Sunday, November 16, 2014

Skin on Frame Kayak: Building the Molds and Bending the Gunnels

One way to accurately replicate a boat design is to build the boat on a strongback with molds that hold the major structural pieces in the proper position.  For most skin on frame kayak building, this method is overkill, but Brian Schulz of Cape Falcon Kayak says that if you stray from the design of his F1 kayak that you'll have slug of a boat.

So, I built a strongback and molds at several stations along the boats length to hold the gunnels, chines, and keel in the proper positions.

Keel bent into place.

Molds in place.

One of the most interesting parts of building this boat was learning how to loft measurements from a drawing.  Lofting is a dead simple, logical, ingenious process that you can use to pull measurements off of a drawing.  I then used those measurements to create a series of molds and attached them to my strongback.  Here is a link to a more detailed description of lofting that replica kayak builder extraordinaire Harvey Golden wrote.  Learning a new way to define complex shapes in space is pretty much a guarantee  to blow my mind every time.

Getting the gunnels in place was exciting, because one of the most prominent features of a boat is the sweep of the sheer.  The curve of the gunnels defines the sweep of the sheer on this boat and as soon as they were bent into place, it felt like the boat jumped off the page and into my workshop.

I added tabs to the molds and used wedges to lock the gunnels in place.

The ends of the gunnels are lashed together.
Looking boat-ish.
With all the major longitudinal parts in place, I snaked the boat back through the doorway to my workshop, which is just big enough to fit the kayak diagonally across it.  This arrangement made for a few weeks of inconvenient access to my bandsaw.