The boat is experimental (don't ask about plans) and the parts for it were cut and built in Port Townsend to be shipped to Bermuda where it will be built.
My job was to cut the lumber kit and build the cross arms and crate all the parts for shipping.
The boat will be 20' long and similar to the single outrigger shown in this video starting at about one minute. https://www.youtube.com/watch?v=HevgDyupZeY
Solid laminated Douglas Fir was chosen was chosen for economy and strength. The beams took about $ 150 in Fir and took around 25 hours to build to the stage shown.
The weights are 16 lbs for the forward beam and 9 lbs for the aft beam. They will be shaped on the forward edges and covered with fiberglass cloth.
The beams are just under 8 feet long and seem very strong.
The laminates were sawn by bandsaw from three 2"x4"x 9' pieces of Fir. The laminates were run through a thickness planer to remove the saw marks.
I cut these laminates quite thin (around 3/16" to avoid too much spring back at the tightly curved outboard ends, but it still took a lot of force to bend all 11 of the laminates around the jig for the forward beam. I wanted the laminates to be thin enough to bend to the curve in a fairly relaxed state because I thought that the finished beam would be stronger and the glue-up would be easier.
The obvious solution was to taper the laminates, which turned out to be quite easy using the thickness planer. I was even able to match the taper to the designed taper of the beams which meant that I didn't have to cut the taper after laminating.
My planer ( a fantastic Dewalt 13" portable) won't plane wood less than 1/4" thick without raising the base with a piece of plywood clamped to it, but with that method I was able to feed laminates into the planer and slowly lower the cutter head until contacting the surface with them about halfway through and then slowly cranking the cutter head down to cut taper before raising it up again and repeating, the second time cranking a bit faster to cut more taper.
I was able to run a couple of laminates side by side and had tapered all the inner laminates before clamping the stack to the gluing jig to check the taper against the CNC cut plywood templates that were provided.
In the end I was tapering one or two laminates at a time in marked areas to achieve the designed taper.
The gluing jigs were made by gluing square-cut block to the bench with dabs of 5-minute epoxy before screwing them to the table. The blocks were aligned to a batten while the 5-minute cured.
The template would have been used to align the blocks, but I slightly softened the curve near the outboard end to make bending the strips easier.
Plastic tape (visible) was applied to the table before the batten and blocks.
After dry runs and fine-tuning the taper, the beam is ready to glue-up.
Slightly thickened epoxy (105 / 206 with colloidal silica and micro fibers) was applied to both faces of each laminate using a short nap roller that was cut to the width of the strips. The nap roller will apply thickened epoxy much faster and more evenly than a foam roller.
The glue-up was a breeze, partly because the laminate stack could bend so easily, and partly because the jig worked so well.
I used blocks of wood with long lag bolts to hold the laminate stack down tight to the table surface and used blocks under the head of every clamp to spread the clamping pressure
The aft cross arm is a different dimension and a different curve. The blocks were re-used for the new jig by cutting them down on the table saw.
The beams were run through the thickness planer to clean all the squeezed out epoxy from the fore & aft surfaces (using older blades) before rolling on a thin coat of epoxy for protection.
This photo shows the cross sections at either end of the forward beam. The laminates are quite a bit thinner at the outboard end, except for the outer laminates which were not tapered.
