Construction of the Kayak One hull borrowed from 'stitch and glue' plywood method, but there was no stitching.  The Kayak One method was more 'clamp and glue.'  In retrospect, the build might have been less stressfull if I'd used section frames as a female mold.

Hull Build

Using batten to mark fair curve
Using hacksaw to cut EPS.  Hacksaw wasn't too good for straight/fair curves.  Later proved useful to cut tighter curves.
Using first side panel to layout second.
Using Stanley shurform with ss microblade to true up two side panels.
Wow, it is starting to look like a boat.
In this side view glue lines, where I glued broken EPS, are clearly visible.  This glue is much stronger than the EPS, so later I switched to using Gorilla Glue.  The Gorilla Glue is much easier to use than mixing thickened epoxy.
My new Japanese pull saw, Ryoba, cutting clamp.
Using batten as a quide to get sides closer to a fair curve on top edge of side panel.
My backyard workshop isn't very big.
Marking stop line for epoxy on inside of side panels.   This is to allow trimming at bottom edge where side will join flat bottom.
Laying out 4oz cloth on inside of side panels.
I thought it would be easier to do both sides at the same time.  Easier to make sure I was doing the inside of both panels.
Trimming excess cloth while epoxy is still soft, but no longer sticky.
Leftover epoxy, was used on a plastic water bottle wrapped with fiberglass.
Cutting to prep for bow.
I used backsaw to avoid delimination from pull stroke of Japanese saw.
The finished cut looked okay.
I smooth the cut with the Stanley Surform.
Using sides, held in place with clamps and spreaders, to layout bottom.
Checking alignment to centerline.
Holding side panels in position.
Yard is small.  Kayak is longer than yard is wide.
Ryoba saw does a good job of cutting fair curves in EPS.
Cutting bottom with Ryoba saw.
Big surprise, the bottom's sides are not equidestant from the centerline.
Hard to believe it is this far off, but popsicle sticks don't lie.
Stern is off too, but not as bad as the bow.
The edges of the bottom are not square.  My plan was to start with verticle sides.
This is the gizmo I used to square the edges.  Bulky and heavy but it did the job.  It is a Surform clamped between parallel surfaces.
Four ounce glasscloth used for inside of bottom panel.  The square hole in the bottom is to get butt lower.  Lowering butt, lowers center of gravity and increase stability.
It was dark by the time I finished wetting out the cloth.  This time I was a little careful/neat as I laid down some wax paper befor I started the epoxy.
Excess cloth trimmed off.  Don't tell but I used kitchen plate to collect EPS and wood sawdust for fillets.
I'm already regretting my lower the butt idea.  See the holes.
Jigging up bottom and sides in prep for putting in fillet between bottom and side.
Everthing is in place for the bottom, side fillets.
Notice clever use of my backyard fence as part of my jig.
Fillet consisted of filling inside corner with thickened epoxy, covering with 2" tape, then wetting out with epoxy.  For the thickened epoxy, EPS sawdust, Cabosil and micro ballons were added.  The EPS sawdust created a lumpy fillet, but it seems plenty strong enough.
Fillet tools: bucket, stirrer, trimmed spreader/squeege, aluminum corner roller.
Bow fillet.
Fence and spreader hold bottom and sides together while fillet sets up.
Jig for holding sides and bottom together had quite a few pieces.  I was lucky to have pieces of wood and plastic lumber left over from earlier projects.
With sides and bottom together the large amount of rocker is evident.  Only the tops of the sides have been smoothed out to a fair curve.  The bottom edges will be smoothed using the bottom panel as a guide.
I was surprised by how much the sides turn in.
Top turns in.
The first bulkhead doesn't come up to a fair curve.
Making sanding block for top of sheer panels by gluing sandpaper of plywood cut with jigsaw to radius of 16 inches.
The large EPS sawdust pieces are created by cutting action rather than by sanding action.
The overall performance of my sanding block was better than expected with cutting/shaping action giving way to sanding action as desired shape was approached.
The cutting action left some pretty big holes. I couldn't sand them all out without going past the shape I needed.
One morning I discovered holes in the EPS.  At first I was totally baffleed.  I thought someone was sabotage my kayak project.  It is most likely that I was less than diligent in my handling of paint thinner and other solvents.
I filled the holes with Great Stuff.  It worked, but it is heavier, more flexible, and harder to shape than EPS.
Holding front bulhead in place while epoxy sets.  The bow compartment is split by a panel running from the bow to the bulkhead.
The bulkhead is recessed for the footpump gizmo.
Bow hold was filled with Great Stuff foam, mostly just because I had it laying around after patching holes.  After letting the foam expand, I lifted the hull and immediately regretted adding this weight.
I later cut some of the Great Stuff foam out.
This as a frame to go just ahead of the cockpit.  The shape is designed to move maximum width higher.
Forward bulkhead, cockpit frame, and glove compartment in place.
Forward bulkhead and cockpit frame push maximum width from bottom to top of sides.
Bow hole fabricated with fiberglass formed around water bottle.
Bow hole.
Acrylic latex paint on hull and rear deck.  Hole in rear deck is for skeg.
Round hole was caused by burrowing big black bee.  The hole is about .5" diameter and 5 or 6 inches deep.  The bee couln't go out the other side because it was already glassed.
Ten ounce cloth drapped over hull.
Wetted out glass on hull.
Wetted out glass on hull.