Well getting the bottom flat and dimensioned turned out to be way more work than I had expected. I guess my less than stellar work at school on the "perfect board" exercise to hand plane a board perfectly flat came back to haunt me on this one!
One of the two boards I used was reasonably well behaved, it flattened readily and stayed flat. The other, not so much. Anyways, I got them as close as I could/dared on the machines, then glued them up and handplaned them down to thickness.
I was annoyed at myself for a long time because of my mistake on the length of the two original boards I had for the bottom and the fact that I liked their grain pattern better than the pattern on these two boards I had to go with. In the end I am happy with these though, the grain pattern turned out to be acceptable. I wish it were a bit straighter, but I didn't have much choice.
Tearout while planing was a challenge with the contrast between the hardness of the earlywood and latewood on the Monterrey cypress, as well as the grain direction changes, but my Krenov style plane really saved me.
Now the next step will be to get some grooves routed in the bottom and part way up the sides for a couple of dividers. Since it is supposed to be a tool box, I'll set the two dividers something like this so a plane will go in each compartment. Eventually(!) I will make a tray to fit on top of the dividers. Really, I will, I already have some wood selected for it.
5 hours ago