What's the difference between MDO and MDF?
I've seen you use MDF in projects and jigs many times in WOOD® magazine. Then I heard on a TV remodeling show about something called MDO. What's that?
—Greg Montano, North Wilkesboro, N.C.
Medium-density fiberboard (MDF) is manufactured from fine wood fibers and resin bonded together, Greg, and compressed into sheets to give it a smooth, flat surface. Medium-density overlay board (MDO) has a similar, smooth surface about 1⁄16 " thick on each face, bonded to a plywood core. Because MDO's faces contain more resin than MDF, MDO works well for exterior use, such as painted signs. Stronger than MDF, MDO weighs less and doesn't create a cloud of choking dust when you saw it. It also costs about a third more.
You'll find MDO at some home centers, but will have better luck at a lumberyard or hardwood retailer that sells sheet goods.