: Andrew, I read the article that you wrote for the NSW Sea Kayaker Magazine.
: It is very informative and very well written. I really like the way you
: have refrained from showing any pictures of the cutwater and skeg in Part
: 1 of the article. The pictures in the next issue that show these aspects
: of the kayak will make for a large "wow factor" I would think.

The "wow factor" is something I look forward to, though I was originally seeking it only in the New South Wales Sea Kayak Club. When Part 2 is published in issue 44 of the club magazine (early December) it will be officially published in parallel on the club's web site (http://www.nswseakayaker.asn.au).

: Please be sure and post a link when you have Part 2 complete, I'm looking
: forward to reading it.

I'll post part 2 unofficially long before the magazine's December deadline. I'll include details of the two sail designs and on-water shots, hopefully including surfing. Plus a performance review - something that we normally lack with owner-built kayaks. Benchmarks will be CLC 17 and Pygmy Coho, so that we can all talk the same language.

: I am really impressed with the look of the modified cockpit design that you
: have used. I too have not cut out the cockpit because I had visions of
: doing something similar to what you have done. How much larger did you cut
: the cockpit opening than what is shown on the plans in order to make the
: style of cockpit that you did? How did you determine the shape of the
: additional panels that you made for this style of cockpit?

The cockpit cut-out size was simple in principle, but more complex in practice.

I traced the outside and inside edges (including thigh braces and seat-back position) from a Perception Pirouette. I checked against a Pyranha Stunt 270 and a Perception polo bat. These are kayaks which I wear, not just sit in.

The next step was to decide what kind of coaming I wanted: stacked ply or ply on edge or strip. I chose ply on edge, so two vertical pieces of ply on edge (2 x 3.5 mm = 7 mm) with a 19 mm (3/4 inch) wide underside to the coaming lip, which totals 26 mm (1.025 inches).

I traced the outside edge of the coaming pattern from the white water kayaks directly onto the deck, maintaining the original centre-line and Eric's designed position for the seat back. The rounded ends of the cockpit shape would have made the cut-out bend too sharply at the front and back, so I took tangents off the "corners" of the coaming shape so as to meet the deck ridge further forward and aft of the coaming itself. I cut all that out with a jig saw.

Next step is to shape the insert. For that, I made a rough cut rectangle of ply, with an arm-sized hole in the centre, a few centimetres larger all round than the cut-out. The direction of the grain should be across the kayak, to allow the ply to bend with the shape of the cut-out and to be more rigid across the thigh braces. This is true for marine ply, but lauan door skins have a different relationship of stiffness and lauan would probably need to have the outside grain oriented lengthwise.

The rough-cut rectangle was strapped to the oversize cockpit area, so it deformed to fit the curvature lengthwise and lie flat cross-wise. I traced the cut-out shape from the inside, took it off, and cut it outwith a jig saw. I then stitched it in place from the outside and filleted it from the inside.

I then re-drew the whitwater cockpit shape onto the insert, to get the curvature of the front and back of the cockpit coaming, drew a line 30 mm inside this for the inside shape of the coaming, drew in the thighbrace shape and cut out the waste with the jigsaw.

At this stage, I glassed the hull and deck (including across the insert) with 135 gsm (4 ounce) glass cloth. The insert was then an integral part of the deck.

I had chosen to have a vertical ply coaming. In retrospect, a stacked ply coaming would look just as good adn it would take about 20 hours less time to fabricate.

To make a pattern for the vertical ply, I cut short strips of cardboard and hot glued them vertically to the cockpit insert, then took this curved strip of card off the insert and laid it flat onto ply, in such a way that the grain of the ply ran across the strip (to make it bend around the horizontal curvature of the cockpit). I marked off the bottom edge, then scribed off the top edge at 19 mm high (3/4 inch).

I stitched and glued one layer of vertical ply strip right around the cockpit edge. When this was set, I removed the stitches and glued and clamped the second strip to the first. The glueing area on the top adn bottom of these strips was only 7 mm wide (just over 1/4 inch), so I figured that the entire coaming would need to be glassed over completely.

The coaming lip was traced oversize from the original white water kayak pattern onto ply and cut out oversize on the outside and undersize on the inside, then glued and clamped in place. I used a Dremel with a 13 mm (half inch) sanding drum to trim the indside edge first, then scribe the outside edge 26 mm from the inside and Dremel this back too. A Sandvik sandplate was very useful for final fairing of the outside curvature.

I made thick fillets (9 mm radius) on the outside lower and upper corners and radiused the inside edges to about 5 mm radius with sandpaper. A plane was less useful, because most of the edges of the coaming lip are cross-grain.

I then glassed the inside of the cockpit from the sheer clamp up to the inside vertical face of the coaming, another piece from the inside vertical face of the coaming to the outside edge of the lip, another from the outside edge of the lip right across the two fillets and down to a masking tape line on the deck at the edge of the insert.

Despite being only one or two layers of 3.5 mm ply, this coaming is easily strong enough to pick up the kayak without any flex.

It fits a "standard keyhole" white water kayak spray deck and gives me white water kayak quality of fit.

It looks good, too, even if I say so myself!

If you choose to go this way, Ken, then I assure you that it won't be anywhere as easy as stacked ply. Make sure that the kayak you copy the coaming shape from fits you exactly.

: Sorry about all the long winded questions. My wife has been calling the kayak
: "the obsession" maybe she has a point. I wonder what she'll call
: the next one I have planned?

Ditto, the long winded answer.

Obsession? Your wife can't call it that until it reaches the 300 hour mark. Mine is up to 315 hours. This is an honest 315 hours, because it includes shopping for bits and travel time, just as the honest cost of $1270 includes over $90 in tollway charges as well as pump, battery, deck lines.

: Have a great day!!! Thanks again.

: Ken