Popular Mechanics (South Africa)
DOVETAIL ANGLES
Some say hardwoods require a steeper angle compared to softwoods. Dovetail angles are usually quoted in ratios, for example 1:5, 1:6, 1:7, and 1:8. This is a remnant from times gone by. It means that if you draw a 90° angle and one line of the angle is five inches long and the other is one inch long, a line (hypotenuse) drawn between the ends of the two initial lines will give you the slope angle required for your dovetails – in this case, 1:5. (Refer to the dovetail ratios and angles drawing, below.) The angle you choose is entirely up to you. We opted for a 1:8 ratio for our joints.
STEP 1:
Four-square your two pieces of wood for the joint. Make sure they are exactly the same width and thickness as each other. For this practice joint, the boards should be 150 mm to 250 mm long, 140 mm wide and 12 mm thick.
STEP 2:
Begin by marking out the orientation of the pin and tail boards – inside and outside faces, top and bottom, front and back. Remember that in cabinetry, the tail boards always make up the sides of drawers and carcasses, and the pin boards are usually the fronts and rears of drawers and tops and bottoms of carcasses due to the mechanical ‘locking’ action of the joint.
STEP 3:
Apply blue painters tape to the boards as per the images. An eternal argument exists among woodworkers as to which part of the joint to cut first. We always use the ‘tails first’ approach – our students find it easier, and by doing so you can lay out and cut multiple tail boards simultaneously when clamped together, for example when matching drawer sides.
Once you’ve established the orientation of the boards and marked them clearly, scribe the joint baselines on both boards using the marking gauge set to the exact thickness of the board. Scribe the tail board on both edges as well. There’s no need to scribe the edges of the pin boards. Setting the gauge to the board’s exact thickness means there are no proud pins that will interfere when you glue and clamp the joint.