How to Grind & Sharpen a Router Plane Blade
Grinding and honing a router plane blade can be a challenge. It’s a freehand operation as there’s really no way to jig up the blade for honing.
A hollow grind is a huge aid in freehand honing. Whenever I’m honing a blade freehand, I always grind a hollow bevel. However, grinding a hollow bevel on a router plane blade using a typical bench grinder isn’t possible. The “L” shape of the blade prevents the bevel from contacting the wheel at the proper angle.
Derek Cohen of inthewoodshop.com came up with a solution to this problem. His method for grinding a router plane blade utilizes a sanding drum in the drill press and a simple wooden cradle to hold the blade in the proper orientation. I discovered Derek’s method some time ago and thought it was brilliant, so I decided to demonstrate it in the video below.
Tag:Sharpening
2 Comments
A sharp edge is an intersection of TWO planes. We assume that the bevel gets sharpened and the other edge just needs to be flat. Why not “switch”? Keep the bevel ” flat” and focus on the flat to produce the sharp edge? I’ve been doing that for years and don’t notice any decrease in the thickness.
You can. I know some people who do that and it works fine. It’s just a larger area to maintain. By hollow grinding the bevel, touchup honing is much faster for me, because I only have to focus on the small bevel at the tip of the hollow grind. I am able to raise a burr much faster and easier by stoning the hollow ground bevel vs stoning the flat bottom. I also feel like I get a sharper edge this way too, but that’s really subjective and might just be me justifying my method to myself 🙂 .
The only risk I see to what you are suggesting is becoming impatient when trying to raise a burr on the flat side and unintentionally dubbing or putting a bevel on the bottom of the blade. If this dubbing or bevel gets steep enough, it will reduce the clearance angle under the blade enough that the plane will not cut no matter how sharp the edge is because the bottom bevel will rub. As long as the bottom of the blade is kept flat and no secondary bevel is created on the bottom of the blade, then what you’re doing works fine.