Although not an exhaustive list of joints, you will find that the vast majority of wooden boxes employ one of these types to secure their corners.
A hallmark of craftsmanship and strength, the dovetail joint can be cut by hand, machine or a combination of both. There are a number of different types of dovetail corner joints, but the most common are through and half-blind.
This simple, yet strong, joint can be created so the dowels are hidden or exposed. A basic butt joint can be strengthened with hidden fluted dowels, or a rabbet butt joint can be cut first, dowel holes can be drilled and contrasting solid dowels can be inserted and cut flush.
Generally machine-cut, box joints are very strong due to the large amount of glue surface. They are also very strong visually and, if used tastefully, can accentuate a project.
Great for joints that don’t require a lot of strength, mitres are easy to cut and can be assembled with masking tape. A basic mitre joint is a very simple looking, uncluttered joint.
A spline adds a lot of strength to this otherwise very simple looking joint. A groove should be cut as close to the inside of the joint as possible, so the ends of the spline don’t weaken the outer edge of the joint. If the joint is of solid wood, and is at all wide, the grain direction of the spline should be taken into account. Run its grain in the same direction as the box sides.
Once a basic mitre joint has been machined and assembled, you can add straight or dovetail shaped keys into its edge. Everything from a table saw to a router to a handsaw can create the recesses in which the keys can be glued. If the keys are made of contrasting material, the look can be quite powerful.
With the mitre joint assembled, use a handsaw to cut thin kerfs into the outer surface of the corners. You have lots of flexibility on what the joint will look like, as stopping at different depths, cutting at angles and using many different contrasting woods is an option. Once the kerfs are cut, glue and insert strips of veneer. Be sure to test the veneers you want to use with the saw you’re using to cut the kerfs, as they must match up closely for a tight, strong joint.
This reasonably strong, and very simple, joint is usually made on a table saw. A groove, no bigger than one third the depth and width of the thickness of the thinnest piece, is cut across one side, and a mating tenon is machined on the end of the other workpiece by cutting a dado at its end.
A vertical leg can have a groove cut into it, then cross-rails can be fit to that groove. A panel can be cut for between the rails and legs, similar to a frame and panel door. This leaves a very formal look.
Many boxes are cut from a single, thick piece of wood, and therefore don’t need special consideration given to their corners. Bandsaw boxes fall into this category, but there are other ways of creating a similar type of box; hollowing the cavity with drill bits and/or hand tools and using a scroll-saw are two examples of similar styles of boxes. Turned boxes also fit into this category.
Rob is a studio furniture maker and the editor at Canadian Woodworking & Home Improvement. Instagram at @RobBrownTeaches
Share your thoughts in the comments section of this article.
Hi Denis,
Why don’t you send me a few photos of the piece? Both detailed and overall photos will help me have a hood look at the construction. Heating it may help; impossible to tell without knowing what glue was used. My email address is at the bottom of the article.
Rob, was looking at your article about box joints for a clue how to open a themometer box from a wall mounter barometer. The box has a glass front set in a groove. I cannot see any brads or pins holding the ends but need to open the box to resecure and clean the thermometer. Would warming the piece soften any glue? The corners are perfectly mitered with no visible fastenings. Any advice?