Replies

1. 
   joinerswork | Jan 01, 2010 11:46am | #1

   Frosty,

   The back rail could be either mortise and tenon joined to the stiles, with a large haunch (1" or more) on the top end of the stile; or it might be attached with a sliding dovetail joint, the socket worked into the face of the rail, the male member worked onto the rear face of the stile. The dovetail joint will be stronger if the rail extends at least slightly beyond the stile.

   The armrest could be tenoned into, or thru the stile and wedged from the rear, or pinned from the side, at the top of the stile, above where the mortise for the back rail ends (the reason for that large haunch). Or you could dovetail it into a shallow socket (1/2" or so) in the outside of the stile. Easier, and traditional, is to fit the armrest to the stile as a butt joint, or in a very shallow (1/8") recess (like a dado), and fix it in place with a screw or (3/16") bolt, the nut bedded in the armrest like a tiny bedbolt, driven thru the rear of the stile, and covered with a face grain plug.

   The tricky part is to size the joinery so as to impart "enough" strength to the joint, without losing too much wood and impairing the integrity of the members themselves.

   Ray

1. 
   Jfrostjr | Jan 03, 2010 10:44am | #3

   Thanks to both of you for your suggestions. As I hoped a fresh approach popped up: I had forgotten to consider a sliding dovetail.

   There are three items that are not obvious from the very 'quick and dirty' prototype: the crest rail is mounted upside down, the center stile is to be tenoned into the crest rail and the back is canted to the rear about 8*.

   This latter fact creates an assembly issue. Therefore, I will make a more accurate prototype as follows:

   Assemble and install the arm/stile unit. The arm will be mortised into the stile and pinned, in contrasting wood, after the unit is installed into the seat (if this is done before the glue sets I should be able to fit the parts into the canted rear mortise and the vertical front mortise);

   Then install the crest rail/center stile unit by sliding it down a dovetail at the 8* angle. As the stiles are wider than the arms, I should be able to place the male portion of the dovetail on the stile.

   Any comments?

1. 
   joinerswork | Jan 03, 2010 11:30am | #4

   Frosty,
   I'd recommend
   Frosty,

   I'd recommend assembling the back to the stiles first, then add each arm. If the arm/rear stile assemblies are at all out of parallel, the dovetail joint will be a headache to assemble.

   If the laminated arm rest cannot be sprung enough to allow for assembly, you can always taper the front of the seat tenon and the top of the back tenon slightly to let you rock the arm into place.

   Ray

1. 
   Jfrostjr | Jan 03, 2010 12:36pm | #5

   GOOD point!

   My comment about "sliding" the crest rail down on the dovetail sounds laughable, now that I think about it.

   Many thanks,

   Jerry

2. 
   gdblake | Jan 01, 2010 12:19pm | #2

   I don't understand why you
   I don't understand why you would have the horizonal back support behind the rails as shown on the prototype. If you are looking for easy construction I would notch the support rails to mount the back support to the front side of the rails and then attach the arm rests via a wedged mortice and tenon to hold everything together at the sides. Another option is to use sliding dovetails to attach the back rest to the support rails and still use a wedged mortice and tenon to attach the arm rests.

   gdblake