Green & Green Blacker House armchair - part II

The crest rail is a beautifully sculpted piece that requires 12/4 or 16/4 stock to make (I need 3" thickness after milling).   At school I had left the crest rail as a big rectangular block.  I had cut the mortises in the bottom of the crest rail and fitted the crest rail to the post and splat tenons (8 mortises total).

I decided that the first task should be to shape the back of the crest rail.  I need to leave the front mostly unshaped so there is enough meat in the wood for clamps during glue-up.  Because the front of the crest rail is convex and curves away from the front of the chair, shaping the front should not be too difficult after glue-up.  However, the back is concave and therefore will be more difficult to shape after glue-up as tools and hands will have a tendency to hit the back of the chair rails and splats.  I find shaping concave surfaces more difficult than convex surfaces.

My life size design drawing has a plan (top) view, front view and side view of the chair.  The plan view tells me the shape of the top of the crest rail.  The side view gives me the profile of the back at both the center and at each end.  I made cardboard templates as guides during the shaping.  Once I had the middle and ends shaped I could then shape and blend the spaces between the middle and ends to finalize the entire back.

I shaped the top curve of the crest first with a bandsaw and spokeshave and then proceeded to shape the back starting with a carving chisel (to hog off wood) and a combination of rasp, spokeshave and finally a curved card scrape.

The next photo shows the back of the crest rail after the card scraper.  The edges are still sharp.  I will ease and round over sharp edges later after glue-up.  Although this photo does not show it, I will bandsaw the front of the crest rail to establish the bottom curve of the front.  This will leave enough wood at the top for clamps.