Bevel Angle
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Man, I’m going to need a lot of sandpaper…
I recently grew frustrated enough with the performance of some of my planes (scudding on hardwoods) that I purchased one of those neat protractors that has the bar on it (useful in accurately measuring bevel angles) and measured my tools. Sure enough, over the last couple of years it seems I have worked several of my bevels up around 40 degrees which is just too steep for a clean shaving cut. In the world of Facebook forums, many/most members seem to scoff at the idea of hand-sharpening as being lazy and swear by using honing guides. While I indeed have one, I also find it to be cumbersome to use on chisels (and frankly, nearly useless on chisels narrower than 3/4″. Also, I frankly enjoy hand sharpening, even if it carries the risk of being “less consistent” than a honing guide which will “guarantee consistent performance”… In any event, after finding out how off the bevels were on my plane irons (no doubt a result of me gradually steepening the sharpening angle over time in an attempt to ensure I was sharpening the edge), I took it upon myself to regrind them. Needless to say, the performance improvement has been eye-opening.
Next up, regrind my chisels to the proper angles (25 for the main bevel, 30 for the microbevel and then create the macro-camber via the hand-sharpening process). Yes, I am using my honing guide for the initial re-grind (to ensure squareness and accuracy of the initial grind). But I still enjoy hand-sharpening and plan to continue doing it once the initial re-grinds are done. I’ll just have to be more mindful in the future of how easy it is to screw up the angle over time and how that affects the performance of the cutting edge.
So, with that said, are there any particularly useful methods of re-grinding narrow chisels to a square/25 degree bevel since my honing guide will not clamp an object that narrow?
Pics: The 1″ chisel was freshly reground and sharpened. The 3/4” has not been reground and the overly-steep bevel/camber is easy to see by comparison.
I like to hollow grind my chisels and plane irons. My grinder is set to deliver a 25 degree bevel. I also like to freehand hone on diamond stones. The hollow grind allows me to register the iron on the stone. I hone a micro bevel by just lifting the iron up a bit.
The first Stanley #5 I ever bought had obviously been used a lot. It had a beat up old iron but of very high quality steel and it was heavily cambered. The primary bevel was way less than 25 degrees and a little bit of honing had been done on the back of the iron as well, making it sort of similar to a knife. That setup would plane soft woods like pine as if they were butter. I’ve tried to copy that whenever I’m working in softer Woods.
I can put a 1/4″ chisel in my cheap-o Eclipse guide.
In your routine sharpening, it helps to forget about the edge when you begin. Get a feeling for that 25-degree angle (or something less than 30), and just grind the heel on your coarsest stone. Every sharpening is an investment in keeping that heel down. I start at that low angle and watch the heavy scratch pattern approach the shiny tip. When it’s just there, or just before, I move to the next stone. I now adjust my stroke so that my fine and superfine end up working at the angle I actually want for the task. I guess I’m making a double convex, but I don’t think of it that way.
You take relatively few passes at the edge on the finer stones to get sharp. This distributes the work over time so that you never have to spend a huge amount of time going from 40 to 25.
You don’t need to make it as complicated as I made it sound. Just work the heel on the coarse stone. That’s the coarse stone’s purpose, in my opinion.
I too prefer to hand-sharpen my chisels. To help maintain the correct sharpening angle I stand a 30 degree triangle of wood next to my sharpening stones which I use as reference for holding the blade at the right angle at the start of and during sharpening.
I also found narrow chisels difficult to keep square to the stone. I found it helpful to attach a 3 or 4 inch thin strip of wood at 90 degrees across the back of the blade (held on with a small criss-crossed elastic band), which emphasises visually if I’m presenting the blade out of square to the stone.
Might sound a bit cranky but it works for me!
I also sharpen freehand and use a 30 degree wedge to keep track of what I’m doing from time to time. It has really been helpful and adds basically zero extra time to the process.
Actually I need to make a 25 degree wedge just to check myself at the end of the push. Just curious if I’m close to 25 degrees?
Being lazier than Mitown and Seth, I use a block of scrap 2×4 with a 30 degree angle pencilled on the side as a reference.
Dave
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