What are the Parts of a Finger Joint in Wood?
A finger joint, also known as a comb joint, is a strong woodworking joint formed by interlocking "fingers" or "teeth" cut into two pieces of wood. These meshing pieces create a strong bond, often enhanced with adhesive.
- Fingers (or Teeth): These are the interlocking wedges or projections cut into the ends of the two pieces of wood. They are the crucial element creating the interlocking strength of the joint. The design and number of fingers influence the joint's strength and aesthetic appeal.
- Notches (or Grooves): These are the complementary recesses cut into the mating piece of wood, precisely matching the fingers to create the interlock. Accurate cutting of the notches is essential for a secure and strong join.
- Structural Adhesive (Optional but Recommended): While the interlocking fingers provide significant strength, using a structural adhesive further enhances the joint's durability and prevents gaps or weaknesses. The adhesive fills the minute spaces between the fingers and notches, providing a superior bond.
Types and Considerations:
The design of the fingers (e.g., straight, angled, varying widths) can influence the joint's strength, appearance, and the type of equipment needed to create it. Many machines exist specifically for cutting finger joints efficiently and accurately, offering various patterns and finger configurations. The selection of the type of finger joint depends on the application and the desired strength.
Many sources highlight that a well-executed finger joint is stronger than the wood itself due to the large surface area of the interlock and the added support of adhesive. This makes it suitable for applications requiring high strength and stability, even in end grain, where wood is naturally weaker.