The next step in the project was to create the hinge joint. As I mentioned last time, this involves the removal of alternating 45 degree wedges of wood from both sides of the board. As you can see from the photo above, the layout for this forms a sort of small checkerboard whose components are reversed. On the near end, you can see that the area to be left matches up with a removed area on the opposite side. This is CRUCIAL for the joint to work. This is a piece of red oak that has been laying around for over 20 years, and is VERY well seasoned. This made matters difficult for my new 25 degree Sorby Excelsior chisels, which still had a bit of a decarburized surface, and thus a still somewhat fragile edge. This will improve with time, but for now caused problems. I ended up resorting to my old 30 degree Marples Blue Chips since side clearance wasn’t a problem.
Once these were cut to my (somewhat) satisfaction, I turned my attention to the decorative contours of the top and bottom. This was the perfect job for my new turning saw with the 10 TPI blade. If you’ll notice, the pattern was redrawn a little lower on the wood. That’s because I let the saw get too far out of the lines the first time and had to reset everything. It seems to have a tendency to keep going once you get it started in a given direction. I tried tightening it a couple of turns, and this tamed things. It’s still important to remember to use full strokes and continue stroking as you turn.
Next came the fun part – the resaw. I, like many of you, was dreading this part. However, I took things slowly and it wasn’t too bad. After scribing the center all the way around the edge of the board, I started sawing at a corner. Once this was well established, I tilted the board away from me and extended the cut down the near edge, using the existing kerf as a stabilizing guide. When I was near the joint I stopped, straightened the board back up to vertical, and extended the kerf across the top of the piece. Once I had made this connection, I turned the board around and worked the kerf down the other side in the same manner. After that, It was just a matter of working the cut down through the wood. I continued the same sort of alternating strategy as I went, trying to keep things even and finishing with horizontal sawing to take out the “triangle” in the same manner as a tenon. This is one time that I have wished for something coarser than my 6.5 ppi ripsaw. It would have made life easier.
When I was down close to the joint, I used Roy Underhill’s idea of holding the kerf open with a couple of framing squares while I carefully sawed my way to the point where the knuckle joints intersected the center line. I would saw a bit, and give the squares a twist – nothing. Saw a bit more, and twist again – nothing. Eventuallly, I heard a heart-stopping CRACK that either signified success or failure. When I opened my eyes, voila! It’s ALIVE!
Of course, the job was far from over. First, one side had to be cut down to form the lip that the book would rest on. Secondly, there was a fair amount of saw tracks to remove, although not as much as I expected. Thirdly, the knuckle joints were far from perfect, and needed some cleanup. My chisel skills left something to be desired, and I resolved to improve them before someone saw this one and wanted me to make another.
After chiseling most of the rough surfaces of the knuckle joints smooth, I was faced with the task of cleaning up the saw marks. This was not as easy as it might seem. Since the marks are on the inside surfaces, the stand must be in the open position to plane and scrape effectively. As you can see from the photos above, there is really no good way to get in there with either plane or scraper, and the knuckles of my right hand testify to how sharp the edges of freshly cut wood can be. Nevertheless I persevered, first with a jack plane across the grain, followed up by a scraper with the grain. It was a little more work this way, but the surface was eventually smoothed up.
And here, at last, is the finished product. The finish boiled linseed oil, which should give a nice golden patina over time. Yes, I know the wood is wormy, but it was the only piece of stock available at the time. If there were a few more worm tracks in that side, it would almost work as an “antique” design feature. In a serious one of these, I would probably incorporate some form of carving for decoration, but I’ll let this one stand as it is. Besides, my wife wants it to hold her book in sewing class.