Finger joints, also known as box joints, are a popular woodworking technique for creating strong, interlocking corners in boxes, drawers, and other woodworking projects. In this article, we’ll cover how to make finger joints using a table saw.
Materials and Tools
Here’s what you’ll need to make finger joints with a table saw:
- Table saw
- Dado blade set (stacked or wobble dado blade)
- Miter gauge
- Finger joint jig
- Wood pieces (workpieces)
- Pencil
- Tape measure
- Clamp
- Sandpaper
- Wood glue
Step 1: Set Up the Dado Blade
- Unplug the table saw for safety.
- Install the dado blade set onto the arbor of the table saw according to the manufacturer’s instructions. Ensure that the dado blade set is wide enough to cut the desired finger width.
Step 2: Create the Finger Joint Jig
- Attach a sacrificial fence to your miter gauge. The fence should be longer than your workpiece.
- Cut a dado slot in the sacrificial fence by running it through the table saw with the dado blade installed. The slot will serve as a guide for the jig.
- Attach a spacer to the sacrificial fence. The spacer should be the same width as the desired finger width.
- Secure a stop block to the sacrificial fence on the opposite side of the spacer.
Step 3: Prepare Your Workpieces
- Measure and mark the desired finger joint length on each workpiece.
- Ensure that the workpieces are square and have smooth, straight edges.
Step 4: Cut the Finger Joints
- Set the blade height to match the thickness of your workpieces.
- Place the first workpiece against the spacer and sacrificial fence on the miter gauge.
- Turn on the table saw and carefully guide the workpiece through the dado blade to make the first cut.
- Remove the workpiece from the blade and place the cut notch onto the spacer.
- Continue making cuts by aligning the previous cut with the spacer, ensuring that the workpiece is firmly against the sacrificial fence and stop block.
- Repeat the process for the other workpiece, starting with a cut aligned with the edge of the workpiece.
Step 5: Test Fit and Clean Up
- Test fit the finger joints to ensure a snug fit. If the joints are too tight, sand them lightly. If they’re too loose, consider adjusting your jig or dado blade set and re-cutting the joints.
- Apply wood glue to the joints and assemble the workpieces, clamping them together until the glue is dry.
Step 6: Sand and Finish
- Once the glue is dry, remove the clamps and sand the finger joints smooth.
- Apply your desired finish to the completed project.
By following these steps, you’ll be able to create strong, attractive finger joints using a table saw. Practice and experimentation will help you perfect this technique and enhance your woodworking projects.
| Step | Description |
|---|---|
| 1. Set up the table saw | Install a dado blade, miter gauge, and finger joint jig |
| 2. Wood selection and preparation | Choose straight, flat, defect-free wood, and let it acclimate |
| 3. Measure and mark | Determine the finger width and mark the locations |
| 4. Set up the jig | Adjust the finger joint jig to the desired width and position |
| 5. Cut the first set of fingers | Make the first set of cuts on one end of each workpiece |
| 6. Cut the second set of fingers | Make the second set of cuts on the opposite end of each workpiece |
| 7. Test fit | Test-fit the joints and make adjustments if needed |
| 8. Sand and finish the joints | Sand the fingers and apply the desired finish |
| 9. Assemble the joint | Apply glue to the joint surfaces and clamp the pieces together until dry |
Additional Tips
- Make sure to use a sharp dado blade set for clean and accurate cuts.
- When cutting multiple finger joints, consider using a stop block and spacer system to ensure consistent finger spacing.
- Practice cutting finger joints on scrap wood before working on your actual project to refine your technique and make any necessary adjustments to your jig or dado blade set.
Safety Precautions
- Always wear safety glasses, hearing protection, and a dust mask when operating a table saw.
- Use push sticks or push blocks to guide the workpiece through the cut, keeping your fingers away from the blade.
- Ensure that the table saw is properly maintained and that all safety features, such as the blade guard and riving knife, are in place and functioning correctly.
- Work at a comfortable and controlled pace to minimize the risk of accidents.
Wood Selection and Preparation
- Choose wood that is straight, flat, and free of knots or other defects to ensure the best results.
- Make sure your wood is acclimated to your workspace’s humidity and temperature to minimize wood movement, which could affect the fit of the finger joints.
- Ensure the wood is cut to the desired length and width and has square edges before starting the finger joint process.
Finishing and Assembling the Joint
- Sand the individual fingers of the joint lightly to remove any rough edges or saw marks.
- Apply wood glue to the mating surfaces of the finger joints and assemble the joint, ensuring proper alignment of the fingers.
- Use clamps to hold the joint together while the glue dries, making sure to apply even pressure across the joint to avoid misalignment.
- Once the glue has dried, remove the clamps and sand the joint as needed to achieve a smooth, flush appearance.
