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    How to Use a Jointer

    You won’t need a jointer to get started woodworking. Just buy presurfaced lumber (that has already been milled straight and smooth) at home centers and lumberyards. Look for boards that aren’t warped or bowed, and make sure they have been surfaced on the two faces and at least one edge.

    But roughsawn lumber is cheaper, and is available from hardwood dealers in much wider variety of wood species, so you will want a jointer at some point (and a planer; more on that later).

    Where it used to take a skilled craftsman a half hour or so to flatten a board with a handplane, a jointer can do it in a few quick passes.

    Don’t confuse it with a planer. A jointer is the only way to get the face of a board flat and straight. Then that face rides the bed of a planer, which flattens the opposite face and brings it to uniform thickness.


    That flat face stays face-down for the next step, which is running the board through the planer to smooth the other side and bring the board to an even thickness.

    You need both machines to turn rough lumber into flat, straight workpieces, and you need flat, straight workpieces to do good work.

    The jointer also straightens and squares one edge of a board before you head to the bandsaw or tablesaw to cut it to final width.

    The jointer straightens the edges of boards too. Be sure the fence is square to the table, and keep the workpiece pressed against it, so the workpiece ends up square, too. Photo: Asa Christiana

    As it is with most woodworking machines, setup is pretty important on the jointer. The key is to adjust the outfeed table perfectly level with the knives. That way the board will pass over the cutterhead and glide flat and smooth onto the outfeed table.

    The board moves right to left, from the infeed table, over the cutterhead, and onto the outfeed table. Note how the grain is running “downhill” for smoothest results.

    The infeed table determines the depth of cut. Don’t try to take off more than 1/16 in. at a time. The fence also needs to be square to the tables for jointing the edges of boards.

    To avoid tearout, you should be aware of the grain direction on the board, and run it over the jointer with the grain running downhill.

    The right technique for jointing the face of a board is to put the cupped or bowed face down.

    Jointing a Cupped Board

    The cupped or bowed side of the board should go face down. Keep jointing (making multiple passes) the board until that lower face is flat.

    Concentrate your pressure on the infeed table until the board is about halfway across the cutterhead. Then you transition your pressure onto the outfeed side.

    Afterward, take a look at the face and see if it needs another pass.

    Safety note: Use push pads and push sticks to keep your hands away from the cutterhead, especially when jointing the faces of boards. And don’t try to joint a board that is less than 1/4-in. thick.

    Drawings by Jim Richey