Did oldtime craftsman flatten their plane irons?

[Frederick Skelly]

This morning I found myself wondering how much of our sharpening ritual is modern "druthers". Specifically, did our ancestors spend much time flattening and polishing the back of plane irons and chisels to a mirror finish? Or did they get them "sorta flat", polish to maybe the equivalent of 220 grit, and call it good enough?

I'd sure enjoy a history lesson on this from George, Warren or anyone else who knows old techniques. (Wish Dave was still here - he'd also have something fascinating to tell us. Sigh.)

Thanks guys!Fred

[Kees Heiden]

Over on the ukworkshop forum there is a guy named Jacob. He is running a holy war against flat backs on chisels and plane irons. He never gets tired of learning everyone around that flattening backs is a modern fad.

I would agree with him if I didn't alwas acquire irons with pitting and heavy dubbed edges on the back. So I continue polishing backs, but keep my efforts centered on the last 1/2" or so.

[Tom M King]

Not claiming to be an expert, but I have one of each, and several of some older bench planes, a couple of hundred molding planes, and a good number of other types. The one "new" plane, as in newer than made in the 1970s, is a LV shooting plane. The only plane iron I've worked on, that belongs to me, that had a flat iron back is the LV shooter.

[Phillip West]

I come from a a family of woodworkers, mostly green woodworkers making Appalachian style furniture but I have most of our family tools. Not one of the plane iron or drawknife had the back touched..bevel only.

[Brian Holcombe]

I would not be surprised if most often they simply lift the iron slightly to make a back bevel. Likely keeping it shallow enough that it could be ground past pretty quickly.

[Steve Voigt]

Most of the responses here are saying the same thing…that the old tools you own don't have flat backs, so nobody ever flattened their backs. I think this is a suspect line of reasoning. Very few of us own tools made before the late 19th century (there are some exceptions, I know), and most were made in the 20th c. Either way, nearly all were sharpened and used in the 20th century. Your prize chisel with the rounded back may have been bought new in the early 1900s, and last used and sharpened by the buyer's grandson in the 50s.

Now, if this is what you mean by "ancestors," fine. But if you mean "what did cabinetmakers and carpenters do in 1800, when there weren't any power tools to help", then I don't think you can draw any conclusions from the tools you own.

A related question that people sometimes ask is "did previous generations flatten their stones?" And most people will respond with "all the old stones I've seen are dished." But in The Joiner and Cabinetmaker, written in 1839, it states that workers would be fined for not dressing their stones and leaving them flat. Unfortunately, we don't have any plane irons and chisels that we know for sure have been unused since the early 1800s, and that we know were only used by competent workers. So we really can't say.

Anyway, I don't have an answer to Fred's question. But what I am sure of is that if we draw all our conclusions from 20th c. woodworkers, whether from looking at their tools or reading their books, we're looking in the wrong place.

[Mike Henderson]

Most of the responses here are saying the same thing…that the old tools you own don't have flat backs, so nobody ever flattened their backs. I think this is a suspect line of reasoning. Very few of us own tools made before the late 19th century (there are some exceptions, I know), and most were made in the 20th c. Either way, nearly all were sharpened and used in the 20th century. Your prize chisel with the rounded back may have been bought new in the early 1900s, and last used and sharpened by the buyer's grandson in the 50s.

Now, if this is what you mean by "ancestors," fine. But if you mean "what did cabinetmakers and carpenters do in 1800, when there weren't any power tools to help", then I don't think you can draw any conclusions from the tools you own.

A related question that people sometimes ask is "did previous generations flatten their stones?" And most people will respond with "all the old stones I've seen are dished." But in The Joiner and Cabinetmaker, written in 1839, it states that workers would be fined for not dressing their stones and leaving them flat. Unfortunately, we don't have any plane irons and chisels that we know for sure have been unused since the early 1800s, and that we know were only used by competent workers. So we really can't say.

Anyway, I don't have an answer to Fred's question. But what I am sure of is that if we draw all our conclusions from 20th c. woodworkers, whether from looking at their tools or reading their books, we're looking in the wrong place.

I have wooden coffin planes from the 1800's and the backs of the irons were not flat (irons are laminated cast steel). I've never seen an iron from an antique plane - no matter when it was used - with a flat back. The only exception was one plane I received from another woodworker, who had flattened the back.

Mike

[Steve Voigt]

I have wooden coffin planes from the 1800's and the backs of the irons were not flat (irons are laminated cast steel). I've never seen an iron from an antique plane - no matter when it was used - with a flat back. The only exception was one plane I received from another woodworker, who had flattened the back.

Mike

So what? How does this refute, in any way, what I said? Do you know when the irons were last sharpened, and by whom? If you can prove to me that the plane was made in 1800 and last used by a skilled joiner in 1820, then you've got something. Otherwise, you've got nothing.

Moreover, "from the 1800s" is meaningless, especially in the U.S. In 1810, most things of wood were still made entirely by hand. By the time of the civil war, most furniture was made in factories and most houses were framed with pre-sawn dimensional lumber. The days of people routinely thicknessing lumber by hand, as an important part of their jobs, were long gone.

[george wilson]

All of the USED plane irons from the 18th. C.,which I have seen were really rounded over on their back sides in order to make them into higher angle planes that would not tear out wood as easily. These irons were apparently honed on dished whet stones. The cutting edges were cambered also so that the corners of the irons would not leave scars on the edges of their cuts. And,some of the ORIGINAL carpentry,like chair rail moldings and stair cases and their components,were made so sloppily,they look like a drunk made them(and probably did!) And,this in rich people's houses that still exist in Williamsburg.

As I mentioned in another thread,I put a very slight camber on my own planes,so as to take off very light finishing shavings with no trace of the corners of the irons. At the very least,if I wanted a flat cut surface,I gently round the corners of my irons.

I had an argument with Peter Ross many,many years ago because he was making NEW irons with their backs hammered and ground into this rounded configuration. He was stubborn,refusing to believe what anyone else told him about anything. After many years of making these worn out looking blades,I guess he saw some 18th. C. unused irons(possibly in the Seaton Chest,and stopped making the irons rounded and blunted.

He also did not believe me when I told him that the popping noise that you get when tapping metal is caused by the peaks of the tap's teeth pressure welding to the metal you are tapping. This is a commonly known fact on machinist's fora that years later I began to visit. I wonder if he ever figured out that fact for himself? NASA was recently experimenting with a new form of welding aluminum by forcefully spinning a hardened carbide (or HSS?) steel cylinder between 2 sheets of the metal that are in close contact. It gets so hot from the friction,the metal sheets' edges are melted and stirred together. A friend of mine runs a machine shop there(or used to. They have taken to farming out contractors to use in the NASA shops). Sometimes,my friend says,he will spend many hours programming a CNC machine,then turning out the part in 20 minutes!

[Warren Mickley]

I have wooden coffin planes from the 1800's and the backs of the irons were not flat (irons are laminated cast steel). I've never seen an iron from an antique plane - no matter when it was used - with a flat back. The only exception was one plane I received from another woodworker, who had flattened the back.

Mike

I think you are talking about stuff from the dark ages here, Mike. Hand work on furniture was declining already in 1825. I remember some years ago trying to convince David Weaver that the antique plane he just bought might have been used by a carpenter, a farmer and a handyman in the time since it was used by a fine craftsman, if ever. It would be helpful to find tools fresh from an 18th century cabinetmaker from London or Philadelphia, but the very few that are around have usually been used by others in the last 216 years.

The evidence from the 18th century is that they did nice work, and I can't see doing that with less than well kept tools. They also had fine oil stones. So I would suggest backs flattened enough to lay on a fine stone.

One thing about "flattening backs" the average joiner or cabinetmaker had four or five bench planes, and he did an awful lot of planing and sharpening before wearing a plane iron down to nothing. So although flattening was probably a chore, it was rather different from today when a guy could find himself flattening a plane iron every other month., what with "replacement blades" and multiple smoothing planes etc.

When I was young I did some experiments with the jack plane to see if it really needed to as well sharpened as say a trying plane. I tried using a coarse stone only, using a coarse and medium stone only, using a coarse and lightly refining with the fine stone , etc. What I found was that using the same routine as I used for the finer planes contributed enough to edge longevity to justify the few extra seconds. The ease of using a sharper tool was a bonus.

[Mike Henderson]

I think you are talking about stuff from the dark ages here, Mike. Hand work on furniture was declining already in 1825. I remember some years ago trying to convince David Weaver that the antique plane he just bought might have been used by a carpenter, a farmer and a handyman in the time since it was used by a fine craftsman, if ever. It would be helpful to find tools fresh from an 18th century cabinetmaker from London or Philadelphia, but the very few that are around have usually been used by others in the last 216 years.

The evidence from the 18th century is that they did nice work, and I can't see doing that with less than well kept tools. They also had fine oil stones. So I would suggest backs flattened enough to lay on a fine stone.

One thing about "flattening backs" the average joiner or cabinetmaker had four or five bench planes, and he did an awful lot of planing and sharpening before wearing a plane iron down to nothing. So although flattening was probably a chore, it was rather different from today when a guy could find himself flattening a plane iron every other month., what with "replacement blades" and multiple smoothing planes etc.

When I was young I did some experiments with the jack plane to see if it really needed to as well sharpened as say a trying plane. I tried using a coarse stone only, using a coarse and medium stone only, using a coarse and lightly refining with the fine stone , etc. What I found was that using the same routine as I used for the finer planes contributed enough to edge longevity to justify the few extra seconds. The ease of using a sharper tool was a bonus.

We have two hypotheses here:

1. Old time woodworkers did not flatten the backs of their plane irons.

2. Some old time woodworkers did flatten the backs of their plane irons.

We have lots of examples of old plane irons that were not flattened, which supports hypothesis number 1.

I have not heard of any examples of old plane irons that have had the black flattened.

Now, absence of evidence is not evidence of absence, but until we find some examples to support hypothesis number 2 we have to question whether it's true or not.

Mike

[Tony Zaffuto]

Over on the ukworkshop forum there is a guy named Jacob. He is running a holy war against flat backs on chisels and plane irons. He never gets tired of learning everyone around that flattening backs is a modern fad.

I would agree with him if I didn't alwas acquire irons with pitting and heavy dubbed edges on the back. So I continue polishing backs, but keep my efforts centered on the last 1/2" or so.

Jacob argues with everyone and occassionally himself! He hates modern "dosh", and has been known to fashion an axe head out out of a stone to hew a timber just to prove one does not need anthng made recently.

[Patrick Chase]

Over on the ukworkshop forum there is a guy named Jacob. He is running a holy war against flat backs on chisels and plane irons. He never gets tired of learning everyone around that flattening backs is a modern fad.

I would agree with him if I didn't alwas acquire irons with pitting and heavy dubbed edges on the back. So I continue polishing backs, but keep my efforts centered on the last 1/2" or so.

I think that some people conflate "flat" and "smooth". There is also the question of "local flatness" vs the sort of overall flatness that LN and LV now achieve.

IMO smoothness matters a lot - you can only have a truly sharp edge when two smooth surfaces intersect. If either surface is rough then the edge will be ragged in equal degree. Note that I say "smooth surfaces" where many authors instead say "smooth planes". Planarity (a.k.a. "flatness") doesn't impact sharpness. Also, the amount of the edge that needs to be smooth is very small - all that matters is that scratches don't compromise the edge.

Local crosswise (parallel to the cutting edge) flatness immediately behind the edge is critical in anything with a double iron. If you don't have at least that then good luck getting the cap iron to mate well enough to avoid clogging. Charlesworth's "ruler trick" is basically taking advantage of this fact - he dubs the face a bit lengthwise while preserving crosswise flatness.

Beyond that it's a matter of degrees, specifically whether the blade is out far enough to compromise cut depth/profile or prevent bedding with a reasonably tight cap iron (though note that in a BD plane this is more a function of the back than of the face). IMO you absolutely do not need total flatness for either of those.

So taking all of that together, I don't spend much effort flattening blade faces other than in the immediate vicinity of the edge. When I encounter a non-flat blade my usual reaction is to reach for a thicker ruler (or piece of shim stock), within reason. I appreciate the flatness of my LV/LN blades, but also recognize it as a form of market-driven fetishism that doesn't really impact performance.

[Stanley Covington]

I think that some people conflate "flat" and "smooth". There is also the question of "local flatness" vs the sort of overall flatness that LN and LV now achieve.

IMO smoothness matters a lot - you can only have a truly sharp edge when two smooth surfaces intersect. If either surface is rough then the edge will be ragged in equal degree. Note that I say "smooth surfaces" where many authors instead say "smooth planes". Planarity (a.k.a. "flatness") doesn't impact sharpness. Also, the amount of the edge that needs to be smooth is very small - all that matters is that scratches don't compromise the edge.

Local crosswise (parallel to the cutting edge) flatness immediately behind the edge is critical in anything with a double iron. If you don't have at least that then good luck getting the cap iron to mate well enough to avoid clogging. Charlesworth's "ruler trick" is basically taking advantage of this fact - he dubs the face a bit lengthwise while preserving crosswise flatness.

Beyond that it's a matter of degrees, specifically whether the blade is out far enough to compromise cut depth/profile or prevent bedding with a reasonably tight cap iron (though note that in a BD plane this is more a function of the back than of the face). IMO you absolutely do not need total flatness for either of those.

Patrick:

A well stated common-sense approach.

I would add that, as much as we try, it is practically impossible to obtain true planar flatness using imperfect stones and irregular hand movement, which is the best we have to work with. It is difficult even with very precise machinery. As much as we want perfection (or not as in the case of the flaming anarchists), the best we can hope to achieve is a compromise between sharpness and speed. For woodworking purposes, and where stropping is used (a procedure I follow religiously) close is good enough, IMO.

My argument has been that, while the old timers in the West had unimpressive stones, their surviving work is testimony that they knew how to get a pretty sharp edge, and the more accomplished of them would know enough to try to keep their stones flat and their blades (at least the last few millimeters of the blade) relatively flat and with uniform scratches. Efficiency would demand this much of their attention at least.

Two cents.

Stan

[Patrick Chase]

My argument has been that, while the old timers in the West had unimpressive stones, their surviving work is testimony that they knew how to get a pretty sharp edge, and the more accomplished of them would know enough to try to keep their stones flat and their blades (at least the last few millimeters of the blade) relatively flat and with uniform scratches. Efficiency would demand this much of their attention at least.

Two cents.

Stan

Yeah, it's certainly easier to maintain a sharp edge if the face and your stones have complementary shapes, and "locally flat" (the last couple mm as you say) is probably the most practical/efficient way to get there. That's what I do FWIW.

I think it's important to recognize that in that case flatness is a means (to efficient maintenance) rather than an end, though.