Ruler trick with leather strop

[mouppe]

Several years ago I bought a second-hand Lie Nielsen #7 in excellent condition. The seller told me that he had put a tiny back bevel on the back as per the David Charlesworth method and for many years I continued to sharpen the blade this way.

However over time the back bevel became smaller and smaller. At the same time I started doing my final polishing with a leather strop after using an 8000 grit waterstone.

Today I had reason to remove a lot of metal due to a very large nick in the blade. This took out the remainder of the back bevel. Now it seems to me that using the leather strop on the back of the blade would have the same effect as the ruler trick because of the tiny mushrooming effect of the leather and this seems to be the example with my other blades.

I don't want to start irrelevant arguments about the efficacy or history of the ruler trick but am wondering about whether I am right in thinking this about the effect of the strop on the back of the blade.

 

[Trafalgar]

You're right. This phenomenon is also apparent on firm rubber strops. Polishing right at the cutting edge, both front and back, has been accessible to woodworkers as long as strops have been used -- a quite considerable length of time. That said, the edge off one's finest stone is rarely not a serviceable one.

 

[Jacob]

Yes that's it. It's not about bevels it's about polishing up the critical working surfaces at the point of most (friction) stress and is extremely ancient.

 

[bugbear]

Several years ago I bought a second-hand Lie Nielsen #7 in excellent condition. The seller told me that he had put a tiny back bevel on the back as per the David Charlesworth method and for many years I continued to sharpen the blade this way.

However over time the back bevel became smaller and smaller. At the same time I started doing my final polishing with a leather strop after using an 8000 grit waterstone.

Today I had reason to remove a lot of metal due to a very large nick in the blade. This took out the remainder of the back bevel. Now it seems to me that using the leather strop on the back of the blade would have the same effect as the ruler trick because of the tiny mushrooming effect of the leather and this seems to be the example with my other blades.

I don't want to start irrelevant arguments about the efficacy or history of the ruler trick but am wondering about whether I am right in thinking this about the effect of the strop on the back of the blade.

Yes, a strop tends to round the bevel.

However, a blade as flat as LN one shouldn't need any special tricks - just polishing "flat" should get you right to the end, no trouble.

The ruler trick (micro-back-bevel) is much more essential when the back of the blade is in poor condition.

BugBear

 

[Trafalgar]

True Bugbear. The big mystery is why somebody would care to have cutters in such poor condition that this technique would be required in the first place. Light pitting is easily rectified with modern abrasives. Thousands of dollars invested in tools, shop space, etc. and the line is drawn at cutters for hand planes? Never has made sense to me. Even vintage steel in pretty darned good condition is not that hard to find - certainly not in such bad condition that introducing a back-bevel in more or less perpetuity is required.

 

[Jacob]

Several years ago I bought a second-hand Lie Nielsen #7 in excellent condition. The seller told me that he had put a tiny back bevel on the back as per the David Charlesworth method and for many years I continued to sharpen the blade this way.

However over time the back bevel became smaller and smaller. At the same time I started doing my final polishing with a leather strop after using an 8000 grit waterstone.

Today I had reason to remove a lot of metal due to a very large nick in the blade. This took out the remainder of the back bevel. Now it seems to me that using the leather strop on the back of the blade would have the same effect as the ruler trick because of the tiny mushrooming effect of the leather and this seems to be the example with my other blades.

I don't want to start irrelevant arguments about the efficacy or history of the ruler trick but am wondering about whether I am right in thinking this about the effect of the strop on the back of the blade.

Yes, a strop tends to round the bevel.

However, a blade as flat as LN one shouldn't need any special tricks - just polishing "flat" should get you right to the end, no trouble.

The ruler trick (micro-back-bevel) is much more essential when the back of the blade is in poor condition.

BugBear

In reality what most people do (without even thinking about it) is put more pressure towards the cutting edge when "flattening" or stropping the face. This effectively forms a shallow bevel - hardly noticeable but it develops until you get an old tool with a distinctly convex face. No need to panic this is fine; properly flattening the whole face is pointless madness.

 

[Trafalgar]

I don't think it's a matter of madness as most cutters these days come already flat. The worst Stanley/Record iron I've personally ever owned took twenty minutes or so to flatten and polish right to the edge.

Flat is this -- flat enough that the burr will flip back to the beveled edge in a few strokes on a fine stone. If one can chase the burr without lifting on a reasonably well kept stone the cutter or chisel is essentially flat. If the burr won't flip back on the stone then one is faced with a bit of a problem. The strop might be an immediate fix it but over time will worsen the problem to the point the strop no longer has an affect on the burr. At that point, the cutter is out-of-flat and the only thing that will allow the burr to be chased is to flatten the cutter or lift it on the stone or strop which over time continues to make the problem worse. Robert Wearing has an excellent line drawing of this phenomenon in one of his books.

 

[G S Haydon]

"Flat is this -- flat enough that the burr will flip back to the beveled edge in a few strokes on a fine stone. If one can chase the burr without lifting on a reasonably well kept stone the cutter or chisel is essentially flat. If the burr won't flip back on the stone then one is faced with a bit of a problem. The strop might fix it but over time will worsen the problem to the point the strop no longer has an effect on the burr. At that point, the cutter is out-of-flat and the only thing that will allow the burr to be chased it to flatten the cutter or lift it on the stone or strop which over time continues to make the problem worse. Robert Wearing has an excellent line drawing of this phenomenon in one of his books."

+1

 

[Cheshirechappie]

With final polishing on a stone of about 8000 grit, it might be worth a try WITHOUT stropping. Just take the burr off by alternate strokes on the bevel and flat sides on the polishing stone. It won't take much; a polishing stone won't raise much of a burr, if any.

My first experience of stropping, many years ago, was that it dulled, or dubbed, a fresh edge. I strongly suspect that part of the reason for this was that I stropped on a loose piece of leather rather than on a piece of leather glued to a firm substrate. I'm now pretty convinced that strops should be as firm as possible - some people advocate a piece of MDF or similar, either plain or dressed with a very fine abrasive. I'm also fairly convinced that whilst they have definite benefits if taking off the wire edge raised on a honing stone (such as a fine India oilstone or 1000 grit diamond hone), they are detrimental to the edge from a fine polishing stone.

Some of the old craftsmen used to strop on the palms of their hands, held open to stretch the skin. Charles Hayward (among others) publicised this method in print, and it has the strong advantage of cheapness and availability; it's also quite hard to lose your strop in the shavings on the bench.

 

[Phil Pascoe]

I usually use my jeans, as they are usually dirty enough to be slightly abrasive.

 

[matthewwh]

The ruler trick isn't a last ditch option to overcome failings in the back of the blade (although it does that too).

It's an entirely superior technique that replaces the flat back on plane irons and should be used as a first option all the time.

Surely there must be more people than DC and myself who have grasped the concept by now...?

OP, yes, a strop will focus on the very cutting edge for the reasons you state, there isn't enough material being removed to affect the geometry of the edge and any rounding will be removed by honing before it has chance to develop into anything visible or significant.

 

[mouppe]

With final polishing on a stone of about 8000 grit, it might be worth a try WITHOUT stropping. Just take the burr off by alternate strokes on the bevel and flat sides on the polishing stone. It won't take much; a polishing stone won't raise much of a burr, if any.

My first experience of stropping, many years ago, was that it dulled, or dubbed, a fresh edge. I strongly suspect that part of the reason for this was that I stropped on a loose piece of leather rather than on a piece of leather glued to a firm substrate. I'm now pretty convinced that strops should be as firm as possible - some people advocate a piece of MDF or similar, either plain or dressed with a very fine abrasive. I'm also fairly convinced that whilst they have definite benefits if taking off the wire edge raised on a honing stone (such as a fine India oilstone or 1000 grit diamond hone), they are detrimental to the edge from a fine polishing stone.

Some of the old craftsmen used to strop on the palms of their hands, held open to stretch the skin. Charles Hayward (among others) publicised this method in print, and it has the strong advantage of cheapness and availability; it's also quite hard to lose your strop in the shavings on the bench.

For years I didn't use a strop but I have found it helps improve the edge a little. My strop is a 1" piece of wood with a thin piece of leather glued to it charged with green compound.

 

[Cheshirechappie]

Polishing stones and strops do vary a bit. The first rule of sharpening (well, basically the only one worth noting) is to go with what works for you - if stropping gives you a better edge than your polishing stone, stick with the strop!

 

[Jacob]

The ruler trick isn't a last ditch option to overcome failings in the back of the blade (although it does that too).

It's an entirely superior technique that replaces the flat back on plane irons and should be used as a first option all the time.

Surely there must be more people than DC and myself who have grasped the concept by now...?

OP, yes, a strop will focus on the very cutting edge for the reasons you state, there isn't enough material being removed to affect the geometry of the edge and any rounding will be removed by honing before it has chance to develop into anything visible or significant.

It's what everybody did one way or another, with variations, before the modern obsession with flatness caught on. Though the ruler isn't necessary of course. They merge into one another. Stropping is polishing (which improves the cut) but if you use a paste it turns into more significant material removal. It 's hard to say where one ends and the other begins. They all involve a slightly rounded bevel (so what?) unless you polish the whole face flat every time - which would be totally impractical.
I wonder if it'll ever end , this obsessive attention to trivial details. :lol: :lol:

 

[woodbrains]

Hello,

Removing the wire edge with the palm of the hand is NOT stropping! The two should not be confused, but often are. Does anyone really think that a few strokes of a joiners hand, alternated on bevel and face, actually imparts any sharpening effect? Did Hayward actually note this technique as anything other than a way of removing the wire edge? I'd be surprised if he did.

I also see the benefit of the ruler trick, but am now tired of explaining about the wear bevel being removed by back bevelling, more effectively, and with less steel removal than not. But hey ho!

Mike.

 

[MIGNAL]

Yes it is Woodenbrains. Some of us have done mighty hard physical work throughout our lives. I rate my palm at about 800G. It used to be 120G but I retired 6 months ago. That and the Oil of Olay.

 

[Jacob]

Hello,

Removing the wire edge with the palm of the hand is NOT stropping! The two should not be confused, but often are. Does anyone really think that a few strokes of a joiners hand, alternated on bevel and face, actually imparts any sharpening effect?.....

Yes it is and yes it does - it polishes the edge adjacent to the bevel and may remove traces of burr.
What two things are confused? We know you are!

 

[woodbrains]

Hello,

Put a bit of chrome oxide in your oil of ulay and perhaps you'll be a human strip, but really!

Even Jacob just said, 'remove the burr, 'which is not stropping.

Mike.

 

[Cheshirechappie]

Hello,

Removing the wire edge with the palm of the hand is NOT stropping! The two should not be confused, but often are. Does anyone really think that a few strokes of a joiners hand, alternated on bevel and face, actually imparts any sharpening effect? Did Hayward actually note this technique as anything other than a way of removing the wire edge? I'd be surprised if he did.

I also see the benefit of the ruler trick, but am now tired of explaining about the wear bevel being removed by back bevelling, more effectively, and with less steel removal than not. But hey ho!

Mike.

Well, depends on the precise definition of 'stropping', I suppose. And no, I don't think Hayward did suggest that using the palm of the hand (which is a sort of leather, when all's said and done!) had any sharpening effect, it was just about removing the last of the wire edge.

In 'Teach Yourself Carpentry' on page 27, Hayward shows a photograph (Figure 13) of a craftsman (probably himself) drawing a plane iron across his palm. The caption reads, "Stropping the Cutter - It is drawn across the hand, first one side and then the other."

On page 26, he writes, "It is then stropped either on a piece of leather glued to a flat board, or by drawing it across the left hand, first one side and then the other (Fig.13). It should be noted that it is of the utmost importance that the back is not dubbed over either on the stone or on the leather strop."

Which doesn't really contradict anything that's been said so far.

 

[Jacob]

Hello,

Put a bit of chrome oxide in your oil of ulay and perhaps you'll be a human strip, but really!

Even Jacob just said, 'remove the burr, 'which is not stropping.

Mike.

It is stropping if you do it in a stropping sort of way.