Adela Christensen Jointers August 14th, 2018 - 05:20:07
Jointer size is most commonly determined by the full width of the knives (knives). A 6" jointer makes a maximum 6"-wide cut. An 8" jointer makes a maximum 8" cut and so on. It would be rare to use the entire width of even a 6" knife set at once, so the real advantage of wide knives is that you can move the fence to use a sharper place on the knife when the knife becomes dull. The wider your knives, the more use you will get out of them before it is time to re-sharpen. I usually start with a sharp knife set and the fence all the way to the right end of the cutter head and move the fence, in increments, a bit wider than the maximum board thicknesses, to the left until the knives are all used up.
Always cut with the grain of the wood and never against. Hold the stock with your left hand against the fence and push it with your right. This may take a while since you are only shaving tiny pieces. Be patient and take your time.
The jointer is a high-speed, stationary power tool. It has a table consisting of two adjustable surfaces: an infeed and an outfeed. Between these two horizontal surfaces (under a safety guard) is an opening below which are razor-sharp knives that rotate at a high speed. By adjusting the height of the infeed surface the knives will shave wood away from a board fed through the jointer.
While the jointer can be used as a planer for small pieces of lumber, the principal function of this woodworking machine is to put a straight, smooth, level edge or edges on a board in preparation for edge-to-edge glue-up. Rabbeting can be accomplished on some jointers but I prefer to use the table saw for this task. Chamfering, or making angled cuts, can be performed by tilting the fence.
A wood jointer can remove these imperfections very quickly usually in less than a minute if not seconds. Then when a piece of lumber is laid next to another piece they fit together smoothly and precisely. A tight 'joint' is formed. Hence the origin of the word 'jointer' a tool that can form a tight joint. The carpenters of old could only marvel at what a modern wood jointer can do in a few seconds!