Now that I've worked out the coopered part of the piece and how it's going to be hung I need to work out what all the parts are going to be. As you can see, there will be a lot of end grain to side grain joints. I could go with just pocket hole screws - but as you can see, there are "set backs" everywhere - which are a little trickier to do with pocket holes - you need to make "spacers" to keep parts from moving since you can't clamp the parts being joined. I could go with dados - but they just make things complicated because the parts that fit into them need to have the dado depth added to their length. That just adds one more potnential source of error - and given my ability to screw up even an idiot proof method - I'll skip dados.
So what I'm looking for is something that's almost as quick as pocket hole screw joints but with some wiggle room.
Biscuits! I could go with biscuits. BUT - biscuits allow slippage - and keeping everything "square" is critical for this piece. Having the "frame" rack, even a little, will screw up the fit of the coopered components of this design - ANY gap WILL show.
Loose tenon mortise and tenon joints would do it. All the parts are their "visible length" - no need to add for the tenons. And unless you cut some slop in the mortises there's no alignment problems from slippage. Loose tenons would be perfect - EXCEPT for the fact that there are a TON of mortises to cut. Start counting the littleblack ovals in the illustation below. There are 28 mortises to cut - just for the coopered parts!
AND here's where the Festool DOMINO comes to the rescue. The DOMINO is A Solution Looking For Problems To Solve. This little gem enables you to cut mortises with the grain, acrossed the grain or into the grain with the speed of a biscuit cutter but with the precision of of a mortising machine or jig - WITHOUT ANY LAYOUT LINES - and - almost no Set Up time. If that isn't enough to make it worth its weight in gold - and it's almost that expensive - you can easily record the "set up" values for each set of mortises with just a few easy to repeat numbers. (go here if you want to learn more about this revolutionary new woodworking tool - note: I have no association with Festool and paid for this thing out of my own pocket)