Grinding Bevels
Different woodworkers and further to that, different cultures, prepare their edge tools in a multitude of ways. For my most common edge tools, the chisel and the plane, I grind a bevel and hone a secondary bevel with my India stone finishing with an Autosol infused piece of wood, refreshed as required. I recently made a change based on observations I’d seen on some old tools. This comes with a note of caution, just because I’ve done this doesn’t mean you should!
What I noticed was that many old chisels and plane irons had long grind bevels, see above! 20 degrees and less. Many of you would know that the default angle to grind a chisel or plane iron is 25 degrees. The potential I saw in the shallower bevel was that I could hone the edge for longer with less frequent trips to the grinder. I’m pleased with the results.
I also made another change. My normal way of grinding a tool at work has been a Tormek grinder. This is for various reasons, but the main two to control sparks for insurance purposes and how easy it is for anyone to use. But at home I decided on a different approach. I simply used used a cheap 6” high speed bench grinder from the supermarket with it’s standard grey wheels and just went free hand.
The jack plane iron shown above is the result of that effort. There is much said about the risk of overheating and caution is important. However by letting the wheel do the work rather than quite literally pressing the matter it was no problem at all. The iron was warm but never got to the point of needing a quench in water, although it is wise to have some water to hand. Is this approach right for everybody? Absolutely not! You need to be in complete control of how you work for your safety and confidence. If grinding an edge using a honing guide and sandpaper works for you and you feed comfortable, stick with it. If you have a water bath system like the Tormek, stick with it if you’re happy. I’m just very pleased how simple this can all be and most importantly affordable.
It should be noted that not all chisel and plane irons are well suited to this approach. Certainly Japanese tools should be prepared with one bevel. I can’t comment further as I don’t have the experience using them, suffice to say my approach is not universal. Nor do I use this method on narrow irons such as a plough plane or narrow chisels. Sometimes honing the whole bevel can be faster!
The reason for sharing the image of my plane iron with you is that it’s not a “perfect” grind but it works! New tools are made to such high standards and come with a clinical level of perfection. This old plane iron is forgiving, it already looks as if it has lead a life. The narrow strip on the very tip is honed, nothing more. Happy grinding…