8 Use of the Jointer
Safety rules
As the cutterhead is exposed in use, the jointer must be used with caution and only by trained operators. Observe the following safety guidelines for the jointer.
- Never run your hands directly over the cutterhead while on the surface of a workpiece. Lift and place them, or use a push block.
- Do not place your hands within 150 mm or 6″ of the cutterhead at any time.
- Do not place your hands within 150 mm or 6″ of the leading edge of the board.
- Use a push block or stick at the end of the cut, especially when face jointing.
- Do not joint thin stock (less than 12 mm or 1/2″).
- Do not joint material that is shorter than 300 mm or 12″.
- Do not edge joint stock that is less than 20 mm / 3/4″ wide, and use a push block designed for narrow stock.
- Only remove the spring loaded guard for rabbeting operations, and replace it immediately after use.
- Do not joint excessively knotty or defective stock. It could break apart while jointing.
- Do not joint end grain.
- Do not pull a workpiece back out of the machine, it can grab and kick back.
- Jointing a heavy cut increases the potential for kickback, always check the depth of cut before starting, and reduce the depth of cut for wider stock or dense hardwood.
- Feed the work at a rate that it does not reduce the speed of the cutterhead.
- Reset the depth of cut to 1 mm / 1/32″ – 1/16″ after using the jointer.
- Do not wear loose fitting clothing or jewelry. It can be become tangled and pull you into the cutterhead.
- Follow all general machine safety rules.
Stock preparation
Material to be jointed should first be cut to rough length and rough width. Where rough stock is quite bowed or cupped, cutting it to the smallest size possible while still leaving a machining allowance will help to preserve thickness and width. Smaller pieces to be jointed should be left in multiple lengths to safely machine, and cut to size after jointing and planing. With all pieces to be jointed, ensure the ends have been trimmed free of defects such as splits or checks. This also ensures staples and paint are removed prior to machining. Do not joint plywood as the adhesive is very abrasive and excessively dulls the knives. Never place stock on the floor where it can pick up grit and small particles that will dull and damage the tooling.
Machine sequence
The jointer is the first machine used in bringing rough stock to an accurate piece, ready for joinery or further machining. Surfacing four sides, or S4S is a common step in almost all solid lumber machining. The steps should be completed in this order:
- Joint a face side.
- Joint an edge square to the face side.
- Plane to final thickness (using the thickness planer).
- Rip or plane to final width (using the table saw or thickness planer).
Grain orientation
When selecting the direction of feed, grain orientation must be checked to ensure the wood fibres are smoothly sheared and not lifted up. The cutterhead rotates toward the operator, there