A Forstner is a beneficial tool for drilling; however, they tend to lose their drilling power. Once dull, the bits won’t cut clean holes like they used to; it becomes impossible to drill holes even in softwoods. Worst of all, blunt drills can be quite dangerous to use and require a lot of energy to work with.
Instead of buying a new Forstner, you can use some simple techniques to restore the cutting power of your tool. I advise you to sharpen your tool frequently to avoid the work for a completely dull Forstner.
How to Sharpen Drill Bits
The process of sharpening a drill bit may be dangerous. I suggest you wear safety glasses to shield your eyes from flying metal pieces. This is a tricky but straightforward process and can be done by yourself; you just have to be very careful.
There are three main ways to sharpen a bit; using a file, a Dremel, or by hand with a bench grinder. All these procedures will produce excellent results. All you have to do is follow simple rules not to mess up your drill bits even further.
Always sharpen the bit’s size and not its circumference, as this will tamper with the size of the bit. Furthermore, make sure the drilling bits are symmetrical to avoid non-straight holes in your next project.
Learning how to sharpen a Forstner bit by yourself will save you lots of money for replacing them. To begin, follow the simple procedures below.
Sharpen Drill Bits with A Dremel
A Dremel is an essential tool for a handyman; it can be used for drilling as well as for sharpening drilling bits. There are many types of Dremel, but I recommend ½ inches as it’s faster compared to the others. Before you start, make sure you put on safety glasses, hearing protection and position yourself correctly.
Clamp down your bit tightly to a bench vise to ensure that it stays intact while you are grinding it. Then scrape away any debris from the edges of your drill using a Dremel. Next, grind the drill bit edge continuously until it has a smooth cutting point. Next, do the same for the other side of your drill bit.
Test it to see if it is ready by drilling into a testing log to see if you smooth cutting. If there is any difficulty, repeat the procedure until your drill bits are sharp.
Sharpen Drill Bits with A File
The first step is to wipe away any particles, grime, or dust from the drill using a clean piece of cloth. If the dirt is stubborn, you can use a damp cloth. Next, you can hold the Forstner drill down firmly using your hand.
However, I suggest using a clamp instead to avoid bruising your hand due to friction while filing. This way is more accessible, and you won’t use much energy anyway.
Place the file on one of the blades at an angle of 60 degrees and run it down the edge of the drill 6 to 8 times. Repeat this procedure to the other side of the bit. Draw the file once up and across the underside areas to file off any metal burrs.
I prefer to use machine oil to apply to the drill bit after filling, but you can also water for a final touch-up.
Sharpen Drill Bit by Hand
Hold the cutting face of the bit to a parallel position with the grinding wheel. Bring the bit into contact with the wheel carefully. Use your dominant hand to hold the bit firmly while using your other hand to support the side of the bit.
Lower the bit slowly to the grinder and touch the tip of the bit lightly to the belt. Make sure to hold the bit in a straight position without rotating it as it touches the grinder. This process usually produces a lot of heat; I suggest you have cold water in place for cooling the bit. Dip the bit in water whenever it gets hot.
When you are done sharpening the cutting edge, spin the bit to work on the other side. Make an effort to maintain the same level of sharpness on either side. This process is continued until all the edges are sharpened.