Tuesday, 5 February 2013

Stems, Keelson and Chines

Pinning the ribs

Each of the ribs is pinned in place with an oak dowel drilled through a blind hole in the gunwale.

Forming the stem plates

The stems are shaped out of 25mm thick timber (in this case yellow pine).

The first fixing to the gunwales is by an 'V', 'Y' lashing in artificial sinew.  The final part of the lashing turns the 'V' shape into a 'Y' (above) and adds considerable force into the lashing to bind the stem both vertically down and back into the gunwale horizontally.

Keelson and Chines

The Keelson is then attached to the stem plates at both ends, and pinned in place (below) with oak dowels at opposing angles to lock the two pieces of timber together.  Apart from scarfing the gunwale timber together originally to get 17' lengths, no glue is being used in this project, (just dry dowels, and artificial sinew!).  I am amazed at just how robust the construction is as the various components come together.  The traditional build technique described so well in the Chris Cunningham book is designed to be strong, but also 'give' and flex to the pressure of waves.

The Keelson and two Chines are held in place with a running square lashing in sinew.  The lashing crossed itself before continuing to the next rib and in doing so puts pressure into the binding.

The two chines are carefully positioned to get equal and maximum clearance away from both the bottom and the side of the ribs.  If the skin touches the ribs with the water pressure the kayak will quickly develop the 'hungry dog' appearance with rib bulges - not very ship shape!

The lines (above) indicate the path of the eventual skin.

Turned over and ready to continue with the deck.

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