When using dowels for joinery, it’s important to make sure that any dowel holes you drill are perpendicular (at 90 degrees) to the wood.
If your holes are not perpendicular, your joint will not connect properly and there may be gaps. This can be a big problem in furniture making as it can cause other parts not to fit correctly.
Drilling freehand should be avoided. To guarantee perpendicular drill holes, a drill press or dowelling jig should be used.
Using a drill press
A drill press is a tool with a motorised, vertical drill bit.
A side mounted handle enables the user to raise and lower the bit.
The tool itself has a drilling surface on which you can rest the piece of wood that you are drilling. The drill bit is perpendicular to this table.
The drill bit cannot move from side to side in a drill press. If the piece of wood you are working on is kept flat on the table, it is not possible to drill anything other than a perpendicular hole!
Using a dowelling jig
Dowelling jigs have metal tubes called ‘drill bushes’ that guide the bit of a hand drill or power drill to make sure it stays perpendicular to the wood.