Step 11: Assembly
Finally! Time to start screwing everything together. I must have been a little worried about glue setting while I was futzing with the camera because I didn't really take any pictures. Things are pretty simple at this point, because each box has already been assembled and the holes are drilled. If there were going to be any issues with fit they would have reared their head before this point.
Before pulling out the glue I get my 'mise en place'. I get a bucket of water and a rag to take care of cleaning up glue squeeze out. I make sure I've got my screws at hand, along with my driver and a fresh battery. I get my biscuits, and a small brush to get the glue down into the slots. Then I get to gluing.
I took each stack and set them on end with a clamp to hold them together, then ran a bead of glue down the center of each edge. After that I'd pick up my brush and spread the glue out, making sure I got down into each biscuit slot. Then each slot would get a biscuit.
Next I'd pull off the clamps and fan the pieces out like in the second photo and repeat the gluing and spreading process. No second round of biscuits, of course.
Then it's just a case of reassembling the boxes, making sure that you follow your notation and get the correct corners lined up. I made sure each piece was sitting flat on the table, then slip my shim clamps into place and throw the final clamp through the handholds.
All that's left to do at that point is to drive all the screws. Be careful not to overtorque them. Once the glue in the joint squeezes out you know it's snug. Get the rag and clean up all the glue squeeze out. If you don't take care of it now, you'll have to sand it off later.
Don't be lazy and skip the glue step. It's doing as much, if not more, of holding the box together than the screws. Screwing into end grain like we're doing actually isn't a great joint. The screws are more to keep the joint tightly clamped than anything, since trying to clamp non-parallel surfaces is a pain. Don't skip the glue.