Building a four-sided box is great practice for learning to build frames, cabinets, and shelving. Learning to make lap joints is helpful for a lot of projects, especially ones that you want to use hand tools for.
You will need to start with four small boards, cutting the lengthwise boards exactly the same length and the end boards the exact same length. Of course, you can make all four boards exactly the same for a square, as opposed to a rectangular, box.
When all four boards are cut, you will need to measure the width of each board and mark the center with a ruler and pencil. Square up the flat board on a level table, press the ruler end into the table, and use the straight edge to mark the short line from front to back of each board on both ends.
Cabinet makers make marks for orientation. This is really helpful when assembling something that needs to be perfectly square. You don’t want to accidentally cut a joint in the wrong side and have to start over. With your same-length boards laying flat on the table, side by side, close them together like a book. Draw a triangle that is half on one board and half on the other. Do the same for the other two pieces. When you set up your boards in the way that you want them orientated for your completed project, you can see that the triangles are aligned and all pointing the same direction.
From the center mark that you made on the end of each board, mark the sections to cut away for lap joints, alternating top and bottom waste areas for each joint so that the top of one end matches the bottom of the opposite end of the joining board. Use a mortising gauge to mark an exact depth and color in the waste area so that you don’t get confused.
Cut away waste area with a backsaw, which is a handsaw with spine down one side to hold the blade steady. Backsaws can cut on the pull or push. One that cuts on the pull is easier to control.
Cut center cut down to mortising gauge line. Build a “hard shoulder”. Use sharp chisel to make a scribe line. Hammer chisel gently into lines to start the hard shoulder. Notch out the waste area until it is easily removed. Square off by shaving off excess with your chisel. Frequently check to make sure that everything is squaring up and fitting together nicely.
Dry-join pieces together with clamps and no glue to make sure that all joints meet up perfectly. Check to make sure that everything is also square. Measure from corner to corner in each direction to make sure that both measurements are the same.
Apply wood glue with a small brush to both sides of all joining surfaces. Place pieces back into clamps. Ignore squeeze-out glue for now. Let it sit for 30 minutes. Glue will be slightly gelled, so you can use a small chisel to scrape away excess without smearing the glue. Let glue dry and set for two more hours.
Use a small hand plane to smooth out any high areas around the outside of your box. Sand with a fine-grit sandpaper to finish.
About the Author: Dave Murphy is the founder and president of Good Wood, Inc., which makes a high quality wood dowel and the best hardwood dowel on the market. They also create wooden balls, wood knobs, wooden toy parts, custom wood parts, and more. They offer safe wood finishing, wood turning and can import from off-shore when necessary. Visit http://www.goodwoodinc.com for all of your wood product needs.