How to Make a Miter Joint on Plywood

A miter joint is used for joining two edges to form a corner. The edges of the two pieces to be joined through a miter joint have to be cut at 45-degree angles and then joined together to make a right angle.

A miter joint is generally used for constructing boxes where the sides of the box have to be joined together to form corners while hiding the edges. A miter is usually not that strong a joint for woodworking. However, there are ways through which a miter joint can be strengthened.

Why Use Miter Joints?

Plywood edges are very disconcerting and do not look attractive as they show the plies that have been joined to make the plywood. Thus, it is best to cover any exposed plywood edge, such as the case in a beaded plywood ceiling at the juncture of the ceiling and the wall. This is where a miter joint on plywood can come in handy.

Although it might have to be reinforced somehow, the miter joint can help hide the edge of the plywood and only give the observer a chance to view the veneer instead of the plywood plies. Usually, crown molding is used for this purpose, but it also requires a miter cut.

Miter Cuts on Plywood

Before understanding how a miter joint can be made on plywood, we must first learn how to make a miter cut. Making a miter cut is not a difficult thing if you have the right equipment available to you. For instance, a miter saw set at a 45-degree angle is the best means for making an accurate miter cut. However, if you do not have a miter saw, you must use a table or a very accurate track saw to make the miter cut. Be careful when making the miter cut, as it will make the edges fragile.

Making a Miter Joint on Plywood

Having made the miter cut on both the edges of the plywood that you are trying to join together to form a miter joint, it is time to join the two edges together using an adhesive. However, the joint will not hold only because of the glue, as the joint would be very weak. To strengthen the miter joint on plywood, experts recommend using a square block of wood to support the joint. However, such a supporting wood block can only be used to make boxes with a hidden interior. In the case of a miter joint being placed on a ceiling and wall juncture, there is a need for a spline to be made in the miter cut or to make a compound miter cut to strengthen and hold the joint.