First, we need a dull chisel, like you can see above. That's me (Herrick Kimball) in the YouTube movie, My Whizbang Chisel Sharpening Jig, presenting a well-dulled, 1" wide, Stanley chisel. I purchased it for 75-cents at a yard sale.
By the way, all the pictures on this page are screen shots from the movie. If you like this idea, make sure you watch the movie. It's important.
The picture above shows how the chisel is clamped in the jig. With the assembly on a flat surface, the blade is touching down, while the front of the jig is raised up ever so slightly.
By the way, this jig is designed to grind a 25° bevel on the chisel, and it will also sharpen block plane blades.
In this next picture you can see the chisel being sharpened on an old belt sander, which is exactly what it is designed to do.
In the picture above, you can grasp the remarkably simple but amazingly effective concept of Whizbang chisel sharpening.
A sanding belt is cut to 1-1/2" wide and installed on the sander. I recommend a zirconia alumina sanding belt for this. Common aluminum oxide belts will also do the job, but they dull much more quickly than zirconia alumina.
The jig-with-chisel is held flat on the platen of the sander while the belt runs underneath. There are wood skis on the underside of the jig. So, the jig straddles the belt.
As noted in the picture, belt rotation and jig orientation is important. You want the belt running under the jig and into the chisel blade. This is safer than having the belt contact the point of the blade first. And speaking of safety...
Your belt sander is not going to explode when you grind a metal chisel blade. But those hot sparks may certainly find purchase on a bit of sawdust residue and smolder there before eventually flaming up. It's nothing to panic about. Just be aware of the possibility, and follow the common sense safety precautions on the label.
This next picture shows the desired result when grinding a chisel edge...
Once you have a wire edge all the way across the edge of the blade, it is time to stop grinding and move on to honing...
In the above picture I have replaced the zirconia alumina sanding belt with a worn out 180-grit aluminum oxide belt, and I am charging the belt with a bar of Veritas Green honing compound. The chisel remains as it was in the jig. Then hone the blade in the same manner that I ground the angle...
The blade is honed until the wire edge is gone, or mostly gone, as you can see in the picture above. The precise angle is perfectly retained.
Next, the blade is stropped...
I strop the blade on cardboard. Any clean, flat piece of cardboard that is in reach will work. Even the outside of a cardboard box.
Then, I test the blade for sharpness...
The best way I know to test the sharpness of a chisel blade is to hold it at an angle on the nail of my thumb, as you can see above. A sharp blade will "bite" ever so slightly into the nail surface and not slide off. A very sharp blade will hold its bite and not slide off the nail even at a very low angle.
You can achieve this kind of edge on a chisel in a couple of minutes, every single time. If the chisel is just a bit dull, and the edge is not damaged, you can renew it in a fast minute by simply honing and stropping.
A sharp chisel is a joy to use, and so is a sharp block plane...
Block plane blades up to 2-5/8" wide can be sharpened in the Whizbang jig just as easily as chisel blades.
Is This Jig
The Right Tool For You?
Well, it might not be. If you are a fine woodworker with expensive, high-quality bench chisels (like these from Lie-Nielsen) I do not recommend this sharpening method. Not at all.
However, if you work in the trades, and your chisels typically take a real beating, you are exactly the person who can benefit from this idea. The fact is, I developed this sharpening concept when I made my living as a carpenter and home remodeler. My chisels took a real beating. I needed a way to get a sharp working edge fast, right on the job site, without a lot of fuss and hassle. This jig, and the process I have just explained, will do that!
Now, having said that, I want to also make it clear that common, inexpensive chisels, like the 75-cent Stanley shown above, can be just as practical for most fine woodworking projects as a $55 Lie-Nielsen chisel.
Click Here for specifications, hardware parts kits, and already-made Whizbang chisel sharpening jigs.