Saturday, September 5, 2009

A little bit of progress

Well, I've been making progress on a few fronts lately. It's been coming slowly, but it has been coming. First, I've made the decision to build the Chestnut Prospector "Ranger" canoe for the tandem boat in my class and ordered the plans. In order to protect the intellectual property of the designer, I'll have to ask my students to buy the book which contains the plans, but that's not a bad trade-off, really as the book contains a lot of great information. It's a 15' long canoe that's just shy of 3' at it's widest point. It should feel stable but still be fairly easily paddled. A good compromise.

I'm still working on making the strongback and forms for this design lighter. I'm planning on a foam-filled box beam for the strongback that will be set on either sawhorses (stackable or folding) or benches in the shop. The top will be 3/4" plywood to allow us to screw down the patterns and the sides will be luan ply. In between will be layers of foamular insulation that are laminated to each other and the luan with construction adhesive. Periodically, there will be 2x4 or 2x6 blocks to improve the torsional rigidity. I went to the lumberyard this morning to get the materials that I wanted only to find them closed. I then went to our local "big-box" store to see if they had what I wanted. They do, but I didn't buy them there - I was planning on using construction adhesive to assemble the beam, but hadn't considered the fact that the adhesive might be incompatible with the foam. Dang. A bit more research. The forms will also be "lightened" by the removal of material where it isn't necessary from the patterns. I need to keep this light so we're not moving 140 pound of boat and strongback around. My goal is to get a prototype built before next weekend is out so I can have a material list ready for sign-up on the following Monday. The other trick is going to be organizing the shop this year to accomodate the different stages of build that are going on. We'll see how that goes as time goes on.

I've got the majority of the frame complete and put two coats of semi-gloss polyurethane on it. I think things look pretty nice, actually:

I also picked up black nylon rope, webbing, hardware, grommets, elastic and such for deck rigging. I need to bore some holes in the frame to allow me to attach carry loops at the bow and stern, deck rigging and hatch straps. My next major task is to build the foot braces and to finish up the coamings and hatch.

I'm not impressed with my first attempt at the rear hatch - the wood was wet with boiling water and then using a steam iron and damp cloth, it was steamed around a plywood form to get the oval shape. I broke the first one due to wild grain, but the second went better with no fractures. After the wood dried, I removed it from the form to apply glue, but I couldn't manage to get it as back on the frame as tightly as I'd like. The picture below is the first attempt. There are gaps between the laminations that I'm not happy with. I need two of these - one slightly larger than the other - as the hatch rim and the other for the hatch cover.

I also need another piece for the coaming, but the radii are much bigger (as is the part) and I anticipate fewer problems. I'd purchased some ratcheting straps to try to pull things onto the rim, but I think I'll go "low-tech" with a Spanish windlass to try to clamp the wood around the form as it's gluing. Sometimes the simplest ways are the best.

Tomorrow is another day and I'll take another stab at the coaming and the cover rims.

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