When I first started working on my Roubo workbench, I was given the advice to buy 2×12 lumber, rip the sides off to use to laminate the top, and then toss the pith section from the middle into the scrap bin. Needless to say, I ended up with a lot of pith scrap. The idea as I understood it is that the pith section is the least stable and to have it used in the bench top (or other critical parts of the bench) could lead the problems later.
Pith scrap end grain:
I did use some of the left over pith scraps on “non-essential” parts of the bench. For instance, I sawed and planed some down to use as the cleats to hold the shelf at the bottom of my bench. Even with that, I was still left with a bunch of scraps roughly 2” x 3” and ranging between 4’ to 8’ in length. When I started building this cabinet, I got the wild idea to rip and resaw some of these scraps to edge joint in order to create the back of the cabinet.
My line of thinking was this: considering that I would be cutting them so that there wouldn’t be any more fully circular end grain on any one piece AND the fact that they were going to be so thin in their final size (3/8”), that it shouldn’t be that much of a problem from a stability standpoint. Of course, this is all supposition on my part and a bit of a wood movement experiment.
So, I grabbed my trusty (cheap $10, plastic-handled) Stanley rip panel saw and got to work. I cut them a little more than 1/2” thick at first, because I expected them to move quite a bit (and some of them did). This would leave enough for me to be able to hand plane them down to 3/8” final thickness.
Here are some of the pieces sitting over night to allow them to move:
The first few edge-jointed pieces clamped up
While the back was being clamped / glued up in stages (I’m too much of a chicken to edge glue more than a few pieces at a time :) ), I made some templates with scrap paper to begin to play with the layout of the tools. This also allowed me to get an idea of how wide the cabinet would have to be in order to accommodate the tools I wanted to store; remember, I was working without a plan here.