All Plywood Is Not The Same
I’ve had a bit of time in the shop this week, so I went back to work on the storage boxes that sit inside my yet-to-be-built workbench. I know. It’s been almost six months and I’m still just building the boxes – managing editor duties are many.
After knocking out my dovetails, I laid out and cut the grooves for the sliding drawers I discussed in an earlier (much earlier) blog. (If you need to catch up, or to simply remember my plan, read this.) I used an Infinity Tools Thick-kerf, Flat-top table saw blade (1/4″ width) to make the grooves, registering the bottom edge of each drawer box side toward the fence with each pass of the four sides. I then used a router table to rabbet the rear edges for my backboards.
I applied glue to the dovetails and assembled the two boxes. As the glue dried I turned my attention to the plywood drawer bottoms. Before I had picked up a piece of Baltic birch plywood (BBP) from a local supplier, I checked my local home-center store for a usable plywood. I found 1/4″-thick plywood with one face sanded and sheets marked for underlay, but no BBP. I wanted BBP.
If you’re not aware of the differences between Baltic birch plywood and other “regular” plywood, the left-hand photo shows everything you need to know. (Click the photo to see it larger.) BBP, in the 1/4″ or 6mm thickness, is made up of five layers of birch veneer that is 1.3mm to 1.5mm in thickness. Also, there are no voids in the layers that could cause defects or lessen its structural integrity. Compare the BBP edge (Bottom) to that of the regular plywood (Top). The top piece has three layers with the center layer turned 90° to the faces. The extra two layers in the BBP increase stability (less warp), provide an edge that reacts more like hardwood, and it’s my opinion that Baltic birch plywood is a more consistent thickness across the piece. That makes this plywood a better choice for furniture, jigs and shop-grade cabinets.
At one time, Baltic birch plywood was available in only a 5′ x 5′ sheet. Today you can get other sizes such as 4′ x 8′ or even 5′ x 10′.
If you need plywood with a mahogany, walnut or birch face veneer, go to regular plywood. But if you are looking to veneer your own panels, or you need a stable plywood for jigs and other shop-made doodads, I suggest an nice sheet of BBP.
Read more about plywood in, “Choose the Right Plywood” by Robert W. Lang, or discover how to turn plywood into a couple of new jigs to make work at your table saw even better in the DVD “Table Saw Jigs & Fixtures.”