Green & Green Blacker House armchair - part III

To arms!

As I suspected, the arms for this chair is a non-trivial exercise!  This chair has the arms mortised to the front legs.  At the rear posts the arms are housed in a notch and secured with a screw.  The screw hole is covered with a large ebony plug on the inside of the rear post.  The fact that the front legs and rear posts are parallelograms and not square complicates matters, not to mention the various curves, slopes, tapers, etc.

There are probably a couple ways to construct and attach the arm.  A plywood template could be used to fine tune the precise location of the front mortise vis-a-vis the notch at the rear.  However, I decided to divide and conquer.  The front of the arm is stepped which lends itself to such an approach. 

Phase I:  I cut out a stub piece of wood from the arm blank.  Being from the same arm blank, the stub will have the same grain pattern as the rest of the arm above.  I then cut a mortise and a taper (as the arm slopes downwards towards the back).  I tapered the bottom of the stub so the entire stub will slope downwards in the same direction as the arm above and therefore have the same grain direction.

 

 

Phase II:  With the stub fitted, I can then fit the main body of the arm to the notch in the rear post.  Once that is fitted, I will simply surface glue the top of the arm to the stub.  I will leave a lot of extra wood (or slop) up front so I do not need to worry about an exact fit over the stub - no fussing. 

FIrst I milled the arm top to final thickness.  Then I spent a lot of time laying out my lines to determine how far I want to cut the bottom taper in the arm (making sure I leave enough slop up front).  I also layed out the lines for fitting the back of the arm into the notch in the rear post.  I checked and double checked my layout lines, being cautious of the fact that the front leg and rear post are parallelograms and that the angles on the rear post are slightly different due to the fact that I had hand planed parts of the rear post (just to make life interesting, I suspect).

I cut the bottom taper on the bandsaw then hand planed to my lines.

Next I cut a notch in the rear of the arm to fit the angle of the rear post. 

Next step is to clamp the arm pieces in place and then scribe with a knife the exact location of the notch in the rear post.

Once the notches are scribed, I then used a chisel and my dremel router to hog out the waste.  I went 1/8" deep - hope this is not too deep since during glue-up the arm needs to fit the front tenon and pop into the rear notch simultaneously.

A bit of promotion here:  For the dremel I'm using a plunge router base from Stewart MacDonald.  This base is very well made and what is great is that it has an inlet to attach a small air pump and hose.  This clears out the dust during routing - a wonderful feature.  I consider my dremel and this base and accessories mandatory in my shop.  I also bought a set of 5 downcut carbide spiral bits - from 1/32" to 1/8".  They work great.

I think I'll call this post done for now.  I'll finish the arm in another posting.

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.

Green & Green Blacker House armchair - part I

Hello fellow woodworkers.

I thought I'd share my experiences building what I believe is one of the most beautiful chairs ever built.  Here is a link to a photo of one of the originals:

http://www.gamblehouse.org/nnb/object/5192.html

I started this project as my last project as a student at North Bennet Street School in Boston MA.  I had finished much of the basic construction at the school.  The major tasks remaining upon graduation in June 2009 was the shaping of the crest rail, the arms, as well as the sundry decorative elements (such as ebony plugs, etc).  I was lucky to have fantastic instructors at the school.  I was also lucky to get some useful design guidance from a fantastic former instructor who had built a couple of these chairs herself.

Well, that was in June 2009.  Almost 2 years later I have started working on the chair again.  In the interim my wife and I bought a house in Ashland, Oregon.  The house search, working on the house and setting up shop swallowed up the rest of 2009 as well as most of 2010.  I am finally back in the shop!  The shop lacks storage and a workbench.  Those projects will come later.  I want to finish this chair!

Here is a photo of the chair at the school just before I left Boston.  The legs and rails are all glued up.  The various splats and crest rail are not glued up.  Not sure if this is the best procedure, but I wanted the chair to be assembled as much as possible as I knew it would be in storage for some time.

  Being away from a project for 2 years requires a certain mental context shift and adjustment (namely, what the hell do I do now?).   Well, just dive in and start making mistakes and hope these early mistakes are only minor!