Each machine does a completely different surfacing operation. A jointer flattens a face or straightens and squares an edge, and a planer thicknesses wood. Whether you need one, the other, or both can easily be answered by knowing how they work, what they do, and how much wood surface preparation you pay your lumberyard to do for you. And honestly, you probably could be a great woodworker without either machine. They are just time savers. Heck you could use hand planes! Ultimately, you need to convert your wood stock to usable pieces for your projects. A wood jointer and a planer will help you get there.
WWGOA Video: Jointer vs. Planer
What a jointer does and how it works
A jointer is used to make the face of a warped, twisted, or bowed board flat. After your boards are flat, then the jointer can be used to straighten and square edges (Guard removed for photo).
Jointers work this way
There’s an infeed table and an outfeed table. The tables are aligned in the same plane. A cutter head with knives is mounted between the tables, and its cutting circle (tops of the knives) is aligned flush with the outfeed table. The infeed table is lowered to a depth equal to the amount of wood you want to remove. Passing a board across the running machine (with guard in place) removes the wood, and the cut portion of the board is then supported on the outfeed table. A fence is used as a guide when flattening a face, and as a support when jointing board edges. The fence is adjustable for different angles, typically up to 45-degrees.
What a planer does and how it works
A planer is used to make a board that’s been jointed flat equal thickness from end-to-end. Mechanically it’s more complicated than a jointer, but functionally it’s simpler. A flattened board is placed on the planer table (bed) and pushed in. The machine’s feed roller grabs the board and pulls it through and past a rotating cutter head set above the bed, which removes wood. The distance the bed is set from the cutter head is the resulting thickness. All planers have limits to how much wood they can remove in one pass, so to achieve your finished thickness will likely require multiple passes. Want to see a planer in action? Check out this unique video that offers an inside view of a wood planer.
Different levels of lumberyard-produced surface preparation
Your lumberyard can do none, some, or all of your required surface preparation to the boards you purchase. The more they do, the more it costs, and the less control you have. You could take this to the extreme, give them a cut list, have them size all the pieces, but you’d go broke and have no fun woodworking. I’ll start by telling you how both machines are used to surface rough lumber, and then give three more scenarios where your lumberyard does increasingly more of the work for you.
Remember, it’s not Jointer Planer. A jointer can be used to make a board’s face and edge straight and true. A planer makes your boards uniform in thickness, with two parallel faces. The operations aren’t interchangeable between the two machines.
Owning both machines gives you the greatest control over the flatness and smoothness of the wood you use in your projects. My jointer is a monster at 12-in. wide and 84-in. long. It’s really nice for flattening long and wide boards, but may be overkill if your projects will be small. My planer is 13-in. wide making it the perfect companion to my wide jointer.
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