Not getting even secondary bevel

[Dan McGonigle]

I’ve found I don’t get a consistently even secondary bevel when honing chisels with my Veritas MK. II. I set my primary with 220 (if needed), 400, and 800 paper. Then to 1000g waterstone, raising a wire edge with each grit. I then switch to the higher micro bevel setting and pull a few strokes on my 6000g and then 8000g stones. I typically have to apply pressure to the corners of my chisel to get it honed. Any ideas as to why this is happening?

[Bob Jones 5443]

That's a mystery to me, Dan. It largely sounds like you're doing the right stuff.

Let me bring in some terminology.

To me, the "primary" bevel is achieved on the grinder, or from the manufacturer, or –– sometimes –– on your own 220 grit stone (or paper, I suppose). That bevel is usually 25º, but could be steeper in some cases (like mortise chisels, maybe). This grinding will leave a substantial wire edge.

NOTE: None of this beveling begins until the back is flat and polished to 8000 grit, so don't take off the wire edge with the grit you used in an intermediate step. Doing that will expose the polished back to the rough grits. If you must take off the wire edge, do it on the 8000 stone.

The "secondary" bevel brings the chisel closer to the working angle of the edge. For me, for most tasks, that is 33º. I get this on the 1000 stone (only). Because it's 8º steeper than the primary, it only reaches the last millimeter or so of the cutting edge (no more), and once you have an even wire edge, as you say, you've got the secondary bevel. I can get the wire edge across the edge with usually four to eight strokes on the 1000 stone. Substantial pressure across the width of the edge! I usually just leave the wire edge as it is, because I don't want to touch the back of the chisel with a 1000 stone. But if I have to, I'll ease it off with the 8000 stone. I typically don't bother.

The working or "tertiary" bevel, in my shop, is just 2º steeper that that: 35º if my secondary is 33º. For this I use only the 8000 stone: no other, even though the last stone was a 1000. This time I'm whisking off the finest little line (<0.5 mm) and getting a tiny wire edge. I can usually get the wire edge from the 35º bevel with three or four light strokes on the 8000 stone (just kiss the stone). Only now do I ease off the wire edge, on the 8000 stone.

The a chisel gets dull in use, the entire resharpening process –– from bench, to sharpening station, back to bench –– takes maybe five minutes, including all the fussing with the water and flattening the stones.

Sharpening threads here are kind of radioactive. Everyone has the One True Method. Certainly I do :). But for me the mystery of sharpening went away for good when I committed to studying one expert's method in detail, closely following every step. Once I committed that method to practice, I have never failed to quickly achieve an outstanding edge quickly and confidently. I wish I could say that about my other woodworking results.

I don't think it matters which guru you choose to emulate. Cosman certainly makes his method approachable with his folksy teaching process. My favorite by far is David Charlesworth. Some Yankees may not have the patience for his erudite British diction, but I find his precision highly instructive and inspiring. Just make sure your expert of choice knows what he or she is doing and explains it fully.

[Jim Koepke]

Sharpening threads here are kind of radioactive. Everyone has the One True Method. Certainly I do :).

What is the Buddhist saying? "There are many paths up the mountain to reach its peak."

jtk

[Scott Winners]

:popcorn: Sharpening is a process. On the stones I have recently started pulling the iron towards me instead of pushing it away from a chairbuilding book I read. Doesn't mean it will work for you. Are you using the V MkII all the way through your process?

Ultimately, if you are satisfied with your sharpness and your output the test of us can pound salt.

[Rob Luter]

Are your stones flat? Is the back of your chisel flat? Is your primary bevel flat and square? Using the appearance of the secondary bevel against the primary to gauge "consistency" can be misleading. Been there, done that. It will only look perfect if every other variable is perfect. Nothing is usually perfect. I used to use a MKII system. They work great. Turning the eccentric roller back to gain the secondary bevel is a great feature, That said, if the relationship between OD and ID centerlines isn't perfectly parallel, the secondary bevel looks off. They have the same issue with the narrow blade jaws.

What's important is how the chisel works. Are you getting the functionality that you want?

[Jim Matthews]

^^^
This. If the stones are low in the middle, only the edges will touch down.

[James Pallas]

First I want to say that the Mark II is a good tool. You answered your own question inadvertently I think. You stated that you push harder on one side to get the corners. Once that is done the geometry is changed. The tool is good but it is not a ridged set up like a surface grinder. Human intervention is involved. The human eye can easily see a couple of thousand differences. You can see a hair in your soup for instance. On two freshly stoned surfaces that can look huge. If the tool cuts good stop worrying about it. I’ve said this before, all of these jigs allow for human influences, the angle may go in the other direction the next time you sharpen up.
Jim

[Curt Putnam]

Not being an expert, I will, of course, chime in.

The 1st thing to remember is that the honing guide's purpose is to help you hold a precise angle while honing. You must hold the chisel such that it remains square while the guide controls the angle. You can still radius a blade with the flat roller by putting pressure on one corner and then the other. So I will suggest that your first task is to examine your techique.

Stones that are not flat can also cause the same results you are getting.

Summary: Flat stones, chisel installed squarely, clamped evenly and held with equal pressure on both sides

[Dan McGonigle]

I try to flatten my stones regularly, maybe not as often as as should for perfect flatness though. Maybe I’m not applying enough hand pressure while setting the primary bevel and thats causing the edge to become out of square. I don’t really apply much pressure at all, just enough to keep the tool in contact and the jig to move smoothly without any chatter or accidentally tilts or movements.

My sharpening process isn’t as involved as other. 25 degrees through the coarse grits, if needed, then 1000g stone until I raise a wire edge. At that point, I remove the wire edge, then the micro bevel adjuster, and move to the 6000 8000 stones. The level of sharpness I achieve is to my satisfaction. I just want to make sure I’m getting the cutting bevel honed evenly across the edge.

I’ve read others having problems with the MKII as a result of uneven tightening of the clamping mechanism. Since reading about that, I have paid special attention to tightening as evenly as possible.

[Curt Putnam]

don’t really apply much pressure at all, just enough to keep the tool in contact and the jig to move smoothly without any chatter or accidentally tilts or movements.

Since you are tightening the clamp screws evenly and move with just enough pressure to hold the tool flat and let the stone do the cutting then that leaves stone flatness as the culprit. Start with a flat back and create a new primary (no secondary) and a known square edge and then concentrate on how you hold the guide with chisel as you hone a new secondary. Do this on freshly flattened stones. Check under magnification every few strokes so you can see if things are going off the rails.

[Gary Focht]

You inspired me to break out my Mark II on my chisels. I had been trying to learn to freehand sharpen. I used the narrow guide - so much easier than the original clamping head. I never could keep chisels square with it - especially the narrow ones. I honed the primary at about 23 degrees (head set to yellow, length guide set on 15 green). Then I set the roller for a micro bevel and honed on my superfine diamond. Then I unicorned. Very pleased with the results.

Chisel end and bevel is pretty darn square. Maybe a hairs width out of square on my 1” chisel. Maybe. I think I may just continue using the guide. It will be fast and easy to rehone and unicorn.

[Rob Mahar]

I'll throw in my guess as someone who has a mk2 guide (although I think this would be for any guide and the mk2 has a wider roller than most).

My first thought is that when you are setting your primary bevel on the coarse grits, you are accidentally adding a bit of camber/curve to the blade edge. It doesn't take much uneven pressure with coarse grits to change the shape. When you move to the finer grits that cut slower, you are only seeing the center get honed as the edges are slightly off the stone from the camber until you either work down to a flat edge or apply pressure to the edges.

You can check this by holding the blade up to a square or on a flat surface and looking for light along the edges before you move to the secondary bevel. It can take some time to get the feel for even pressure across the blade. For me that means lighter pressure than I think and keeping my fingers in near the center and away from the edges.

Clamping the blade in unevenly will usually show a skew across the edge where one corner gets honed more than the opposite. Just having the center get abraded and not the edges points to either the edge or the stone being curved.

[Gary Focht]

One thing I forgot to mention in my earlier reply. I prefer to have the blade facing me and I put my thumbs on the blade. Not sure it makes any difference, but it could affect the ease with which you apply pressure on the chisel and how you distribute that pressure.

[jeff sokoly]

I don’t usually post much but I enjoy learning. I also learn the hard way. I have the mk2 and I get excellent results now. I did however have problems early on by accidentally using the camber roller instead of the straight roller. I couldn’t figure out why the bevels weren’t right and found that I was using the camber roller. I know, nobody is that stupid. I was new to the tool and not wearing my glasses. Just a guess.

[Gary Focht]

I knew I had seen this somewhere - Lee Valley explicitly states this happens.

455490

[Phil Gaudio]

This issue has come up before: yes you are seeing an artifact of the design of this guide. One end of the roller is fixed, and one end is on an eccentric cam. When you adjust for the micro-bevel, it skews the the bevel. Would be much more expensive to design a guide that adjusted both ends of the roller. I sold mine a long time ago: happy with the LN guide at this point.

[Rob Luter]

Yup. I raised this issue in my original post in this thread. I think it has more to do with manufacturing tolerances than one end being fixed and the other on an eccentric. It seems to me the "axle" for the roller is on an eccentric at both ends. The problem occurs when the centerline of the pivots and the centerline of the portion the roller rotates on are not coincident. It doesn't take more than a couple thousands of an inch to create a mismatch where the two angles intersect at the secondary bevel. The visual is amplified by the minute distance between angles. If the secondary bevel was say 25º more than the primary instead of 1º, you'd never notice it.

I used the MKII for a number of years and found it to perform very well. That said, I too made a change to the LN honing guide and am even happier. If I want a secondary (or tertiary) bevel i just back the blade up 1/8" and call it good. It's always perfectly aligned.

In any case, the wood doesn't know the difference. Let's just get sharp and make some shavings.

[Jerome Andrieux]

I used the MKII for a number of years and found it to perform very well. That said, I too made a change to the LN honing guide and am even happier. If I want a secondary (or tertiary) bevel i just back the blade up 1/8" and call it good. It's always perfectly aligned.


Or use a shim under the wheel. Easy, repeatable, protective ...