A plate joiner is a woodworking tool that is used to cut a narrow slot in a piece of wood. A wooden biscuit, a small piece of compressed wood that is usually oval shaped, is glued into this slot so that half of the biscuit is sticking out. This half of the biscuit is then glued into a slot in a second piece of wood, creating a firm joint between the two. Plate joinery is often referred to as biscuit joinery because of the small, wooden biscuits that are the backbone of the joining method.
The most popular biscuit sizes are #0 biscuits that measure 5/8 inch (1.58 cm) wide by 1 3/4 inches (4.44 cm) long, #10 biscuits that measure 3/4 inch (1.9 cm) wide by 2 1/8 inches (5.39 cm) long, and #20 biscuits that measure 1 inch (2.54 cm) wide by 2 3/8 inches (6.03 cm) long. The plate joiner blade is 4 inches (10.16 cm) in diameter and the biscuits sizes are determined by varying arc sizes of the blade. One plate joiner can cut slots to accommodate any biscuit size.
Plate joinery began in Europe in 1955. Invented by a Swiss cabinetmaker and engineer Herman Steiner, the original plate joiner was developed mostly by accident as a way to join chip board quickly and easily. He founded the Lamello Corporation and began marketing the first plate joiners in Europe. Marketing eventually included the United States and Canada, but the tool and method did not catch on very quickly. Over time, American woodworkers saw the beauty of such a simple joining method.
When plate joiners became popular in the United States and Canada, American tool manufacturers decided to get in on the game and developed less expensive models of their own. The design of the tool is quite simple. Most tool manufacturers already produced a 4 inch (10.16 cm) grinder and simply modified the design by adding an adjustable plunge-cutting fence that is able to grip the stock while it is being cut to reduce slipping and miscuts. The blade used is a small carbide-tipped saw blade that is modified to fit the grinder mandrel.
Dust and debris collection is accomplished via a dust bag that is attached to a discharge hole on the tool. Tool manufacturers added a small modification to the plunge fence to make dust collection more convenient for the user. When cutting softer woods like pine, the dust collection port can become clogged and should be cleared before continuing work with the plate joiner. The collection bag should be emptied after each use to keep it clean and clear.
There are many quality adhesives on the market that are used regularly by woodworkers. Everyday wood glue is an effective option when using a plate joiner. Polyurethane glue foams up with the application of a small amount of moisture; the foam works its way into the nooks and crannies inherent in a biscuit joint. Both glue types create a strong bond that, with the help of the biscuit, will last for a long time.
