Simple jig for planing the sides of finished boxes
My goal in woodworking is not to make jigs, so my favorite fixtures are the simplest ones. This one has the highest simplicity-to-value ratio I know.
As I’ve blogged before, I’m hard at work on 4 stackable tansu dresser pieces. They have big tab joints at the corners. Those are pretty hard to get dead flush during glue-up, so there is some serious planing to do afterward. Trouble is, it would be impossible to plane the sides with the cases clamped atop my bench. I’d have to work 7 feet in the air! And there’d be too much flex in the boxes anyway.
So I turned to a trick I learned from Mark Edmundson, a frequent FWW author from Sandpoint, Idaho, who probably learned the trick from some guy before him. You just clamp a board to your benchtop, which hangs over the floor, fits into the box, and supports the surface you are planing. Of course, it works on any scale, for planing and fitting drawer sides, for example.
I used a big piece of cheap CDX plywood, clamped between dogs on my bench, and sized to fit into the case. It was a bit concave (aren’t they all), so I put that side up, and just tapped the plywood down at the dogs to flatten it. The inside of the case butted against one end, and it worked great for planing an entire side of the case at a time, joints, pegs, and all. Edmundson did it a different way, attaching a cleat below that he grabbed in the vise. The thick cleat would also serve to flatten the board, but my way worked fine, sans cleat.
Another cool thing, as you can see, is that if you have internal dividers in the case, you can just notch the support board to accommodate them.
Bear in mind, you do need a sharp handplane so you don’t have to bear down too much on the plywood. You could always double it up, though, if need be, screwing two pieces together.
The support board holds the case in mid-air, at a perfect planing height.
My twin-screw vise has two dogs spaced widely apart, locking the support board very solidly. Another option is to attach a thick cleat to the underside, and grab that in the vise.
When you have dividers in the way, you just notch the support board. I did that with two tablesaw cuts, with a big hole at the end to free the waste piece.
That let me put one of the other case pieces on its side for planing. For the first case piece (a chest of drawers), I just did extra notches.