One of the benefits of using plywood for any application comes from its dimensional stability; plywood doesn’t expand or contract with changes in humidity like solid wood does. This makes plywood an excellent choice for preparing drawers in many furniture types: cabinets, dressers, tables, etc. The dimensional stability of plywood means that the sides of the drawer won’t expand in humid weather; such expansion can cause the sides to bind in the top and bottom of the drawer opening. Using plywood for the bottom also minimize the movement from side to side, again preventing binding of the drawer along with its runners. Lastly, using plywood for drawer parts doesn’t require extra precautions during the preparation except when joining the sides to the front of the drawer using half-blind dovetails.
Drawers consist of five parts; a front, back, bottom and two sides. The front is normally composed of solid wood and reflects the overall style of the piece being built. The back, bottom and two sides are often composed of plywood and make ideal parts for a drawer. The back is cut to the size of the drawer opening minus the thickness of the bottom while the sides are cut to the depth of the drawer fitting and the height of the opening. The dimensions of the bottom reflect the manner in which it attaches to the sides and the back; if the bottom fits into a groove cut into the sides and the front, then the dimensions must account for this groove. If the sides, front and back surround the bottom, then the dimensions must account for the thickness of the front and back as well as the two sides— the thickness of the front piece is normally a little thicker than the rest of the drawer parts.
Attaching the drawer sides to the front and back pieces can be done in a number of ways. The simplest method to attach the sides to the back and front is using a simple butt joint. However, this simplicity comes with a cost; the joint is prone to separating and won’t stand up to heavy use. Another method to attach the front and back to the sides involves a rabbet joint. This joint involves cutting a rabbet in the sides of the front and back pieces (equal to the thickness of the side pieces) and inserting the sides into this rabbet. The benefits of this joint involve additional surface area for the glue and the ability to use mechanical fasteners to reinforce the bond between the side pieces and the front/back pieces. Driving a nail or small diameter dowel from the side pieces into the front/back pieces adds strength to the joint while remaining invisible on the exterior portion of the piece. Another common method, particularly useful if you have a table saw, is to cut a joint called a lock-rabbet joint. This joint attaches the front and back to the sides using a series of cuts that increase the glue area and add a measure of strength to the joint relative to a straight butt-joint or rabbeted joint. Cutting this joint is a little beyond the scope of this article and a good tutorial for cutting this joint has been published elsewhere.
The strongest way to attach drawer sides to the front and back to the sides relies on dovetail joints. Since showing endgrain is generally avoided whenever possible, drawer dovetails are usually half-blind dovetails. Unless your typical DIY’er is familiar with cutting half-blind dovetails by hand, the most effective way to cut them is using a dedicated dovetail machine and a router. However, using a router to cut tails out of plywood exposes one of the few weaknesses of plywood—blowout or tearout. Dovetail joints are a perfect match of pins and tails where the pins are cut in the front and back pieces while the tails are cut in the sides. Cutting the tails in the side pieces will occasionally result in the layers of plywood splintering as the router bit comes through on the backside. Since this backside represents the interior of the drawer, it won’t be seen when the drawer is closed, or is it visible on the outside of the drawer. However, it may cause problems on the inside of the drawer— splintered wood may damage drawer contents or give the person opening it a splinter. However, the easiest way to avoid this unpleasant occurrence is to cut the joint while using a very thin piece of backer-board—a sacrificial piece of thin wood behind the drawer side. The dimensional stability, ease of construction, reasonable cost and durability of plywood makes it an excellent choice for use in the fabrication of drawer parts.