Woodworking enthusiasts know the importance of strong and durable joints, and one of the most reliable joints in the craft is the mortise and tenon joint. To build furniture that will last, learning how to create square holes, or mortises, is essential. While most methods involve using a drill press, this article will guide you on how to achieve the same results using basic tools, particularly a round forstner drill bit.
To begin, imagine you want to connect two pieces of wood at a 90-degree angle. Start by using a pencil to mark the width of the connecting workpiece on the edge of the other piece. Since the tenon should not be the full width of the connecting board, mark the length of the mortise by coming in about half an inch from each side. The width of the mortise will be determined by the forstner bit used, so only one layout line is needed down the center.
To ensure accurate drilling, create a shallow groove over the center line using an awl. This groove will guide the tip of the forstner bit and keep the drilling on track. Align the forstner bit with the layout line, and make sure to mark the desired depth of the mortise on the shaft of the bit using a piece of tape. Hold the drill as straight as possible, and with a slow, controlled speed, start drilling. Stop drilling when the tape begins brushing the top of the workpiece.
When the two ends of the mortise are complete, you can remove the remaining waste in the center using overlapping holes. As long as the point of the bit finds a place in the wood, the guide rim doesn’t have to be fully engaged. With a sharp and high-quality forstner bit, it should bore straight downward even if it overlaps an existing hole. If the bit slips to the side halfway into the mortise, it can be cleaned up with a chisel.
Now that the majority of the waste has been removed, use a chisel to turn the row of circles into a single square. Take it slow and pare back the waste a little at a time, focusing on keeping the chisel straight up and down. To ensure straight lines, clamp a piece of wood with a square edge along the pencil line to support and guide the chisel. Note the hollow marks left by the edge of the forstner bit; once those are shaved away, the sides of the mortise should be relatively straight.
With the mortise created, you can now focus on fitting the tenon inside. It’s best to create the mortise first because it’s easier to make a tenon smaller to fit into a square hole than to make the hole bigger to fit around the tenon. If you need assistance with creating a tenon, additional resources can be found in the links below.
Mastering the mortise and tenon joint opens up a world of possibilities in woodworking. By following the steps outlined in this article, you can confidently create angled square holes in wood using a round forstner drill bit. Remember to choose high-quality tools for accurate results, and to take your time with each step to achieve the best outcome.
For more woodworking tips and tutorials, visit Stumpy Nubs’ YouTube channel.
Keywords: woodworking, square hole, mortise and tenon joint, forstner bit, drill press, basic tools, accurate drilling, chisel, waste removal, tenon fitting, wood joinery
