Ok, it's a Sport Tandem.. but I made some mods to the stern and deck so I'm calling it a Sport Double.  Here's a prettier pic (Suwannee Over the Bough) from the Suwannee River Challenge '14.  It's from a GoPro angle. I assure you we were paddling, 52 miles in under 10hrs total.

Nice looking boat. Great job. What mods did you make, besides the obvious in/onlays? JRC   

I made few changes to the boat:

I like the Smart Track rudder system, but it needs a flat, perpendicular stern to work properly.  So I extended and made the stern plumb

I wanted to reinforce the deck with fiberglass inside so I butt jointed the deck panel so I could put a 1/16 inch of chopped fiberglas/ceramic aluminum bead coating on and install it in one piece while wet.  Yes, it took "all hands on deck" to transfer it from work bench to kayak.  (6 people to be exact)  This also forced the deck camber to remain constant from bow to stern.

The veneer was all placed after the boat was built but before it was fiberglassed.  This allowed me to overlap the deck AND hull fiberglass at the chine.

Here's the bolt glued on via heat reactivation, a method I learned from this forum.

I'll post some of the other techniques used soon.

Thanks for looking

   Here's a more refined, but not finished view of he stern mod.

Nice work. How did you hold the camber in the deck piece while you were working the fiberglass?   

   This pic will help.  This is the underside of the bow hatch.

The fiberglass was 1/4 in cut strand to which I added ceramic aluminum sphere powder as a thickener and suspension for the fibers in epoxy.  This was layered 1/16 in deep to within 1 inch of where I had marked the hull outline. Yes, I strapped the deck to the hull and made a pencil mark all around.  I then covered this layer in clear plastic that was cut to size for each compartment, avoiding the deck supports and bulkheads. The plastic did a great job of giving a very smooth finish.  This is very important when using cut fiber fiberglass as otherwise you will end up with a 20 grit sharp as glass surface.  This was the sandwich that my family +1 transfered from the work table to the hull and screwed into place.  I buttered the chine, deck support and bulkheads with wood flour thickened epoxy.  You would not want to use the aluminum fiberglass mixture here as it would be a bear to sand and clean up.

I'm using hidden hatch hold downs to not spoil the deck work.  Even with all the veneer, fiberglass and a month of cure time, there was still springback when the hatches were cut from the deck.  This was cured with ply reinforcement epoxied after applying the requisite side pressure with my Quik-Grip clamps x 3.  Notice the ply also serves as part of the hold down as well.  While I'm at it, the epoxy soaked cotton string around the perimeter allows the limited force of the bungees to make a great water tight seal with the 1/4 x 3/8 wide closed cell foam weather strip hatch seal.

Hope that helps,

   To directly answer "How did you hold the camber in the deck piece while you were working the fiberglass? "

I actually didn't hold the camber.  I butt jointed the three deck pieces flat.  Let them cure completely, then coated it as above with epoxy/fiber mix.  This 22+ ft long piece of plywood was then lifted and flipped by 6 people to align onto the hull sheer clamps and deck supports.

Here's the stern deck profile shown as I'm clamping the cockpit to it.

Why the chopped strands instead of cloth? On the face of it, it's not as strong since you don't have the long continuous threads for tensile strength. Were you going for just abrasion protection?

Laszlo

   My concern with the cloth was taking it from flat to bent while wet and ending up with wrinkles or worse it pulling away from the deck.  I felt that if I let it cure enough to hold it would not bend correctly when mounting it.  I tested the epoxy mix and it would hold upside down without sagging or falling off.  I also feel it adds significantly to the strength as evidenced by the way it held its camber when I cut out the hatches.

I have to admit, I didn't know what to expect when the hatches came out.  I was pleasantly surprised that it only took a little clamp pressure (side to side) to make it match the ply stiffeners.  I think that shows the cut fibers do provide significant strength.  BTW, this mixture held it's shape whereas I routinely use a cured 4 oz fiberglass cloth layer on BOTH sides of the cockpit combing, over one-sided layer of veneer, and easily form it to the camber of the deck. These matrix covered hatches would never bend like that.

Kent

OK, I get it now. You were adding bulk mass to reduce the wood's flexibility and effectively cement in the camber. The wood was acting as a pre-stressed framework. Sounds as if it also does a pretty good job of armor plating it.

FWIW, once the epoxy cures to the "green" stage (leathery, dry but tacky, cuts with a razor, sticks to itself when squeezed together), the cloth will not come off unless you grab it with pliers and peel, yet it's still flexible enough that you can bend a deck or hull panels. So if you ever want the protection without the full armor treatment, it's possible. The trick is in the timing. At 80 degrees it takes about 6 hours to get there.

Nice boat, classy lightning bolt and I envy your green trees and paddling weather. Are you going to put a hammer on the front for a figurehead? :-)

Merry Christmas,

Laszlo

   How'd you guess Laszlo!  I did add a talisman for max whimsy factor.  Here's Thor wielding Mjolnir in his very own boat. His facial details were in the grain of the wood. His eyes, mouth and beard are all there.  The same with the dragon's eye and brow.

You'll notice his boat's shields are repeated on the side of the kayak too.  I'll get some glam shots when I finish reinstalling the rigging. Kent

Nice job, what weight is it finished ?

Paul 

Thanks Paul, It weighed 82 lbs as paddled in the Suwannee Challange.  Seats, Rudder, thigh braces, bow handle and painted interior.  I have since sanded the epoxy, cut and installed hidden hatches, rigged for perimeter line and put on 4 coats of varnish.  Tomorrow I reinstall the seats and put on the weather stripping for the hatches.  Then it's time for a paddle and some pics, hopefully in the sun.

Here's a pic of the suspended kayak under the dust tent for the final coat of varnish. Suspending it allowed me to do the deck and hull as one coat. I thinks it is more than twice as fast.  From this angle you can see the "Viking shields" on the hull.

Kent