2014-10-21

Cutting the Backbone - Part Two

Following the successful completion of the aft backbone, I turned my attention to the forward end. The replacement keel timber I got from Gannon & Benjamin turned out to be quite a few feet longer than would fit on Dad's trailer, so we cut it shorter at the sawmill up in Massachusetts. By a very lucky coincidence, the offcut turned out to be almost perfectly sized to become the stem! Here, the pattern for that timber, which forms the forward curve of the bow, is overlaid atop the piece. I spent quite a while positioning it to make sure it avoided as many knots -on both sides- as possible.


Having positioned it to my satisfaction, I traced the pattern, and less than an hour later, had roughed it out with the Prazi:


You may also notice that the stock has been planed between the first and second images. This was done with a stationary shop planer whose feed mechanism failed about halfway through the job. It took too grown men (Dad and myself) to shove that thing through the machine for the remaining passes with pure muscle power. The scorch marks you see above are from when it got stuck and/or we got exhausted. Good times.

Next, it was the stem knee's turn. I applied yellow paint to all the cut out edges in order to prevent the moisture that's trapped in the wood from escaping quickly along the fresh cuts. If it dries out too quickly, small cracks (known as 'checks', in the jargon) will form on the surface.


As I cleaned up the Prazi's rough cuts with the radial arm saw, I noticed a very interesting property of Angelique: When cut with a blade rotating in one direction, it turns quite dark, while when cut in the opposite direction, it's almost pine-colored. Even more fascinating, the contrast faded very quickly from the surface, leading me to believe it has something to do with moisture content.


The stem itself has some pretty tight curves that are a challenge for a circular saw to navigate. At one point, while cleaning up that piece's rough edges, I tried to turn the saw through too narrow a radius, and it kicked back hard, taking a decent chunk out of the inside of the timber. Given the size of the piece, however, it's only cosmetic (and fixable). I'm glad this is all that happened; had I had less control over the saw, my hand wouldn't have fared nearly as well!


The forefoot, which connects the stem assembly to the keel, is an oddly-shaped piece that tapers from narrow at the forward end, to a foot across at the aft end. Due to the difficulty in sourcing an appropriately wide piece of timber that didn't include the center of the tree, I glued it up in Dad's shop using three smaller pieces and resorcinol. Before mating the pieces, I made sure that the rabbet line would not be crossing any glue joints, all of which will be inside the hull in the finished boat. When assembled, it will also have a bunch of massive bronze bolts backing up the adhesive.


At one point in the assembly, I ended up transporting timber for the entire forward backbone - forefoot, stem knee, and stem, plus patterns and tools - in my VW Jetta. 

My poor, poor station wagon!


With the forefoot assembled and planed down to its lines, and my friend Jon holding the stem pattern, I finally was able to get my first glimpse of the hull's profile.

OMG, it's actually starting to look like a boat!


With these done, there was only a single timber left to shape -- the biggest one of them all!





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