Yet another sharpening question

[Alex Liebert]

Here's a quote from Paul Sellers' blog:


Firstly, and I have already said this elsewhere, plane irons need not be dead flat at all.
Secondly, they need not be replaced with any other make of iron and certainly not thicker ones.
Thirdly, if they are bellied they need not be abraded to flatness.
Fourthly, if they are hollow they are ready to go and need minimal restorative work beyond minor abrading and polishing out along the back of the cutting edge.
There, I have just saved you an hour or two’s work.



Could someone explain his point here? If the back of the blade isn't flat, how can it be polished completely across its bottom edge?

[Stewie Simpson]

Alex; the following is from Paul Sellers blog. Forum rules prevent me from including the link. Controversial topic.Nothing further to add.


Look at this. I took a clifton plane iron from a brand Clifton plane and took a straightedge to the iron with the StaySet cap iron on the blade. The bend in the iron was then 1/32″. I did the same with a Lie Nielsen and that one bent a little more also. Loading them in a conventional plane and adding normal clampdown pressure from the lever cap they both conformed to the flatness of the bed of the frog regardless of the frog type. No plane iron is flat once the cap iron is applied with normal pressure of tightening the setscrew as tight as you can to unite the cutting iron assembly.


So, when you look at the normal pressures applied by the lever cap to the cutting iron assembly (the cap iron and cutting iron assembled), and notice that when the lever cap is indeed set and clamped down, the whole of the assembly is conformed to the frog. This is the same no matter the frog type, the maker or the thickness of irons. The only reason we need the flat face of the cutting iron to be near to flat is that it is easiest to get the cutting edge to the abrasive. Beyond that the full assembly of the iron in the plane conforms it readily to the task of planing perfection. You don’t technically or practically need dead flatness to the large flat face of your irons so I think that is quite freeing.

[Simon MacGowen]

Simply note Paul's use of "need not dead flat" or "near to flat." He is not saying any unflat iron can work.

When woodworkers demand tools satisfying tolerance to the tune of "0.0015"or even higher (and they are willing to pay the price or time to get that for their woodworking purposes), I laugh.

We have too many woodworkers willing to be led (or misled) by engineers or marketers as to how woodworking should work. Or, how wood actually works. They spend 5 times or even 10 times or more money for that premium rule or square or whatnot, although they know their work wouldn't be twice better. They put 5 hours (if not more) trying to set the tablesaw 0.001" better in tolerance even though they know they won't see any difference in their cuts, even if they achieve that.

I am a woodworker and not a slave to tolerance or flatness or squareness or straightness. If my plane iron is not dead flat, I wouldn't know it as long as my work doesn't show it.

Simon

[Pat Barry]

Simply note Paul's use of "near dead flat" or "close to flat."

When woodworkers demand tools satisfying tolerance to the tune of "0.0015"or even higher (and they are willing to pay the price or time to get that for their woodworking purposes), I laugh.

We have too many woodworkers willing to be led (or misled) by engineers as to how woodworking should work. Or, how wood actually works.


Simon
Right, engineers should stick to engineering, not woodworking, or how wood as a material actually works. We all know woodworking has been going on much longer than engineering and engineering has contributed little to woodworking, right?

[Andrew Seemann]

To take the engineering analogy further, the woodworking "gurus" have a habit of specifying things like flat, level, or square in prose without giving any tolerances.

You see phrases like "absolutely flat" or "perfectly square" or "completely level". Yet when you look at their pictures or videos, they aren't using micrometers, surface plates, ground straight edges, etc; they are squinting one-eyed at their hand planed bench with a couple of sticks (winding sticks, if you will) on it, using cheap rulers, pieces of granite, glass, that might be +/- 0.005" The "guru" might know how flat something really needs to be (or they may not, some of them are not as knowledgeable as we or they think) but they don't always remember or know how to to say it.

[Jim Koepke]

Could someone explain his point here? If the back of the blade isn't flat, how can it be polished completely across its bottom edge?

There are two dimensions involved when discussing blade flatness. One is from cutting edge to the top of the iron. This doesn't need to be perfect. Many planes that have come my way have had the tension between the cap iron and blade increased. This can cause the blade to bow and not fully mate to the frog. My choice is to undo this by working on the cap iron to decrease this extra tension. If there is too much bow in a blade, that can also be worked out with care and a little force.

The next dimension is edge to edge. If it mates to the cap iron without gaps to catch and jam shavings, then it is good enough. If one cap iron is getting swapped around on different blades, it helps if they are all 'relatively' flat, at least flat enough for a 1/4" or so to mate with the cap iron.

jtk

[Osvaldo Cristo]

Simply note Paul's use of "need not dead flat" or "near to flat." He is not saying any unflat iron can work.

When woodworkers demand tools satisfying tolerance to the tune of "0.0015"or even higher (and they are willing to pay the price or time to get that for their woodworking purposes), I laugh.

We have too many woodworkers willing to be led (or misled) by engineers or marketers as to how woodworking should work. Or, how wood actually works. They spend 5 times or even 10 times or more money for that premium rule or square or whatnot, although they know their work wouldn't be twice better. They put 5 hours (if not more) trying to set the tablesaw 0.001" better in tolerance even though they know they won't see any difference in their cuts, even if they achieve that.

I am a woodworker and not a slave to tolerance or flatness or squareness or straightness. If my plane iron is not dead flat, I wouldn't know it as long as my work doesn't show it.

Simon

Very well said, Simon!

BTW I am an Engineer... :-)

A good Engineer will know the precision required for each task. I developed micro chips at 1980s and it required different precision than my tasks in the woodworking shop.

All the best.

[Warren Mickley]

I don't think Sellers' standards are very high. After planing the wood he sands at 240 grit, then applies a sanding coat of finish to raise all the damaged grain and then sands again with 240. With a plane in good order there is no damaged grain and no sanding necessary.

The iron does not need to polished on the back if you don't care how easily the plane works or what kind of surface you obtain.

[Ted Phillips]

Right, engineers should stick to engineering, not woodworking, or how wood as a material actually works. We all know woodworking has been going on much longer than engineering and engineering has contributed little to woodworking, right?

I usually keep my "Woodworking Hat" in the basement. When I get home from work, I take off my Engineer Hat and put it in my briefcase for the night. I put on my Dad/Husband Hat for a little while... but when I get to the basement workshop, on goes the Woodworking Hat. It doesn't fit to within a 0.001" tolerance for my noggin (unlike my Engineer Hat), but it is comfortable and gets the work done... :cool:

TedP

[Andrew Pitonyak]

Here's a quote from Paul Sellers' blog:

Firstly, and I have already said this elsewhere, plane irons need not be dead flat at all.
Secondly, they need not be replaced with any other make of iron and certainly not thicker ones.
Thirdly, if they are bellied they need not be abraded to flatness.
Fourthly, if they are hollow they are ready to go and need minimal restorative work beyond minor abrading and polishing out along the back of the cutting edge.
There, I have just saved you an hour or two’s work.



Could someone explain his point here? If the back of the blade isn't flat, how can it be polished completely across its bottom edge?

If you use the "ruler" trick. You want two edges to meet. You are not, however, registering the back of a blade against your work like you might do with a chisel.

I prefer a flat back, but, I have one plane blade that after lots of work, one corner is still there. So, I did the ruler trick with it and moved on with my life. Great plane, crappy finish on the blade.

[Simon MacGowen]

I don't think Sellers' standards are very high.

That may or may not be true. But what is true is that 95% (if not more) of modern woodworkers I have come across do not have standards higher than his.

Unless elitism is the issue, Sellers' standards are good and high enough, not to mention that his work is in the White House's collection. For a fact, I know Sam Maloof's work is also among it.

Simon

[Alex Liebert]

I think I just find Paul's language hard to interpret, especially in written form.

If he's saying the blade doesn't need to be straight along its length, or if he's saying that only the very tip of the back where it meets the bevel needs to be flat, that makes perfect sense.

It sounded like he was saying that a cup in the back of the blade need not be flattened at the tip, and if that's the case I don't see how that could be. He doesn't advocate the ruler trick, so if he's polishing the edge of the back of the blade but it has a cup in it, surely only the corners of the edge would be getting polished at all.

[Alex Liebert]

I don't think Sellers' standards are very high. After planing the wood he sands at 240 grit, then applies a sanding coat of finish to raise all the damaged grain and then sands again with 240. With a plane in good order there is no damaged grain and no sanding necessary.

The iron does not need to polished on the back if you don't care how easily the plane works or what kind of surface you obtain.

Interesting, and I think it speaks to what I'm getting at.

It seems Paul often hints at the notion that, the focus on precision flatness in tools is a fairly modern thing and not as critical as the web might make one think. I'm playing with a few planes I picked up very inexpensively at a flea market recently. I'm looking at the cutting edge of the blade on one and the back is quite rough, and the bevel is all over the place. It's also almost worn down to the slot, so if nothing else, this tool was used extensively. Was this tool used to produce fine work with an approach to maintenance that's less finicky than today's but still very effective? Did it only ever produce results that as you suggest were not to a high standard?

Bit of a tangent, not trying to stir the pot or get specific restoration tips here- just an example and I'm still curious about where the line is between the precision tuning and fettling in articles and videos, and just how much of that, if any, was ever being done 50 or 100 or more years ago (when beautiful furniture was clearly being made by hand, one way or another.)

(If it matters, my education is in fine art and my professional background is software engineering...puts me a bit at odds when evaluating anything like this)

[Andrew Seemann]

I don't think Sellers' standards are very high. After planing the wood he sands at 240 grit, then applies a sanding coat of finish to raise all the damaged grain and then sands again with 240. With a plane in good order there is no damaged grain and no sanding necessary.

The iron does not need to polished on the back if you don't care how easily the plane works or what kind of surface you obtain.

I think the main thing is whether his standards are high enough for what he is trying to accomplish. You can always have higher standards, but you get to a point (sometimes quite quickly) where higher standards don't make the work better, they just make it more expensive. That whole law of diminishing returns.

[Patrick Chase]

If you use the "ruler" trick. You want two edges to meet. You are not, however, registering the back of a blade against your work like you might do with a chisel.

True, but to get the most out of a BD plane you *do* need to register a cap iron against the black of the blade such that it doesn't create a fiber trap, and IMO that creates tighter requirements for transverse flatness than does a chisel.

[Andrew Seemann]

Interesting, and I think it speaks to what I'm getting at.

It seems Paul often hints at the notion that, the focus on precision flatness in tools is a fairly modern thing and not as critical as the web might make one think. I'm playing with a few planes I picked up very inexpensively at a flea market recently. I'm looking at the cutting edge of the blade on one and the back is quite rough, and the bevel is all over the place. It's also almost worn down to the slot, so if nothing else, this tool was used extensively. Was this tool used to produce fine work with an approach to maintenance that's less finicky than today's but still very effective? Did it only ever produce results that as you suggest were not to a high standard?

Bit of a tangent, not trying to stir the pot or get specific restoration tips here- just an example and I'm still curious about where the line is between the precision tuning and fettling in articles and videos, and just how much of that, if any, was ever being done 50 or 100 or more years ago (when beautiful furniture was clearly being made by hand, one way or another.)

(If it matters, my education is in fine art and my professional background is software engineering...puts me a bit at odds when evaluating anything like this)

If you take a close look at a lot of examples of "old world craftsmanship", you tend to see a lot of examples of things that are not perfectly flat, square, even, etc. For example, I am into historical harpsichords, not a common interest I realize, and when you look closely at revered examples from history, you see some surfaces looking like they are straight from the hatchet (because they are), uneven thicknesses, tear out, joints in keyplates, knots smack in the middle of the bridge, and the like. However, the overall visual effect of the instrument appearance is stunning and the sound is beautiful. But a current day buyer of an instrument made like that would send it back because it was "poor quality" Even though those "defects" had no bearing on the original instrument or its capabilities.

For whatever reason, in modern woodworking, people doing hand tool work seem to want to emulate the (unnecessary) precision of machine work, and people doing machine work want to imitate the (unnecessary) quirks of handwork. To paraphrase Ringo, "It's crazy"

To answer your question directly, I highly doubt people of yesteryear who made their living with their tools fiddled and fettled them as much as hobbyists of today do. Some probably did, but most, not likely. The tools that I inherited from relatives that were cabinet makers and carpenters 50 -100 years ago certainly didn't have that level of "perfection" They just tuned them up as well as they needed to do the job and that was it.

[Jim Koepke]

I'm looking at the cutting edge of the blade on one and the back is quite rough, and the bevel is all over the place. It's also almost worn down to the slot, so if nothing else, this tool was used extensively.

There are a lot of folks who believe a grinder is a sharpener and is all that is needed to sharpen a plane blade, a chisel or knife.

Many a plane blade has come my way with a lot of grinding, but not a lot of work.

jtk

[James Pallas]

I'm not an engineer but I understand a little of it. Let's see the sole of the plane is ground by machine to x tolerance, the frog is than ground by machine to x tolerance, the face of the frog is ground (on decent tools) to x tolerance, the iron is ground by machine on both sides to x tolerance, the cap iron is ground by machine to x tolerance, theses assemblies are clamped to the frog with some force. Then someone comes along with some sandpaper glued to some kind of possibly flat surface and remachines the iron. That's usually done on only one side. It appears to me that the weak link is the last "machinist". Sharpen the back of your iron and the bevel of your iron, check to see if your work has messed with the cap iron to iron fit and go to work on wood it is much more tolerant then your machine work.:)
Jim

[Simon MacGowen]

For whatever reason, in modern woodworking, people doing hand tool work seem to want to emulate the (unnecessary) precision of machine work, and people doing machine work want to imitate the (unnecessary) quirks of handwork. To paraphrase Ringo, "It's crazy

Good observation. A lack of confidence on the maker.

Simon

[Brian Holcombe]

The area behind the edge on the back of the blade does need to be quite accurate and it must match to the cap iron. If this is not done, then thin shavings will catch between the two and cause issue.

That does not mean that 2" behind the blade needs to be flat, but it tends to happen over time and many sharpenings. This is the back of my try plane iron:

https://brianholcombewoodworker.com/wp-content/uploads/2018/05/IMG_7210.jpg

Flat is repeatable, out of flat is very hard to repeat.

[Warren Mickley]

If you take a close look at a lot of examples of "old world craftsmanship", you tend to see a lot of examples of things that are not perfectly flat, square, even, etc. For example, I am into historical harpsichords, not a common interest I realize, and when you look closely at revered examples from history, you see some surfaces looking like they are straight from the hatchet (because they are), uneven thicknesses, tear out, joints in keyplates, knots smack in the middle of the bridge, and the like. However, the overall visual effect of the instrument appearance is stunning and the sound is beautiful. But a current day buyer of an instrument made like that would send it back because it was "poor quality" Even though those "defects" had no bearing on the original instrument or its capabilities.

For whatever reason, in modern woodworking, people doing hand tool work seem to want to emulate the (unnecessary) precision of machine work, and people doing machine work want to imitate the (unnecessary) quirks of handwork. To paraphrase Ringo, "It's crazy"

To answer your question directly, I highly doubt people of yesteryear who made their living with their tools fiddled and fettled them as much as hobbyists of today do. Some probably did, but most, not likely. The tools that I inherited from relatives that were cabinet makers and carpenters 50 -100 years ago certainly didn't have that level of "perfection" They just tuned them up as well as they needed to do the job and that was it.

Craftsmanship 50-100 years ago? It was poor. Even for a beginner it was hard to find someone who knew enough about hand tools to be helpful at all.
Some consulted old men in their 80s, but much more helpful was looking at 18th century furniture, reading old texts from 1830 and before, and experimenting. We have raised the bar considerably in the last 50 years. One cannot do work that that is clean fast and efficient with tools that are not in fine shape. As Brian mentioned, the easiest, most efficient way is to have the back flat. Even the ruler trick takes a lot more of the craftsman's time in the long run.

Did you ever play on a harpsichord made 50 years ago? Again, poor. Harpsichord making improved greatly in the 70s and 80s because makers looked at old instruments from 300 years earlier when when craftsmanship and standards were much higher.

[Todd Stock]

Sellers, Schwarz, and a few other 'celebrity' woodworkers each have thousands of avid fans drinking deeply from the fountain of their peculiar brands of craft wisdom, while at best, a few of us here have a couple dozen acolytes with lemon-lime Kool-Aid stains on their aprons.

I'll take the later situation, as there is far less pressure to make all-too-frequent, sweeping, seemingly contradictory statements to push a blog, book sales, class enrollment, or other line of business. There are also far more cubbyholes available for those of us striving to remain in the micro-fan base category as a woodworking guru, versus just the few categories available to those seeking broad name recognition (e.g., 'Professional Contrarian', 'Ernest Educator', and 'Former Magazine Editor Who Is a Professional Contrarian Turned Starving Ernest Educator'). A quick pass through recent posts shows several currently open niches here, including 'Apprentice Sharpening Wonk Willing to Bury Fans in Abrasives and Alloys Esoterica', 'Side-kick to Cranky Old Dude #8', and 'Assistant to That PITA You'd Most Like to See Forget His Screen-Saver Password.'

[steven c newman]

The area where a chipbreaker sits does need to be flat, to make a gap-free match to the chipbreaker.....but, not the entire back on the iron. Think about this....on a bevel down plane, the area behind the bevel should also be flat.....so it will sit flat on the frog, and not rock. Have seen a few come through the shop, where there was a "hollow" behind the bevel....and packed full of dust and shavings between the iron and the frog...yet, nobody seems worried about this side of the iron? Why go to the trouble to flatten the face of a frog, and not the bevel side of the iron that will rest on that "perfectly flat" frog?

Hmmmmm? Anyone?

[John C Cox]

Here's a quote from Paul Sellers' blog:

Firstly, and I have already said this elsewhere, plane irons need not be dead flat at all.
Secondly, they need not be replaced with any other make of iron and certainly not thicker ones.
Thirdly, if they are bellied they need not be abraded to flatness.
Fourthly, if they are hollow they are ready to go and need minimal restorative work beyond minor abrading and polishing out along the back of the cutting edge.
There, I have just saved you an hour or two’s work.



Could someone explain his point here? If the back of the blade isn't flat, how can it be polished completely across its bottom edge?

What I see here is the admonition of "Quit fiddling with your tools and go work some wood"... I mean the comment "There, I saved you a couple hours..." means - quit obsessing about your plane iron and get to work...

And it's probably the thing that The Crusty Old Master often told the Young idealistic Apprentice (or the over-eager hobby amateur) over and over... Get them sharp and get back to work.... Probably something that Todd and Warren had to say over and over... "It's fine, quit fooling with your tools.... Come on back to the work".

Once you are working wood with your tools - you will quickly see what makes a big difference vs what doesn't....

[Andrew Gibson]

A few years back I was doing a demo for a local woodworking club on hand tool work. One of the members brought in a sweatheart era #6 and asked me if I thought it was worth tuning up. I had my $20 Fulton #6 ebay score with me with original iron, and I said lets see. I swapped my sharp iron in, set the depth, and started planing with the same results I would expect from my own tool. I said clean the tool up, sharpen the iron and the tool should continue to work just fine. As long as the plane is not damages or missing parts, most will function well as long as the iron is sharpened and set properly. Planes are simple tools, don't over think them. I believe in having a flat back because it makes sharpening more consistent. I like the aftermarket plane irons for LV,LN, and Hock because I feel they are better quality steel and mean I spend less time sharpening.

PS. that Fulton #6 is the only bench plane I use that still has it's original iron and cap iron. I never found a need to replace it.

[Osvaldo Cristo]

Here's a quote from Paul Sellers' blog:

Firstly, and I have already said this elsewhere, plane irons need not be dead flat at all.
Secondly, they need not be replaced with any other make of iron and certainly not thicker ones.
Thirdly, if they are bellied they need not be abraded to flatness.
Fourthly, if they are hollow they are ready to go and need minimal restorative work beyond minor abrading and polishing out along the back of the cutting edge.
There, I have just saved you an hour or two’s work.



Could someone explain his point here? If the back of the blade isn't flat, how can it be polished completely across its bottom edge?

The explanation looks me simple: good enough for the purpose he is assuming.

I agree him if your target is to make useful stuff from wood, if your aim is the final object. On the other hand, there is people, mainly hobbyist, interested on the total experience, where the final product is just one more thing from his/her experience and the process counts a lot, also. The experience to use premium tools finely adjusted is odd for several people.

All the best,

[Patrick Chase]

The area where a chipbreaker sits does need to be flat, to make a gap-free match to the chipbreaker.....but, not the entire back on the iron. Think about this....on a bevel down plane, the area behind the bevel should also be flat.....so it will sit flat on the frog, and not rock. Have seen a few come through the shop, where there was a "hollow" behind the bevel....and packed full of dust and shavings between the iron and the frog...yet, nobody seems worried about this side of the iron? Why go to the trouble to flatten the face of a frog, and not the bevel side of the iron that will rest on that "perfectly flat" frog?

Hmmmmm? Anyone?

Flatness is a good thing, but like most good things you can waste time by doing too much of it.

The area where the cap iron mates needs to be flat in the transverse (side-to-side) axis. For most people the easiest way to achieve that is just to make sure that the very tip of the back of the iron is flat. I typically flatten more than that because I find it more convenient to register a longer "patch" on my stones, but doing so has no real impact on the performance of the plane.

I'm also of the opinion that perfect iron<->frog bedding is less important than a lot of people think. Rob Lee has posted on this forum and explicitly confirmed that Veritas designs their planes such that the frog supports the iron at the leading edge of the frog, and on the slight raised boss at the adjuster pivot. The iron is unsupported everywhere else (and this is easily confirmed by probing one of their planes with a feeler gauge). Many other makers do the same. One way to think of it is that the lever cap provides a finite amount of downforce. Concentrating the downforce as close to the edge as possible is such an obvious engineering optimization that it qualified as simple common sense, and that's exactly what designs like Veritas' do. For that reason I think that designs like the Millers Falls 3-point lever cap are actually counterproductive.

[steven c newman]

And yet..I have never had a bit of chatter, from any of the Millers Falls planes I use. Have seen a few irons come through the shop...set them on the frog, and watch them rock..side to side....YMMV