Microbevel or not

[Joe Cowan]

I was just wondering how many put a microbevel on their plane irons/chisels, or just finish the primary bevel to the sharpness level needed.

[Jessica Pierce-LaRose]

I tend to hollow grind the majority of my tools on a 6" grinder, so I don't bother much with a microbevel anymore. Before I started using that, I tended to microbevel on harder steels or thicker blades, just to make the job a little quicker.

I still do it from time to time, particularly if I'm trying to squeeze out a couple more sharpenings before returning to the grinder. Since I tend to freehand hone, I generally only microbevel on my higher grit stones - makes that part of the sharpening go a little easier, but since my 1K still chews through material faster, I avoid getting an increasingly steeper microbevel each time I sharpen by returning to the original bevel each time I hit the coarse stone.

[John Coloccia]

I don't bother with micro bevels or hollow grinds anymore. I just strop a lot. In fact, I sold off much of my sharpening gear. I simply got tired of all the rituals.

[David Weaver]

I was just wondering how many put a microbevel on their plane irons/chisels, or just finish the primary bevel to the sharpness level needed.

I do it on smoothing planes. Usually. I do something similar freehand to chase the burr on the coarse plane irons. But I don't do it on chisels.

[Chris Griggs]

I typically free hand hone right on the hollow grind. Sometimes I will lift up and micro bevel a bit on my higher grit stones, or if I am refreshing an edge on a strop I will often lift a tad higher then the hollow grind. The other situation where I sometimes micro bevel is if my hollow as been mainly honed out and I don't feel like regrinding at the moment. In those case I will sometimes freehand hone a micro bevel starting at my 1k stone - I can get a few extra rehonings out of an edge that way before going to the grinder. Of course, after a few rehonings on the MB it grows or rounds over and then its back to the grinder and honing in the primary hollow grind.

[Jessica Pierce-LaRose]

I don't bother with micro bevels or hollow grinds anymore. I just strop a lot. In fact, I sold off much of my sharpening gear. I simply got tired of all the rituals.

Good point there - I still hollow grind because 5 minutes at the grinder makes free-hand honing a little quicker and much more fool-proof when I'm not paying as much attention as I should, but with my chisels, the more I strop, the less I have to hone, although I do tend to get to a point where stropping has diminishing returns, (but that may be my stropping set up or technique) and it's back to the stones. I think stropping was one of the most eye opening things in sharpening for me.

Out of curiosity, what's your stropping set-up, John?

[Michael Fross]

I use a grinder to create the primary bevel (normally 25 degrees). I freehand sharpen by lifting up slightly to create a secondary bevel on my first stone (1000) and then lift slightly more on my last stone (16k). You end up removing very little material so its fast. For example, on the 16k stone, it only takes about 10 seconds.

I've tried lots of techniques, but for me this is the fastest. Takes about a min to resharpen unless I have to hit the grinder again.

I love hearing all the great techniques. There is certainly more than one way to skin this cat.:-)

Michael

[John Coloccia]

Good point there - I still hollow grind because 5 minutes at the grinder makes free-hand honing a little quicker and much more fool-proof when I'm not paying as much attention as I should, but with my chisels, the more I strop, the less I have to hone, although I do tend to get to a point where stropping has diminishing returns, (but that may be my stropping set up or technique) and it's back to the stones. I think stropping was one of the most eye opening things in sharpening for me.

Out of curiosity, what's your stropping set-up, John?

A piece of leather scrap from Tandy glued to a piece of MDF. I think I have about $.50 invested. LOL. I keep that charged with Simichrome and I don't worry about cutting into it too much. I'm on my second or third one. When it gets beat up, I toss it out and build a new one for $.55 (have to account for inflation). I also have a nice Butz strop that I paid some coin for and I do try to keep that one nice. I keep one side charged with Simichrome, and the other side dry.

Then I have a couple of Spyderco ceramic stones for when stropping stops working. A few swipes freehand on that and I'm back in business. When all that stops working, I touch it for a second on the Worksharp, and I'm back in business.

My Butz
DSC02252.JPG

I guess I lied about the other one. It's a piece of Mahogany. Probably quartersawn Honduran. If you use rift saw, or African mahogany (Khaya), it will ruin all of your tools. Be sure to use the right shade of leather. To light and it will leave scratches. Too dark and your edge will be fragile. Ask where the cow came from. Cows from the US are the best, but lately all I've been able to find is cows from Brazil and the leather isn't fully tanned all the way through. What is this world coming to?
DSC02251.JPG

[Derek Cohen]

Uh guys ...

... a micro bevel is a tiny bevel. It has nothing to do with angles.

... a secondary bevel is a bevel that is honed at a higher angle than the primar bevel. It is all about angles, not size.

When you hone a primary bevel directly on a hollow ground, you create a micro bevel that is coplanar with the primary bevel.

When you hone a secondary bevel on a flat or a hollow ground primary bevel, you create a micro secondary bevel.

Another common alternative is to hone on a flat primary bevel, maintaining a coplanar bevel, such as with Japanese blades.

And a last possibility is to grind/hone a convex bevel, ala the style Paul Peller promotes. This is effectively a secondary microbevel.

Clear as mud

Regards from Perth

Derek

[John Coloccia]

Uh guys ...

... a micro bevel is a tiny bevel. It has nothing to do with angles.

... a secondary bevel is a bevel that is honed at a higher angle than the primar bevel. It is all about angles, not size.

When you hone a primary bevel directly on a hollow ground, you create a micro bevel that is coplanar with the primary bevel.

Well, if you want to get technical about it, honing a hollow ground gives you a bevel that is coplanar with the plane that closes the cylindrical surface you ground into the blade...you can't be coplaner with the bevel because it's a cylindrical surface and the points don't lie on a plane

[Chris Fournier]

I dry grind on a 7" bench grinder for a hollow grind. Then I hit the stones. I will ususally put a micro bevel on everything as I find that it speeds up re-sharpening. What is a micro bevel? 2 pulls at a 2ish degree increased angle to the final 8000 grit water stone. Sharpening is not a chore to me and it all happens very quickly as I have a workable process and I've stuck to it for years.

[Derek Cohen]

Well, if you want to get technical about it, honing a hollow ground gives you a bevel that is coplanar with the plane that closes the cylindrical surface you ground into the blade...you can't be coplaner with the bevel because it's a cylindrical surface and the points don't lie on a plane

John, I find what has been written so far in this thread very confusing as posters appear to mix up secondary bevels with microbevels. Perhaps a few definitions might unravel what they are meaning to write?

The thing is, you automatically add a microbevel when honing on a fresh hollow grind. Whether this is coplanar or secondary is unclear in any of this posts.

Regards from Perth

Derek

[Adam Cherubini]

Hi Joe-

I think it's a mistake to seek a consensus on issues like this one. My take is that for thick tools, honing an entire bevel is a waste of time and effort. Guys who do it seem to do it for reasons of expedience for their sharpening technique. The chisel doesn't need a fully polished bevel to cut (but read below carefully).

I'll defer to Derek on the naming. What I do is grind low- like 20 degrees, then hone a small area at the cutting edge to the angle I prefer.

Only thing I can add is that the area behind the edge is somewhat important. For those of you who hollow grind, the chisel thinks that rough ground area IS the bevel. From the chisel's point of view, you hollow grinders are creating secondary bevels (using Derek's terminology). And the hard line that foams between the bevel at the edge and the hollow is a terrible stress concentration. I know some of us hone the hollow completely away- which is fine.

I suspect one of the major failure modes of edges involves bending. Supporting the edge behind the honed tip is important. Reducing stress concentrations behind the edge can help the tool react the stress we apply. I think the best shape scientifically is a smoothly polished elliptical (convex) bevel. That aside, here's my Given that, here's my advice:

1) if you choose to grind low and hone high (as I do), polish the ground area smooth at least. Just so happens, I think Leonard Lee arrived at this conclusion many many years ago. This was the apparent theory behind the veritias honing jig.
2) Avoid "side honing". Side honing creates scratches precisely where you don't want them....like perforations on a paper towel roll. If you really prefer side honing, polish your bevel to a high hone for maximum strength.
3) Reducing the bevel angle of a chisel used for chopping both weakens the edge but also reduces bending stress (making the edge last longer). For each chisel, there is a "sweet spot". My belief is that widths of chisels (and the radius of a cambered plane iron) affects the tool's strength. Therefore, each tool in my shop has a slightly different angle. My wide chisels typically have lower bevel angles than the narrow ones. Coincidentally, the planes with the greatest curvature to their blades are the roughing planes and have the higher angles. BUT- planes with higher pitches need higher bevel angles because the bending stress is that much greater.

Conclusion:
You inevitably must decide how to sharpen based on your skill, equipment, and projects. I think the science I wrote about above is helpful, but I think it's up to you to fit it into your sharpening regime, and not vice versa. The single biggest thing I learned about sharpening in last 5 years I learned from my friend Warren Mickley- sharpening should be quick and easy- so easy that you can do it every 20 minutes if need be without much interruption. I used to look at it as something I did between projects. Now it's integral with my bench work. I think Warren can touch up an edge at his bench in under a minute.

[John Coloccia]

John, I find what has been written so far in this thread very confusing as posters appear to mix up secondary bevels with microbevels. Perhaps a few definitions might unravel what they are meaning to write?

The thing is, you automatically add a microbevel when honing on a fresh hollow grind. Whether this is coplanar or secondary is unclear in any of this posts.

Regards from Perth

Derek

People normally use "microbevel" to mean a small secondary bevel. The two terms are normally used interchangeably. The only time it really needs a distinction is when you're talking about mortise chisels, because they may have a very shallow primary bevel, and a very steep secondary bevel....which is not "micro" by any means. It's usually a significant, stout secondary to keep the edge from falling apart.

I don't think most people would consider honing a hollow grind as a microbevel. Usually, that term is reserved for a small, secondary bevel, even though you're right that honing a hollow does indeed form a small bevel that would otherwise not be there.

[Jessica Pierce-LaRose]

[QUOTE=John Coloccia;2020545

I guess I lied about the other one. It's a piece of Mahogany. Probably quartersawn Honduran. If you use rift saw, or African mahogany (Khaya), it will ruin all of your tools. Be sure to use the right shade of leather. To light and it will leave scratches. Too dark and your edge will be fragile. Ask where the cow came from. Cows from the US are the best, but lately all I've been able to find is cows from Brazil and the leather isn't fully tanned all the way through. What is this world coming to?
[/QUOTE]

Wait, I'm dumb - are you being funny or serious here? I guess I can see poor quality leather being a problem (but if it's not tanned, doesn't it rot eventually?) But how does the wood behind the leather matter other than being a stable substrate?