How can I bore with a holesaw without burning the wood? I don’t have any drill bits large enough to use in place of the holesaw.

Advertisement
101948543.jpg
Drill relief holes so they intersect the holesaw cut, but donu2019t go beyond. Debris from the holesaw will slip out these relief holes.

Q:

How can I bore with a holesaw without burning the wood? I don't have any drill bits large enough to use in place of the holesaw.
—Steve Fuller, Ellsworth, Maine

A:

It's an inherent problem with holesaws, Steve. With no built-in way to eject debris from the cut, the saw continuously builds up friction as it spins, resulting in burns.

101948544.jpg
With the drill press running, spray the lubricant onto the holesaw's outer and inner walls and teeth. Leave it running until dry.
101948545.jpg
In maple, we made the hole on the right using a new holesaw. The unburned hole (left) was made using relief holes and dry lubricant.

To combat this, first make a 116 "-deep cut with your holesaw, then stop. Use a Forstner bit or brad-point bit to drill a pair of relief holes just inside the rim cut. Now, spray your holesaw with a quick-drying lubricant, such as Bostik DriCote. Resume cutting the hole with the holesaw, periodically recoating it when it shows signs of heating up. If you want to keep the inside portion of the hole—making toy wheels, for example—simply drill the relief holes to the outside of the circle.