Eleven Grooved Box Step by Step – Part 8: Cutting the Box Open
Cutting the Box Open
View the original Woodwright’s Shop video here.
Getting the top edges flat and true is the next process. The glue up is never perfectly even. I use a number five plane for this as it has a bed long enough to use the opposite side of the box as a reference surface. I set the plane on the box at about a 45 degree angle and start the blade exactly in line and over one of the miter joints. The direction to move is determined by the grain of the side pieces. Then push the plane down the side and when the blade nears the next corner, slowly rotate 90 degrees and continue down the next side. Continue this rotary sequence until a shaving is coming off evenly from all four sides.
level the bottom surface as well.
Set a marking gauge to a distance from the top edge to just above the center of the (now hidden) lip groove. Mark the box carefully and heavily on all four sides.
I have a nice old dovetail saw for cutting the box open. Dovetail saws are rip filed and make a very thin kerf, but any rip filed fine toothed saw would do. Begin at the corners, cutting in at a shallow angle, gradually working back along the line. Rotate the box and start the next corner. Remember the saw is guided by the kerf itself so you have to watch both sides the saw is working. Work carefully and watch the line.
Once you get two or more sides cut completly through, the vise wants to pinch the saw blade. Insert a steel ruler in the cut side kerf to minimize that problem.
Continue rotating the box, sawing a bit and rotating again until all four sides are separated. It’s always a good feeling to see the inside for the first time (unless you find a lot of glue squeeze out to clean up).
Use the circular planing technique as described above to level both freshly sawn surfaces. Remove all saw marks with the plane.
I do a final flattening of both sawn surfaces using a sheet of sandpaper on the (flat) table saw top. First 150 grit then 280.
Hold the box top and bottom together to check how good you have trued them up. Can you see the cut line? It doesn’t have to be absolutely perfect as later we will ease both edges slightly with a block plane which will cover up small gaps.