Yewkandooit - 11 1/2' flat bottom lapstrake canoe.

This is a write up of a design inspired by Fritz Funk's Wackie Lassie. It hasn't been built yet. (As of  6/10/ 02.)
JoePirate.jpg (78400 bytes) This is a shot of  Fritz's Wackie Lassie that he builds with school kids in Juneau Alaska. His has a dory transom, decks and the gunnels are made from those kid's foam pool toys called "fun noodles" or "wackie noodles."
JnMdouble.jpg (45595 bytes) Here's my version of the Wackie Lassie without the decks or the fun noodles. It's made with 1/4" luan ply and cypress rails and chines and transom. I like the boat but it weighs 40 lbs - which is a bit on the heavy side I think. So I sharpened my pencil and tried my hand at making a lighter version of her.
canoe11b.jpg (37925 bytes) This version is a light double ended, double paddle canoe with about a 250 lb capacity. It's about as simple a boat to build as there can be - hence the name. 
canoe11bviews.gif (3724 bytes) Here are the three views as generated by Greg Carlson's Hull program. It's symmetrical end to end.
canoe11bply.gif (10468 bytes)
This is a 1 and a half  sheet boat.  One sheet of 1/8" ply (3mm) provide the sides, decks, bulkheads and a  half sheet of 1/4" ply (6 mm) will provide the bottom.
sidesdetailcan11b.gif (6390 bytes)
Here are the side details. The lap joint is glued with Tightbond II and "clamped" with 1/4" staples. The gunnels and the inwales are both 5/8"x3/4" (with or without inwale spacers) The chine logs are the same dimensions and can be planed or ripped at 17 degrees to provide a flat gluing surface for the bottom.
canoe11bboard.gif (5316 bytes)
The solid wood parts can be taken from a single 1x6 12 foot long board. Sort through the stacks for the clearest board possible. This yields 6 strips of 5/8"x3/4" and then one strip of 3/4"x 1" for the keel. All but the inwales are glued and nailed "on the flat" before the boat is bent into shape.

Double ended 11.5 ft canoe – ultra-light design notes.

One goal is to get the weight down between 20 and 30 lbs with the smaller rails, keel and thinner sides.

The sides are of 1/8” ply "lap straked" with 1” overlap. The lap is glued with Tightbond II and Ό” staples. Upper strake is 5.5” lower is 6.5”. This overlap is the equivalent of a 1/4" x 1" stringer running along the middle of each side and will lend additional stiffness. Glue the overlap on the bow/stern panels before cutting them apart, or the slant for the stems will be misaligned.

An 8ft half round rub rail could be added along the lap if necessary for more stiffness. I don't think it will be necessary.

The bottom can come from half a sheet of Ό” ply, using the rotating triangles approach. (see sketch)

Butt glue the triangles with thickened epoxy or tightbond II with no battens at first. The keel will reinforce the longitudinal joint, and a 4" wide 1/8" thick butt block can be used for the athwartships joint.

The stems are 41 degrees. A wood stem could be made, but it can also be stitch and glued with the usual epoxy and glass, or with PL and glass. (I'll be doing the glass and epoxy to see how easy it would be to do "student canoes" in the evenings.)

The rails are of 5/8” x Ύ” ripped from 1 by stock. (see sketch) I've used cypress a lot because it is available locally very clear. This time I'm going to look for a pine board. It may be lighter, and what is more available to others.

The canoe is symmetrical fore and aft and side to side. This makes the frame placement easier.

The first and 3rd frames are identical, 38” from the ends... at least according to the computer. I'll see how the materials want to behave.

The rails and chine logs (if used) are installed "on the flat" with Tightbond II, or PL or Epoxy. I'll be using Tightbond II and ring nails on this one, to more closely mirror the way the kids will build them.

The side assemblies are coated with thinned epoxy while they are still flat. This will prevent any drips or runs.

The side panels are bent around the center form with the help of rope windlasses, and the stems are stitched together.

The bottom’s triangles are glued and the Ύ” x 1” keel is glued and nailed to it.

The bottom panel is slipped under the sides which are right side up on saw horses.

Gravity creates the curve of the bottom.

Bottom can be marked, removed cut and put back in place… or….

Here's an innovative approach a friend of mine is finding workable on small boats.

After making sure the sides are not racked or bent, run a bead of PL Premium around the inside side bottom joint. Smooth with a spoon or gloved finger. When set, turn hull over, trim off bottom with laminate trimmer.

Round corners and apply 2” fiberglass tape and epoxy.

Or....

Another approach still in the testing stage would work like this.

filletsections.gif (3560 bytes) Run a bead of PL adhesive inside and out. After it cures, trim off the bottom with a saw or laminate trimmer. Round and soften the slight overhanging lip with a sander, and seal it with epoxy. I'm currently testing PL Premium masonry sealant which doesn't bubble as it cures & ways of minimizing the bubbles in PL construction adhesive.

Could gallon plastic jugs be secured fore and aft for floatation instead of water tight bulkheads?? If so.... maybe they could be made to nest.

Spreaders can be 7/8” dowels with 5/8” tenons cut on the ends.

Drill 5/8” hole with a forstner bit into inwales. The boat sides need to be flexed open to install and remove spreaders. If they can be removable, the boats can be nested.

Perhaps a single slightly off center spreader that doubles as a pivoting seat back support, might work?

 

canoe11b.1layout.gif (7519 bytes) This sketch has the frame dimensions and also shows how you could do the whole boat out of 1/4" ply if you weren't going for the lightest weight possible.
 

 

 

 

 

 

 

 

 

 
 

David Beede  simplicityboats

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