Jointing a long board edge straight is mostly a matter of controlling the board as it crosses the cutterhead. The machine does the cutting, but your hands and support stands determine whether the last few inches stay straight or dip. That dip is often called snipe, though on a jointer it is usually caused by…
Why knife type matters on figured wood Curly maple, bird’s-eye maple, highly figured walnut, and other reversing-grain boards can tear out on a jointer even when the knives are sharp. The grain changes direction along the board, so a cut that works with the fibers in one spot may lift them in the next. Knife…
A jointer’s infeed and outfeed tables must be coplanar: both surfaces need to lie in the same plane, without one corner sitting high or low. If they are not, the jointer can produce tapered boards, concave faces, or boards that rock as they leave the cutterhead. The problem is often blamed on knives or fence…
Mortise-and-tenon joints depend on square, straight stock. A tenon can be cut accurately and still fit poorly if the board’s face is twisted, its edge is not square, or its thickness varies. A jointer prepares the reference surfaces that make the rest of the operation predictable. For most furniture work, the best choice is not…
What a Jointer Can—and Cannot—Do A jointer is useful for flattening a board with a mild cup, but only when the cup is shallow enough to control safely. The machine flattens one face and creates a straight reference edge. It does not reliably flatten badly warped stock, and it is not a replacement for a…
A jointer can flatten one face of a twisted board, but only if you keep the board stable while removing wood. The machine is not a magic twist remover: it cuts a flat surface wherever the board contacts the tables. If the stock rocks, the cutterhead transfers that movement into the finished face. The basic…
A jointer makes a flat face and a straight edge by removing material as the board passes over the cutterhead. The infeed table controls how much wood is removed. Set it too low and the cut becomes aggressive, rough, and difficult to control. Set it too high and the board may barely touch the knives,…
What a jointer does for cabinet parts A jointer makes one face of a board flat and one edge straight and square to that face. That reference edge is useful when sizing rails, stiles, face-frame stock, solid-wood edging, and other cabinet components on a table saw. A jointer does not make a board a precise…
Long edge-jointing passes expose every weakness in a jointer. A short, flexible fence can let the board drift; a small table can leave the trailing end unsupported; and a fence that is not square turns a straight edge into a tapered or twisted one. For furniture-length boards, fence stability matters at least as much as…
Wide boards are where a jointer’s table size matters most. A narrow 6-inch jointer may flatten an edge well, but it becomes awkward when you are jointing the face of a 10-, 12-, or 14-inch board. The board hangs off the sides, the cutterhead removes material unevenly, and keeping the workpiece stable becomes a wrestling…