Photographic Evidence of Progress

Here's the Dart 16' kayak bottom panels, joined by hog and cable ties and trussed up with various ropes and ratchet straps to force the roundness into her bottom. It looks brutal, and it is.

Overnight, one of the screws holding the panels to the hog burst out, leaving a nasty kink in the panel. I managed to get some 60 grit paper in through the gap and cleared away as much semi-cured epoxy as possible. I then drilled a 6mm hole through the centre of the affected area and re-packed the gap with fresh resin. Finally a 6mm bolt with a big washer on the back and a spreader of 9mm ply on the top forced the panel back into shape.

I've just finished planing the fair curves to the chine edges of the bottom panels. Next I need to drill all the holes to stitch in the side panels. I've also cut out the bulkheads so the next week should see some big changes. I'm close to finishing the footrest for the 14' Dart kayak, a little work is required for the rail it will be mounted on and then I'll be ready to reveal the design.

Catchup

I seem to be falling behind with the blog entries. I think the main reason is that I want photos to help describe a process or an idea, but either don't take them (because I forget or the process is too messy to involve an expensive digital camera) or because I get a bit fed up with the whole download - crop - resize - rename - upload process involved in posting them.

So here's a text only catchup...

On Wednesday I managed to screw the remaining forward portion of deck in place and I removed the still-damp towel to let the wood dry whilst in its new curve.

On Thursday and Friday I was too tired and did nothing - sometimes you just need a break.

On Saturday I only had a couple of hours, so I marked out the position just ahead of the forward bulkhead where I wanted to mount an inspection hatch and then I unscrewed the deck. This took a while. I then trimmed the deck up to within half a carpenter's pencil width of the hull with a new neat cutting jigsaw blade. I then swapped to the thin curve-cut blade and cut out the inspection hatch hole. I also prepared a piece to become an eye for the bow toggle - more of this later.

On Sunday I epoxied in the toggle eye and primed out the underside of the deck with plain epoxy. This was a hassle because it was very windy and all sorts of dust and leaves blew into the garage entrance and stuck the the tacky deck. Also, the wet of the resin caused the deck to try and curve back in the opposite direction of what was required. I quickly mixed up some epoxy and microfibre blend which I applied to the inwales, cockpit stringers , forward deck beam and forward bulkhead. Then it was on with the deck and in with all those screws again. Earlier my son Samuel had helped me take all the screws out of the scrap pads, put shiny brown parcel tape on one side of the pads and then put all the screws back in again so screwing down the deck could be achieved whilst the epoxy was still workable.

Torture Chamber

The main method of construction on the kayak up to this point has been stitch and tape. Pieces of plywood have been cut to shape and stitched together along there edges with cable ties before a permanent fixing of glass fibre tape and epoxy resin was applied. Another related method is called tortured ply, where compound curves are forced into the plywood. Its relatively easy to get a sheet of ply to bend in one direction at a time, so boats designed for this method of construction have panels shaped as sections of cones or cylinders. But the deck on the kayak is convex across the beam but has a concave sheer, the profile of the top edge of the side panels.

Last night I started putting on the deck on the forward end of the kayak. I screwed an oversize sheet in place at the halfway length of the cockpit. this allowed be to strap the middle section of the sheet roughly and draw an outline to trim the sheet to - still oversize but now by 30-50mm all round.

More screws were placed along the inwales working from the midships forward, and the stresses on the screws got greater as the curve was formed. I used scrap ply packers under each screw to prevent the deck springing back and popping all the screws through. As I approached the forward bulkhead the gap between the inwale and the deck was getting bigger and something needed to be done. I persevered for a while with a couple of ratchet straps holding things down, but it wasn't going to work.

At this point I took of the ratchet straps and then rearranged 3 straps over the top of an old towel that was soaked in hot water. The idea is that the warm and wet environment softens the fibres of the ply and makes it more agreeable to the compound curves being forced upon it. Wooden packers over the inwales concentrated the ratchet straps' force in the right direction while rags protected the deck and hull from the heavy metal hooks and ratchets. While tightening all this lot up, holding the ply with one hand and most of my body and tensioning a strap with the other hand, there was a pinging noise and a sharp pain in my shoulder. The torture victim had fought back.

I don't know what the outcome of all this was, I dared not look in the garage this morning so I'll conduct the post mortem tonight.