Sharpening: Regrinding a Bevel
by Patrick Harper - Blood, Sweat, and Sawdust
Keeping your tools sharp is paramount to enjoying the time you spend in your shop working wood. This is even more important to those of us who have limited time to spend in the shop. If you’re like me, you enjoy building furniture more than you enjoy sharpening your tools. The best way to minimize the time you spend maintaining your tools is to have a solid game plan and become as efficient as possible. The only way I know to accomplish this is through practice.
For me, the first step in the process is determining whether a tool needs to have its primary bevel reground, and that is the topic that I want to explore today. Whether from edge damage or a secondary bevel that’s grown too large, you’ll eventually want to regrind your bevels. I find that the quickest way to do this is with a hollow grind using a benchl grinder. Below I will describe the process that I use on my 8″ low speed grinder.
Here, I have determined that the edge of this chisel is damaged and no longer square. I start by using a square and a sharpie to mark a reference line just shy of the damaged area.
Next, I position my tool rest roughly perpendicular to the wheel and grind to my line. This will leave a flat spot that is square to the sides of the blade. Use a steady side to side motion until you reach your line.
Once I have a square edge, I reposition the tool rest to the desired bevel angle and carefully grind until the flat area is almost gone. For general work, I prefer a 25 degree primary bevel. Keeping a small portion of the flat area makes it easier to avoid overheating which can remove the temper from the blade. However, you don’t want to leave too much, or honing might become a chore. If I were simply regrinding a dull edge, I would keep a sliver of the secondary bevel, as this also reduces the amount of time spent honing the edge.
Here are some key points to remember:
Always keep the tool square to the wheel unless creating a cambered blade is the desired result.
Apply consistent pressure to the tool when moving across the wheel.
Move your tool across the wheel at a steady speed.
Always dress your wheel before grinding. I find that rounding the corners of the wheel slightly help with transitioning the blade across the wheel.
You’ll know you’re on the right track when you can consistently produce a new bevel that consists of a single facet across the entire face of the blade. My next post will detail the honing process.