Andrew,

Thanks once again for your reply. Sorry about the late response. I'm going to have to do some thinking about adjusting the cockpit size. Although I really like the idea of the keyhole style cockpit, I lack the kayaking knowlege and experience to know what a good fitting cockpit is. All my kayaking experience to date has been in rented or borrowed kayaks so I have yet to experience a properly fitted cockpit. Once I get to that step I'll maybe do some trial sizing and see what I can do with your style and a fit that works for me.

Thanks again, hope all is going well.

Ken

: 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).

: 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.

: 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.

: 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.