Chisel BESS Readings, Please

[darita]

Just to update, since switching to edge trailing sharpening, I've been able to get BESS readings at or near 75 consistently, on 25 degree edges.  Under the scope, edge leading edges produce a lot more chipping, where edge trailing produces a much smoother edge.  Edge trailing also produces a much finer burr at every grit. 

[darita]

Well, I was able to get a 52 Bess reading.  After honing with a leather wheel and chromium oxide, I went to a paper wheel with 1u spray and got the 52.  I'm happy with that.  Now I think I have a protocol for chisels.

[Ken S]

Well done.

Ken

[WimSpi]

That is a particularly beautiful result. My compliments.

I myself have been a carpenter for more than 50 years. I am also going to give it a try on my 52 year old 'Nooitgedagt' chisels.

For me, sharp is enough. That's because a wood chisel can quickly become blunt again. Especially when working on construction work. You are then not able to sharpen chisels properly.
For that, you have a whetstone in your toolbox and sharpen "by hand," while working. That's how we were taught in school.

This always results in the end that the cutting edge is no longer 27 degrees*), or a corner is out, or the angle becomes slightly rounded. And with the Tormek, I make the cutting edge exact again, as it should be.

So if you're ever going to sharpen for a carpenter, it's not about "as sharp as possible," it's about "sharp" and the right sharpening angle. And: a straight cutting edge, exactly at 90 degrees.

But your test I do enjoy reading.

*) In Holland we sharpen wood chisels at 27 degrees and not at 25 degrees

[darita]

That is a particularly beautiful result. My compliments.

I myself have been a carpenter for more than 50 years. I am also going to give it a try on my 52 year old 'Nooitgedagt' chisels.

For me, sharp is enough. That's because a wood chisel can quickly become blunt again. Especially when working on construction work. You are then not able to sharpen chisels properly.
For that, you have a whetstone in your toolbox and sharpen "by hand," while working. That's how we were taught in school.

This always results in the end that the cutting edge is no longer 27 degrees*), or a corner is out, or the angle becomes slightly rounded. And with the Tormek, I make the cutting edge exact again, as it should be.

So if you're ever going to sharpen for a carpenter, it's not about "as sharp as possible," it's about "sharp" and the right sharpening angle. And: a straight cutting edge, exactly at 90 degrees.

But your test I do enjoy reading.

*) In Holland we sharpen wood chisels at 27 degrees and not at 25 degrees

I take your point respectfully, as you are a carpenter, where I am just a hobby woodworker.  I have the luxury of time. 

[Ken S]

This discussion illustrates the versatility of the Tormek. It can serve the needs of the working carpenter as well as the hobby woodworker with the luxury of time. It can serve the busy farmers market sharpener who must sharpen a hundred knives quickly as well as the home workshop sharpener who sharpens half a dozen knives infrequently.

A question for you, Wim: in the US a popular sharpening technique uses micro bevels. These are very short bevels ground a few degrees more obtuse than the primary bevel. The theory is that only a small portion of the bevel needs to be resharpened, thus saving time. Is this method commonly used in Holland?

I have two thoughts on this. 1) Part of me thinks this is unnecessary, as the Tormek does the work. 2) If resharpening is done in the field away from the Tormek, instead of starting with a small micro bevel, why not start with no micro bevel, allowing the full range of the micro bevel to be used in the field? This could conceivably allow a couple extra field sharpenings.

Thoughts?

Ken

[RichColvin]

That is a particularly beautiful result. My compliments.

I myself have been a carpenter for more than 50 years. I am also going to give it a try on my 52 year old 'Nooitgedagt' chisels.

For me, sharp is enough. That's because a wood chisel can quickly become blunt again. Especially when working on construction work. You are then not able to sharpen chisels properly.
For that, you have a whetstone in your toolbox and sharpen "by hand," while working. That's how we were taught in school.

This always results in the end that the cutting edge is no longer 27 degrees*), or a corner is out, or the angle becomes slightly rounded. And with the Tormek, I make the cutting edge exact again, as it should be.

So if you're ever going to sharpen for a carpenter, it's not about "as sharp as possible," it's about "sharp" and the right sharpening angle. And: a straight cutting edge, exactly at 90 degrees.

But your test I do enjoy reading.

*) In Holland we sharpen wood chisels at 27 degrees and not at 25 degrees

Why do you choose 27°?  Is that due to the type of wood you use?

[WimSpi]

A question for you, Wim: in the US a popular sharpening technique uses micro bevels. These are very short bevels ground a few degrees more obtuse than the primary bevel. The theory is that only a small portion of the bevel needs to be resharpened, thus saving time. Is this method commonly used in Holland?

I have two thoughts on this. 1) Part of me thinks this is unnecessary, as the Tormek does the work. 2) If resharpening is done in the field away from the Tormek, instead of starting with a small micro bevel, why not start with no micro bevel, allowing the full range of the micro bevel to be used in the field? This could conceivably allow a couple extra field sharpenings.

Thoughts?

Ken

A micro bevel was totally unknown in the Netherlands when I was learning to be a carpenter. Even (old) carpenters I worked with at the time did not know it. We learned to grind on a large spinning sandstone, which rotated through a basin of water. Somewhat similar to a Tormek.
This had to be done freehand, because as a carpenter you also had to learn to work with a steady hand. "It is beyond the craftsman's honor to use a fixed guide", it was strictly said.
Then we used Belgian whetstones to remove the burr. I still use those.

Even in the field, perhaps only in an exceptional situation was a micro bevel applied quickly, but at the next sharpening, it disappeared again.

It was through the Internet that I was recently introduced to micro bevel and I still find it very strange. I also did not miss it and do not apply it now.

[WimSpi]

Why do you choose 27°?  Is that due to the type of wood you use?


Until 1985, all chisels used by carpenters and furniture makers were made by "Nooitgedagt. Their market share was almost 80%. Only E.A. Berg still had a 15% share. All other brands were hardly available.

Nooitgedagt used Swedish steel. The same steel that was also used by E.A. Berg. That was very good steel.
Nooitgedagt determined based on their (steel) knowledge that for their chisels 27 degrees was the best. Because of Nooitgedagt's dominant market position, that became "the standard."

But we did learn that this was an average. For hardwood (such as oak, ash, beech) the advice was 30 degrees maximum and for softwood (such as pinewood), was het minimaal 25 graden.

No wood grows in Holland, to use for carpentry. All wood is imported and therefore expensive. By far the most commonly used wood here is pinewood. That is why most chisels were also sharpened at 27 degrees.

[Ken S]

Wim,

I appreciate your thoughts. I can see where having a target angle setting in mind is a good thing. However, I suspect that much of the wood joinery and fitting in my house was probably done with tools whose bevels were not exactly 27° or 25°.

I purchased my workbench in 1972 from a long retired carpenter. It was originally used in a factory to make wooden cash registers. The carpenter told me he had worked in Florida during the building boom in the 1920s. He said he could fit in a white pine door in fifteen minutes and a yellow pine door in about that many days. (I don't know how accurate his story was...)

Ken

[WimSpi]

Well, I was able to get a 52 Bess reading.  After honing with a leather wheel and chromium oxide, I went to a paper wheel with 1u spray and got the 52.  I'm happy with that.  Now I think I have a protocol for chisels.

I sharpened a chisel on the Tormek for the first time and removed the burr with the rockard felt wheel.
Then over a leather wheel, with 0.25 micron diamond polish.

But because this chisel got so short from grinding after 52 years, I had to do the deburring freehand. Grinding just barely went with the guide.
I got to BES 149.

Then I deburred with a Belgian whetstone and came up to 82 and 107.

I am not dissatisfied. But I will not reach the BESS 52 with this chisel.

[darita]

Well, I was able to get a 52 Bess reading.  After honing with a leather wheel and chromium oxide, I went to a paper wheel with 1u spray and got the 52.  I'm happy with that.  Now I think I have a protocol for chisels.

I sharpened a chisel on the Tormek for the first time and removed the burr with the rockard felt wheel.
Then over a leather wheel, with 0.25 micron diamond polish.

But because this chisel got so short from grinding after 52 years, I had to do the deburring freehand. Grinding just barely went with the guide.
I got to BES 149.

Then I deburred with a Belgian whetstone and came up to 82 and 107.

I am not dissatisfied. But I will not reach the BESS 52 with this chisel.

I'm usually happy with anything at 100 or less.