As I said in my previous blog I found the shaping of the chair parts to be more complex than the jointing. A lot of the subtlety of the chair comes from the play of light on various curves and facets. The flow of the grain on the crest rail is also important.
I completed all the jointing prior to shaping the parts. This meant I had straight reference edges to work to.
The front legs were tapered at the bottom, the back edge by 5mm and the inner edge by 3mm, at the top the inner edge was tapered by 6mm leaving the top square in section.
After the tapering was complete the top of the legs was worked with a block plane and spoke shave so the profile changed from square lower down to circular at the top, concentric with the dowel hole in the top of the leg.
The basic shape of the back legs was roughed out on the band saw then trimmed using a curved jig on the router table. The top outer edge of the back legs was tapered 6mm, the inner edge 3mm, the bottom inner edge 4mm, all done using a jack plane. Once the tapers at the top had been formed the profile could be worked.
Following the work on the front legs I mistakenly made the top of the back legs too circular, it would be better with a more defined squareness. It is tempting to smooth things out, the problem then is that you lose the play of light on the changing facets.
The crest rail required considerable head scratching. The rail curves in two dimensions and is tilted off vertical. It would have required quite a chunky piece of ash to cut the shape from a square section piece. So a 45mm ash section was sandwiched between soft wood packing pieces and the corners removed to form a new rectangular section so that the ash was held diagonally in the section. This allowed the rail to be cut from the fabricated piece with the ash grain orientated to get the best effect.
To determine the angle and size of the piece in the sandwich I drew out the positions of the highest and lowest sections of the rail using sketchup, I could then draw in the position of the ash piece to ensure the rail was all ash with no bits of softwood included. Even after this it took me a couple of goes to get it right! Determining how the grain pattern will appear in the cut rail is “tricky”. I need to practice cutting a few more to experiment with different grain orientations.
The shape of the rail was traced onto the blank on the top surface and the front surface using two templates created from the drawing. Before cutting the rail the position of the dowel holes for locating the rail on the top of the back legs was determined using dowel points in the tops of the legs. The holes being drilled on the drill press. The rail was cut out on the bandsaw, requiring four cuts in all, two in one dimension and two in the other. The parts being taped back together each time to maintain the square section and the tracing for the cut. I hope the series of photos clarifies this process.
After band sawing the shape was refined using a spoke shave and scraper. Holding such an awkward shape could have been tricky, but I was helped by the dowel holes previously drilled. Similar holes drilled in an off cut allowed me to locate the rail on the off cut held in a vice.
The chair is starting to come together now. The main things left to do are the fitting and shaping of the arms and the laminating, shaping and fitting of the back splats. I will deal with the back splats in my next blog.
Thanks for following my VM Chair Making Project and a very big thankyou to those of you who share my project with your friends (Hint: you can use the social sharing buttons just below these project pics – Thanks!)
If you like what you've read or know someone who would,
please help me spread the word by using the buttons below