure origami." If made with cardboard or coroplast (which folds), it does not require any cuts to a 6' x 12' rectangular board. If made with wood (which is rigid), it requires cutting the 6 x 12 rectangle and joining with waterproof joints. The design is simpler than Oru's.

My aim is to construct a boat that costs less than $100 in materials, lasts for at least 25 journeys, folds into a box about 2' x 3' x 1' and can be finished in less than 8 hours (not including drying time). I would like the boat to be aesthetically pleasing as well. Think Oru, but using either cardboard or thin plywood as the core. 

I am not an experienced boat builder, so guidance would be welcomed. I am considering using baltic birch plywood and fiberglass tape to create waterproof flexible joints. Can tape alone be strong enough to hold the wood panels together? Will I need to reinforce with metal hinges?

I am attaching a link to a 1/3 scale cardboard model and a diagram (posted to Facebook).

Thanks for any suggestions!

https://tinyurl.com/ybvdcqm8

--Cliff

Cliff, do a google search for "Boy Scout folding kayak plans" or just try this url:

http://troop37losaltos.com/Portals/0/Kayak%20Build/Kayak%20Plans-revise…

Now, ignore their design, but carefully read their construction methods.

They have been successfully using canvas cloth for the flexible hinges.  This fabric is attached to the plywood with a contact cement then painted with a latex paint, which keeps out the water, but remains flexible for years. They use rather wide strips of canvas so the attachment area on the plywood is quite wide, and robust. Once the plywood parts are cut the construction tools are masking tape, glue brush, paint brush and maybe a mallet to make sure the contact cement gets a good grip. 

I think with your design you could cut out the shapes along the fold lines (maybe need to cut inside some of the lines to allow room for the folding) then reattach the pieces with canvas strips, allowing some gap between the pieces. You would probably need to experiment to see how much of a gap you would need between pieces to allow folding. 

Notice that the Boy Scout design uses bulkhead pieces which are forced into the unfolded envelope. These provide structural support and force the boat into its shape. You may need to add some way to hold your folded boat together, and then shove in bulkheads or stretchers to tension the structure.

Just some thoughts, Hope this helps.

PGJ