How to use a Jointer

Summary

This video offers an in-depth guide to using a jointer effectively, focusing on achieving perfectly flat and square boards. It explains the key parts of a jointer, proper setup, and essential wood terminology, including face, edge, bow, crook, cup, and twist. The instructor emphasizes understanding the forces at play, proper grain direction, and the importance of light, controlled pressure when jointing. Techniques for handling bowed or twisted boards, edge jointing, and using push sticks safely are demonstrated. Viewers will gain practical tips to improve accuracy, maintain safety, and master the finesse required for precise jointer work.

Takeaways

• 🪚 A jointer has four main components: infeed table, outfeed table, fence, and cutter head, all critical for proper operation.
• ⚖️ Ensure the infeed and outfeed tables are coplanar and parallel before jointing for accurate results.
• 🔪 Knives should be set at the same height as the outfeed table or slightly higher, never lower.
• 📏 The fence must be adjusted to 90° to provide a proper reference for edge jointing.
• 🌳 Always feed wood in the same direction as the cutter head rotation to minimize tear-out and achieve a smoother cut.
• ⬇️ Apply mostly horizontal force when jointing, with minimal downward pressure to counteract the knives.
• 🌀 Place the concave side of bowed boards down to maximize stability and contact with the table.
• 📐 Edge jointing requires keeping the board flat against the fence, with center-applied force to avoid lifting or twisting.
• 🛡️ Use push sticks designed to apply horizontal force and keep hands safely away from the cutter head; avoid foam push pads.
• 📌 Light, steady, and controlled movements are key to both safety and achieving a flat, square surface.
• 📏 Planing the opposite face before edge jointing creates a reliable reference surface for accurate parallel edges.
• 🔄 Understanding wood warping (bow, crook, cup, twist) is essential for properly orienting boards during jointing.

Q & A

What are the four main parts of a jointer?

The four main parts of a jointer are the infeed table, the outfeed table, the fence, and the cutter head.

Why is it important for the infeed and outfeed tables to be coplanar?

The infeed and outfeed tables need to be coplanar to ensure that the material is supported correctly and stays straight as it passes over the cutter head. If they are not coplanar, the cut may be uneven or the board may lift.

How should the knives on a jointer be set relative to the outfeed table?

The knives should be set at the same height as the outfeed table or slightly higher (within 0.001 inches). They should never be lower than the outfeed table, as this can result in uneven cuts.

What is the recommended grain direction when jointing a board?

The grain should move clockwise from the top to the bottom of the board as it passes over the jointer cutter head. Going with the grain ensures smoother cuts and reduces tear-out.

What is the proper orientation for a bowed board when jointing?

For a bowed board, the concave side should be down on the jointer table. This provides two points of contact and stabilizes the board during the cut.

Why should minimal downward force be applied when using a jointer?

Minimal downward force is needed because the cutter head pushes up on the board. Excessive downward pressure can distort the board, causing it to spring back and preventing a flat surface.

What are the problems with using foam push sticks when jointing?

Foam push sticks require too much downward force to move the board, which can destabilize it and increase the risk of inaccurate cuts. A proper push stick should transfer force horizontally without pressing down.

Why is it important to flatten one face of a board before edge jointing?

Flattening one face first provides a stable reference surface. This allows the planer to make the opposite face parallel, ensuring the board is properly dimensioned and flat.

What is the main difference between face jointing and edge jointing?

While the basic forces are similar, edge jointing requires extra force to keep the board flat against the fence. The fence, not the table, becomes the critical reference for the edge.

What techniques help joint a twisted board safely?

For a twisted board, balance the twist to avoid wasting material, stabilize it against the fence, keep the push stick and hands in a fixed position, and take a slightly deeper initial cut to establish a reference surface.

How does understanding wood properties like bow, crook, cup, and twist improve jointer use?

Knowing these wood deformations helps you position the board correctly, apply the right forces, and avoid instability during jointing. For example, placing the concave side down when jointing a bow increases stability and ensures a flat cut.

Why is proper pressure important for both results and safety when using a jointer?

Proper pressure ensures smooth, accurate cuts and prevents the board from distorting. Overly tight grip or excessive force can cause sudden release of energy if something goes wrong, increasing the risk of injury.