The wood for two boats worth of keelsons, stringers gunwales and inwales begins as 7-foot-long sections of beautiful clear douglas fir donated by Steve Reese . . . but since the boats are 12 feet long, all the pieces must be glued together with a long diagonal joint with a slope of 10:1, called a scarf joint. This photo shows the many scarf joints in progress in Scobie's shop, a week before the March intensives week at PSCS.
The plans for our “Snowshoe 12” ultralight canoes.
The tool table.
Joy cutting stringer notches in the cardboard station molds
Scobie gives Josie some instruction in using the saber saw to cut out pairs of station molds
The beam on which the boat is constructed is called the 'strongback'
The stems glued up from oukume marine plywood and clear grain cedar, two boats = four stems
Toward the end of the first day, the workspace had been set up, the master line created on each strongback with a tightened piece of kevlar thread, the station molds traced and cut, the station molds mounted on the strongback and aligned using the master line and a projecting laser level, and the stems, keelson and gunwale are all clamped in place.
Beginning to add the douglas fir stringers
Scobie, Joy and Simon, two gunwales, and two stringers installed on each side.
Joy helps fit a stringer-to-stem joint
each stringer must be cut to a very custom tapered end to fit perfectly in place against the side of the stem.
The canoe's shape begins to really show once there are three stringers in place on each side.
Kindly morning light on the beginning of the second day.
Joy tweaks the last port stringer nearest the keelson before the epoxy sets up hard.
Chloe inspects the last stringer joint on the second boat.
one of many, many, small batches of industrial 5 minute epoxy. It won't win any contests for smelling nice, but it sure gets the job done fast, strong, and waterproof.
finally all the stringers are in place.
The boats must be exhaustively sighted from each end to be sure that the stringers lie fair on the molds (that is to say that all the curves are continuous and there are no awkward or assymetrical deviations in the lines of the boat)
A sighting party . . . learning how to judge all the curves for fairness and symmetry.
Joy sighting from the stern to check how 'fair' the stringers are lying on the molds.
Rose takes a turn at sighting the curves
One tired pirate . . .Rose takes a rest from sighting the curves.
Once a stringer is shimmed if necessary and confirmed fair, it can be taped down to fix its final position
Rose and Joy taping down stringers
Now that the stringers lines are approved, the gang joins in to tape every crossing of stringer and station mold.
Let's see, 10 ribs on each boat, and six station molds on each boat times two boats makes 120 tape 'butterflies to make and apply... that's a lot of tape.
it's a taping party
The elegant canoe shape is now fully apparent as the stringers are all confirmed fair and taped down to their station molds at each and every crossing. This makes the boat ready for ribs, the curved cross members that get installed every seven inches from stem to stem.
The best of our rib stock. Each rib must be steamed and bent to the exact curve of it's position on the canoe. Consequently, the ribs have been cut from knot-free, straight-grain, sapwood ash (meaning the wood furthest from the center of the tree) This is perfect 'bending stock', and should respond well to the steaming process. While some of the students have been working on the boat frames, others have been been laboriously sanding ribstock to be round on all edges which helps avoid having the rib crack or split when it is bent to shape after steaming.
The lower grade rib stock with less straight grain will be used for less demanding curves.
The steam box: the hotplate boils a pot of water whose steam is funneled into a box containing 5 or 6 ribs at a time. The ribs get about 20 minutes of intense steam before being removed.
The steaming setup.
Alex pulls a color-coded rib from the steam box.
Chloe loads more ribs into the steam box. Steaming and installing the ribs efficiently is a time management challenge, and Chloe was our chief organizer for this task.
Scobie and Kellen bend a freshly steamed rib into place. Gotta work fast, as the rib only remains flexible for about 1 minute after coming out of the steam box.
Bending another rib into place to exactly match the profile of the boat.
Kellen, Alex, Scobie, and Joy discuss strategy for gluing the steamed ribs in place.
Joy and Kellen work to gether on a rib.
Joy sets up a rib for gluing.
Joy scavenging clamps for the next glue job.
Joy inspects the clamping job on the ribs.
Sighting again after installing ribs.
Applying glue to every crossing joint and clamping it to cure. Total: 208 joints per boat.
teamwork and coordination of tasks keeps things clicking along on the second-to-last day.
The 'omega' shaped “clamp-its” are plentiful, inexpensive, and can be applied one-handed: an amazingly convenient aid for holding the glued ribs in place for curing.
Mixing up more batches of epoxy.
rib gluing nears completion, Chloe and Scobie working on the last rib near the bow.
finally, one of the hulls is ready to remove from the station molds!
A proud team holds their creation: strong, light, and beautiful curves everywhere.
Joy celebrates, and demonstrates how light the hull's frame is.
More hull details are added on the last day, inwales are in place, breasthooks are glued in, and floorboards and thwart are being fitted.
The breasthook of oukume marine plywood is fitted into the bow of the boat, and glued with excess epoxy to seal and strengthen the joint.
The epoxy is sanded off to fair the breasthook joint flush with the inwales, gunwales and the end of the stem.
breasthook joint, sanded smooth.
Hanging the finished frames on the afternoon of the last day. I'm really proud of the boatbuilding intensive students. We accomplished a huge amount of building on the two canoes in just 5 days. They'll continue to get worked on in any off time through the spring, and will be featured at the Student Showcase, and at least one boat will be launched and paddled before school is out.
Calculator Dictionary, a word game by Chloe and Alex, played during breaks and slow times.
