With the splats finally finished I can now glue the entire splat assembly to the chair base. Needless to say, the splat assembly took some time and so it's a good feeling to get to this stage. I glue the splats together in phases. I glue the center splat to the base first followed by the two inner small splats and the two outer small splats:
Because the top tenon is housed there is no pressure applied to the spat by simply clamping the crest rail on top - I insert a stick up there (which you can see dangling from the rear) to apply pressure to the splat upon clamping. After gluing the side splats together along with the center tabs this is what we now have. I did not need to use clamps for the small splats. I simply held those splats down with hand pressure for about 5 minutes.
Now its time to shape the crest rail! I rough cut it down to length and rough cut the back based on the top profile:
Next I rough shape the back bottom profile with a draw knife. I get close to the profile line. The draw knife hogs off wood fast - but this bubinga is certainly hard and dulls the draw knife pretty fast. I hit the sharpening stones and leather strop a couple times.
Next I shape the bottom profile with a table saw, 8-3 carving chisel, and file:
Now I revisit the back and finish the shaping process. At this time I use a rasp, spokeshave, and file. The trick is to shape the top edge, bottom edge, and ends. Then I simply work the middle so it all blends. No correct answer here:
The original Blacker House arm chair crest rail was made out of 12/4 wood. This crest rail is made out of 8/4 and so does not have the dramatic rearward sweep and concavity as the original. Nonetheless, I think it has a nice shape. This part of the chair will probably be touched the most and so it is important to have a nice tactile feel.
Next I cleanup the ends. I do not have an oscillating spindle sander. One is definitely on my wish list. Until then, I will use my drill press:
The back of the crest rail is finished!
While it is feasable to shape the front of the crest rail after glue-up, given that this wood is so hard I decide to remove as much wood as possible at this time, leaving the ends thick enough for clamps. Once again, the draw knife hogs off wood fast - with no dust!
Now its time for the last major glue-up! Upon clamping I had a moment of panic as the crest rail would not clamp tight to the rear posts. However, the clamping pressure eventually won the day. Given so many tenons on top (8 tenons total), I knew that clamping would be difficult. I left the small splat tenons rather loose for this reason. The center splat tenons were snug, however. Because I shaped the center of the splat front I no longer had a clamping edge which also made the whole process more precarious. That is the risk of shaping the front center before glue-up. With the Blacker House armchair re-production that I built awhile back I did not shape the center front before glue up - so I had a clamping edge which allowed me to get a third clamp in the center. But the mahogany for that chair is a whole lot softer than this bubinga and so shaping after glue-up was not all that difficult.
Another issue is that there was some side-to-side play with the crest rail vis-a-vis all the tenons. There was a risk that one of the splat tenons, which are housed, would get stuck on the housing and not insert into the housing - which almost happened for one of the tenons. I think it was that tenon that was preventing the crest rail to fully clamp tight to the rear posts until it finally slid into the housing.
Now its time to finish shaping the front and sides of the crest rail. I use a spoke shave, rasp, and file for this.
One more thing. I decided to go ahead and glue corner blocks to the two front corners of the seat:
Last step - ebony! I'll show that process in another post.
