Ready to go,... wait, ONE MORE TEST!

Last night, I finished sanding all my wood parts to 400 grit.  I am ready to apply finish.

I went to sleep knowing that I can not make this any better.

But I woke at about 6, with a start; will the arms and back really work???   These are single pieces of wood sticking up, doing the work normally done by at least two vertical pieces on every chair I have ever seen.  I have a good sense of the strength of materials, but the little nub I was able to snap off so easily the other day, made me very nervous about the brittleness of this wood.  As I dressed (in my truck outside the shop, where I have been staying most nights, with visits to my friends John and MK  every few days) I already started contemplating a test of the arm and how I might redesign it if it proved inadequate.  I imagined a connection tieing the arm to the back support... but ugh, I don't want to have to do this.

Now in the shop, I found the old arm I had made when I started making the pieces, and secured it in the vise in a position where I could subject the weakest section to the greatest leverage.  I leaned lightly and shook the upright arm.  Then I threw my weight into it, not with all my strength as in a football tackle, but a good sturdy body thunk, well more than anything I can imagine might happen in the chair's daily use.  It held, much to my relief.  Ok, then I replicated the two small "finger" buttresses that will be on the final piece, and I joined them to the top of the arm, and then attached my plywood mock-up armrest using a biscuit joiner and glue, as I will on the final piece.  After just an hour of clamping time, I could not stand to wait any longer, so I put the arm back in the vice, and loaded the arm rest with my toolbox, which has become my default testing weight.  Again to my relief, it held.  And the backrest?  You may remember I have already installed a bolt through the weak point, so I'm pretty confident in that member.

Only a man who cares has doubt.  (proverb)

Will my mortise and tenon joints attaching the arms and back be sufficient?  Am I using the best glue, the yellow woodworking glue?  Should I use Epoxy, which is better able to fill voids as I have around my not so perfect m&t joinery?  Or the new polyurethane glues, like Gorilla Glue, which can expand to fill voids?  Each of these have problems, too; the epoxy is runny and messy and very hard to clean off if it gets on an exposed surface, and the polyurethane glues lose strength where they have room to expand, and the squeeze out from the expansion can make a mess too.  I looked over my joints again.  They're not so bad.  One could use a touch up.  I think I'll do that and stay the course with the old reliable yellow glue.

On to pre-finishing and prep for glue up.