Edge joints are an easy way to make strong, quiet joints. Learning the basic joints will give you a strong background on which to build further knowledge.Edge Joining For Panels and Table Tops Edge joining is the process of bringing two or more boards together edge-to-edge, and is done in order to create a wider board. The first thing to consider when planning to edge join two non-book-matched boards together is how the boards look next to each other. This is a two stage process. First, look at the boards in their rough sawn state before milling them. Look at the rough sawn boards to see potential matches of grain pattern. Use chalk to mark the significant patterns in the boards, such as cathedrals and knots. Do the grain patterns of the boards have anything interesting I want to showcase? What direction does the grain run? How do the cathedrals (arched shape of the grain line) run in the boards?
The three cornerstones of edge joints, commonly referred to as "butt joints" are the Edge-To-Edge, Edge-To-Face, and Face-To-Face.Each of these joints are formed by when each piece of wood is machined straight and square before being fixed to its mate.
Many woodworkers find it difficult to believe, however the simple glued edge joint is remarkably strong. Having a good clean and flat edge mating with another similar flat edge produces a joint that is just as strong as the surrounding wood. The use of joining devices such as splines, biscuits, dowels or keys can actually weaken some joints especially when the material of the device is weaker than the wood to which it is attached.
The joints used to connect the vertical components of cases, cabinets and furniture require strength and often a measure of ease of assembly. The mating edges are long grain to long grain and are therefore present the strongest joints. And since the grain of the mated surfaces run parallel to one another, there is no worry regarding cross grain joint instability.
These joints are the simplest of all edge joints. Their primary purpose is to produce wood stock that is thicker than can be economically purchased by gluing together two or more flat boards. The key to successful face-to-face joints is to have the surfaces flat and clean.
Edge miter joints offer the ability to completely hide the end grain of the joined pieces, providing a smooth, clean surface to view. The largest problem with miter joints is that they are very difficult to assemble. There are, however, some variations that offer some assistance in assembly.
A rabbet is formed by removing a section of wood from the edge of a board. When you place another board into this recessed section, a rabbet joint is formed. This joint is produced when only one of the pieces has a rabbet. Traditionally, rabbet is placed on the back side of the face that is the most visible. This produces a joint that has a clean and undisturbed face, and the small amount of edge grain is only visible from the lesser-viewed side.
A router can greatly speed up the process of preparing edges for joining, however much effort can also be wasted unnecessarily. As has been stated, a simple glued joint is very strong, and is sufficient in most situations. Where a router excels, though, is for creating interlocking joints which also increase the wood surface to be glued.