Stock Inspection and Requirements
Here are some rules to follow when choos- ing, jointing, and planing stock on a jointer or thickness planer:
•DO NOT joint or surface plane stock that contains knots. Injury to the operator or damage to the workpiece can occur if the knots become dislodged during the cutting operation.
•DO NOT joint or surface plane against the grain direction. Cutting against the grain increases the likelihood of stock kickback, as well as
•Jointing and surface planing with the grain produces a better finish and is safer for the operator. Cutting with the grain is described as feeding the stock so the grain points down and toward you on the jointer (Figure 28) or away from you on the planer (Figure 29), as viewed from the edge.
Note: If the grain changes direction along the edge of the board, decrease the cutting depth and make additional passes.
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Figure 28. Correct and incorrect grain alignment
to cutterhead (jointer).
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Figure 29. Correct and incorrect grain alignment
to cutterhead (planer).
•Remove foreign objects from the stock. Make sure that any stock you process with the jointer/planer is clean and free of any dirt, nails, staples, tiny rocks or any other foreign objects, which if they hit the knives or inserts and are drawn into the dust collector, may cause a fire hazard. The particles may also damage the knives/inserts. Wood stacked on a concrete floor can have small pieces of stone or concrete pressed into the surface.
•Only process natural wood fiber through your jointer/planer. Never joint MDF, par- ticle board, plywood, laminates or other syn- thetically made materials.
•Make sure all stock is sufficiently dried before jointing or planing. Wood with a moisture content over 20% will cause unnec- essary wear on the knives/inserts and poor cutting results. Excess moisture can also hasten rust and corrosion.
•Scrape all glue off of boards before plan- ing.
•Keep your work area clear.
Jointer Specific Rules:
•Make sure your workpiece exceeds the minimum dimension requirements (Figures 30 & 31) before edge jointing or surface planing, or it may break or kick back during the operation!