January 25, 2010
Easiest and Cheapest Methods of Fastening Two Pieces of Wood Together - Dowel Joints
Once you have learned how to drill truly vertical holes which are accurately centred (there are many jigs that take the skill clement out of this) you will find that a dowelled joint is an excellent multi¬purpose joint.
Whether the joint is through dowelled - made with the dowel holes drilled right through one component into the joining one, leaving the dowel ends exposed - or made with blind holes in the mating faces so that the dowels are hidden, certain basic rules are vital to success.
First, the mating faces must fit as closely together as possible. This is a matter of accurate marking, sawing and smoothing with a plane.
Second, the dowel holes must be ex¬actly aligned. In the case of a through dowel joint, this is no problem; the parts can be clamped and drilled as one. To help drill holes vertically you can use a try-square stood, blade up, on the work surface and used to 'sight' the drill. Or, better still, use a drill stand. Ensuring that the holes align in both components is a matter of marking centre lines accu¬rately with a gauge and remembering to mark which are the face sides and edges of the parts.
Third, only as much adhesive as is needed to bond the dowels in the holes and the faces to each other should be used. If the bottom of a dowel hole is filled with glue and the dowel is forced in, the effect is like a piston. The glue, under pressure, seeks to escape - in deli¬cate work this could split the wood. To avoid the piston effect, the dowels should be tapered to assist entry into the hole and grooved along their length to let surplus glue escape. The holes should be slightly countersunk in the mating faces.
Though you can buy a length of dowel-ling and cut your own, it is probably best to buy pre-cut dowels which are available in standard sizes from 6mm (diameter) by 25mm (length) to 10mm by 38mm, ready-grooved.
Dowels can be used to join framing battens or to join boards edge-to-edge, edge-to-face, or end-to-face. When using dowelled joints for framing, always use two or more dowels to ensure accurate alignment of the components and a rigid joint. You can substitute dowel joints for mortise-and-tenon joints. In carcase con¬struction, dowelled joints can substitute for dovetail joints though they are not as strong.
Wood is used a lot in homes, offices and hotels. You should know how to age wood. To make better shapes using wood, you must know how to saw wood with back saws.
