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...or "Who the Hell Free-hands This???"

A while back I posted Part 1 to this, covering the mortise block, but stuff came up (chores, pandemic, filing for unemployment...). All two of you showed interest, but I'm all about follow-through, so here's Part 2. The adventure started as the next step in my own learning curriculum and wanting to rely totally on the box for acoustic response. I decided I could just about handle making a mortise and tenon join with a bolt over a dovetail, and so here we are. Same as the first, I'' do this one as a photo journal with concise explanation and tips each step of the way.

Goodbye thru-neck aka 'the bris stage'

This was a special feeling - kinda like when you jump out of the plane and really hope that chute works. Okay, dramatic effect, but I think you feel me. Up to this point I treat it as a thru-neck so that I've got something to clamp in the vise while shaping the neck. I should note that I leave about 1/32" of extra width for chisel fitting the tenon to the mortise later.

Shaping the tenon

Like I said in the opening, around this point I really started questioning the wisdom of not building that tenon routing jig, but I have zero storage space left in our little condo, so... I mapped out the final shape, skipped the coffee that day, grabbed my freshly honed chisel and away we go. It's worth noting that I cut in a little 'relief' all around the tenon join to the heel to 'cope' the fit to the box nice and flush.

Final shaping

ONLY once I've chiseled down til half the pencil line thickness is gone do I break out the sandpaper. It's alwasy the last resort as far as I'm concerned. It's critical the tenon makes contact with the mortise as full as possible, and that kind of precision is only possible with cutting tools.   

Final fitting the heel

Same as any stacked heel, this is a neat trick for eliminating any gap in the join. Trap thin strip of 220 grit paper between the both sides of the heel and the box and pull back and down smoothly and evenly, checking both sides carefully. The pictures tell the story...

Drilling for the bolt

And this, ladies and gentlemen, is where I really started re-evaluating life choices. I dry-fit the tenon to the mortise to mark the hole position for the bolt, but without a jig to align the drill, I knew I was going to have to 'fly by wire'. At this point I seriously thought about making my fortune by inventing a miniature drill that could fit into tiny spaces like cigar boxes. They don't already make one, do they? Don't tell me now anyway... I finally decided to use a self tapping screw to drill the hole thinking I could go nice and slow and control the straight line approach; and I DID!  

Final check with the actual bolt

Setting up the cross nut dowel

You'll be glad if you've stuck with it this far, because this is where the crazy really kicks in. We're using a bolt, so we need a nut right? (Okay, watch the jokes.) Here, a dowel nut is inserted across the tenon to receive the bolt through the mortise. The fun part is, that dowel has to be perfectly squared up at all 180 degrees - think about that neck aligning perfectly square to the box left and right and with a 2 degree set-back angle... Right. :-)

As you can see, I carried the outer and center lines of the bolt hole to the sides of the tenon, making sure to keep the lines square to the vertical line of the tenon. Next, I clamped down the neck, clamped my drill in a vice square to the tenon, and drilled a pilot hole just to make sure the hole lined up from one side to the other. Hey, I'm not... never mind.

Woo-HOO!!!

Drilling the dowel nut hole

With the pilot hole done and everything coming up Milhouse, this is where you do the "Uh-huh! That's right! Who's the Man." dance. No, there's no picture of that.

My biggest regret at this stage was not drilling that hole BEFORE I cut the thru-neck down past the outer surface of the heel. You can see how tight the bit was to the heel and it's nothing short of a miracle that I didn't nick the edge of the heel and ruin a perfectly flush fit. Then again, there was no way I was going to trust that that measurement would carry through the whole process to this point, so it's pretty much 'pick your poison'.

Holy sh*t! I can't believe i... I mean, 'Just like I planned it.' :-)

Joined!

Having gotten through it, if you find that the tenon fit is a bit loose to the mortise in any direction, you can lightly dampen the loose spots on the tenon - the wood will swell with the moisture and 'Voila' a nice, tight fit - a trick I learned from watching Japanese joinery (which is some of the best quality time you'll spend on Youtube).

The final build & thoughts

Would I do it again? Oh, you betcha! If you've worked with these boxes, you know they're beefy. The top is 11mm / about 7/16" thick, routed for the pickup, no sound hole, and it's easily the loudest, most projecting build I've done. (The first strings-on acoustic test is posted here on the Nation.) Freeing up the box to respond fully to the strings let's it be exactly what it's intended to be: a sound box. Now, to find space for that jig...

Happy building and stay safe ot there!