The last time I wedged through tenons was about 3 yrs ago, on the round (2" diameter) shaving horse legs. For my latest project, I had to research w hich way to orient the wedges into the end grain.... along or across the gr ain? I didn't think to look at the shaving horse legs, to see how I did i t, there. Common sense told me across the grain, but I simply didn't remem ber which way is appropriate.
Of the several/many sites, I found this one.....
.... which states - Re Structural Considerations: " There are a few points to remember, crucially the grain orientation; get this wrong and you will split the leg, top or rail you are going into. Alwa ys make the wedges spread at 90 degrees to the grain direction, so that the pressure of the wedge is against the end grain and NOT with the grain."
I'm making 5 cypress chairs, thick bulky stock to begin with, but I'll carv e most of the bulk/thickness away. Most of the work is with hand tools, so the tenons are not perfectly fitting the mortises. The wedging will, hope fully, compensate the small fit-differences, besides further securing the j oints.
The legs (and mortises) are angled about 6° on two axis, side-to-side and front-to-back. The leg's stock is 4"X4"; the tenons are about 2"X2"X2 "; the seat stock is fully 2" thick, or slightly more, all salvaged lumber. The seats and legs will be carved/contoured, so much of this bulk will be reduced, also. Cypress is a soft wood, so the extra bulk of the joinery w ill help compensate for the lack of the wood's strength. The chairs will likely still be a good bit heavier, than normal chairs, despite removing mu ch of the bulk.
Most of the contoured backrest support "slats" (styles?) are roughly carved , as are the backrests' top rails. Take my word for it, this drawknife/sh aving horse work is a lot tougher when working on dried/seasoned lumber, th an on green lumber!!!! The stock was split with a froe, somewhat formed w ith a hatchet, then further formed with the drawknife and scorp. I'll fine
-tune their finished shape/contour, later, as per their individual custom i nstall/fit (mortise-tenon). Pics- see below link.
I still need to make the angled back legs/backrest support. I'll roughly profile-cut the back legs using the *bandsaw, before further carving to a m ore refined shape.
*I think those Youtube videos, on the ease of crowning bandsaw tires, are l ies. A few days, each for the past few weeks, little by little, I've been sanding the new tires on my 20" top wheel and it's taking a heck of a lot l onger, than the 20 minutes, those Youtube videos claim it takes. I won't b e able to form/cut the back legs until the tire-crowning is finished.Mortise-tenon pics. In the background (top right) of the first MT pic, you can see a few contoured backrest support "slats" (styles?). First 5 pics -
Since the leg tenons are larger than "normal", I'll probably use 2 wedges p er tenon. I'll test install a few, on some scrap, to make sure the tenons don't split.
Sonny