Can you plane plywood?

Is it okay to run plywood through a planer? I made door panels out of plywood that had only one good face. To get two good faces without adding thickness, I planed some material off the backs of two pieces, and then laminated them. It worked, but is it recommended?
—Tony Stich, Gulfport, Miss.

You can do it, Tony, but you may have already discovered two good reasons to not do it. First, the glue holding the plies together dulls knives quickly. (The same goes for other glue-laden sheet goods, such as MDF or particleboard.) And planing across the grain of a ply creates long stringy fibers rather than tiny chips, which can clog the planer's dust port. In the future, should you need plywood with two good faces, we suggest laminating pieces of thinner plywood or applying veneer over the "bad" face.

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