Friday, March 4, 2016

FDR chair: shaping

The construction sequence for this chair may seem a bit unorthodox, but I think the reasons will become clear as I go along.  After I glued up the blanks and cut out the side profile, I reattached the offcuts with double stick tape and sawed out only the inside of the front profile.  At that point, I shaped and refined the fronts and insides, but not the backs.  I did this in two steps.  First I shaped them by eye, then I placed the pieces side by side to get them symmetrical and the joinery surfaces parallel so they will line up perfectly.  This is somewhat complicated because the workpiece is mostly curved, frequently in two directions at once.

The process went fairly smoothly, although, obviously, white oak is a lot harder than the alder I used for the prototype (Janka hardness of 1360 vs. 590).  The douglas-fir like Ray Neufer used is a lot softer (660).  Even keeping my tools sharp, it was very slow, difficult going and I was glad that I had sawed quite close to the line.  I didn't do as well with the spokeshaves as I had hoped, especially on the wider sections at the top of the back where they were difficult to grasp.  They had a tendency to skip and chatter.  I ended up using the plane, rasp and file for most of the work and had to bear down to get them to cut.  The biggest surprise was that card scrapers worked great.  I must have done a good job the last time I prepared them, judging by the nice shavings they were taking.  What a relief and pleasure that was. 

After the initial shaping, I lined the two pieces up the way they will face each other, hoping that I wouldn't have a lot more to do and breathed a sigh of relief that there were only minor differences, less than 1/16".  Here they are:

You can see how tight the pieces are at the top and that the faces where the mortises for the side and rear seat rails will be are parallel.  Whew!

So, it may seem strange that I went this far with the fronts and insides when the backs are still rough and the outside isn't even cut yet.  The reason I did this was for joinery.  I wanted to have two reference faces before I laid out and cut the mortises and, of course, two of the mortise faces on each leg weren't even exposed until I made these cuts.  By not cutting out the outside curve I can lay the legs on their sides and have a flat stable base for making the two mortises at the top of the back and the one for the rear seat rail.  By reattaching the cut-off on the back, I can have the same stable base for cutting out the mortises for the stretchers and side rails.  That was my reasoning, anyway; we'll see how it turns out.


  1. I'm having a problem seeing this layout so I'll have to wait until you are a little farther along. That WO has some interesting graining (2nd pic) - is the back facing up in that one?

  2. Ralph, Yes the back pieces are facing up. It's a little confusing because these are the two rear legs/back pieces clamped together. They will be separated in the actual chair and the curved profile cut out on the outside of each. I can see that it is confusing. I'll try to post clearer pictures next week.

    As for the grain, yes it is unusual. This is perpendicular to the quarter sawn face on the side and angling down more than 4". I was quite surprised by how it looks. My efforts to match the grain weren't too successful because I couldn't anticipate how it would look that far down into the board. It doesn't look bad to me though, but there would obviously be an advantage to make these from a solid 4x6.