When to replace a plane blade

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David, you're way ahead of me on metallurgy for plane irons and chisels. For some reason I've never found a need to get excited about the subject. When it comes to plane irons and chisels I have always simply sharpened and used whatever variety of steel the tool came with. And I've got a bit of a mix of tools, e.g., Stanley, Record, Clifton, Spiers and a couple of pretty useless Norris jobs, and an old wooden plane or two, and my collection of bench and carving chisels is a right old dog's dinner of old examples (forty or fifty years old) to I've no idea back through the 20th and 19th century.

Some seem to perform a bit better than others through things like edge retention, resistance to chipping, lack of folding over, and ability to regrind and sharpen without overheating or taking a long time. They all work and I'm used to all their little quirks regarding those listed performance criteria, and some I've probably forgotten.

The point I'm getting to is that I've nearly always taken an interest in those discussions where metallurgy gets discussed, where frequently you are a major participant. I usually find those sorts of threads interesting enough to follow all the minutiae and sometimes the nit-picking between participants. Yet, somehow none of those discussions seem to ever inspire me to change any of my plane irons or seek out new 'better' chisels. I just keep doing away sharpening and using whatever steel came with my tools. What a boring old stick in the mud I must be, ha ha. Slainte.
What you haven't tried PMT 747 honed at 33.5º? o_O
 
David, you're way ahead of me on metallurgy for plane irons and chisels. For some reason I've never found a need to get excited about the subject. When it comes to plane irons and chisels I have always simply sharpened and used whatever variety of steel the tool came with. And I've got a bit of a mix of tools, e.g., Stanley, Record, Clifton, Spiers and a couple of pretty useless Norris jobs, and an old wooden plane or two, and my collection of bench and carving chisels is a right old dog's dinner of old examples (forty or fifty years old) to I've no idea back through the 20th and 19th century.

Some seem to perform a bit better than others through things like edge retention, resistance to chipping, lack of folding over, and ability to regrind and sharpen without overheating or taking a long time. They all work and I'm used to all their little quirks regarding those listed performance criteria, and some I've probably forgotten.

The point I'm getting to is that I've nearly always taken an interest in those discussions where metallurgy gets discussed, where frequently you are a major participant. I usually find those sorts of threads interesting enough to follow all the minutiae and sometimes the nit-picking between participants. Yet, somehow none of those discussions seem to ever inspire me to change any of my plane irons or seek out new 'better' chisels. I just keep doing away sharpening and using whatever steel came with my tools. What a boring old stick in the mud I must be, ha ha. Slainte.

All of the ones I've outlined here are basically "plain" steel except XHP if I mentioned it. The only real reason to replace any iron is if it's too soft or overhard. Even the latter may be solvable by the average individual by experimenting with the oven.

I'm interested in an iron from a maker's perspective, and to some extent in using them - If I'm a maker, then I"m going to go to the point of finding out what works best (just as a furniture maker may know a whole lot about drawer design. The person who buys the furniture is looking to open the drawer and close it. If you tell them about the next stylish way to make drawers, and theirs holds their socks (bill's words) and opens and closes, they'll say "that's nice"

Kind of like that here. (one exception)

I prefer the plain stuff for irons, though - the modern stuff wins idealized contests and also does better if you're planing brass. hah.

exception - if you dimension by hand, then irons that nick or chip or dull unpredictably are kind of like having the same thing occur in a machine planer, and I know well enough to know that people don't like that.

I haven't seen anyone who dimensions by hand talk much about edge life because any decent iron has edge life proportional to sharpenability.
 
I prefer the plain stuff for irons, though - the modern stuff wins idealized contests and also does better if you're planing brass. hah.

exception - if you dimension by hand, then irons that nick or chip or dull unpredictably are kind of like having the same thing occur in a machine planer, and I know well enough to know that people don't like that.

I haven't seen anyone who dimensions by hand talk much about edge life because any decent iron has edge life proportional to sharpenability.
I'd say your last comment has most relevance to me, i.e., edge life proportional to its ease of sharpening. The truth is I've always found that whatever the makers have chosen for their cutting edge steel in planes and chisels have, for the greatest part, been good enough for me. In my early days I had to do a lot of basic dimensioning of rough sawn wood using hand tools, but that's a relatively rare activity for me now. Machines take out the drudgery of that task, i.e., table saws and bandsaws, plus planers and thicknessers. But yes, it would have been, and surely still is, a thankless task to undertake basic dimensioning with planes that won't hold an edge for a decent period, or an edge that chips or folds too easily, along with being difficult and slow to sharpen after an inconveniently short period of use.

As I mentioned in an earlier post I do find the discussions about the 'best' steels for plane irons and chisels interesting, and maybe saws too, but those discussions have had no practical impact for me as a furniture maker. I think that's down to the factors I've mentioned, i.e., all my plane irons that came with the tool (plus a replacement or two), and chisels seem to work fine for me. I therefore don't really have any motivation to explore tool steel that might, or might not, perform marginally better than what I use now. True, if all my plane irons and chisels are, or were, sad shonky examples that performed terribly perhaps I'd have motivation to find something better, but that's really not the case.

I'm happy to observe with some interest from the sidelines, leaving all that metallurgy stuff to people like you that have a real interest in the subject. Maybe one day something in those discussions will make me go out and get a new iron in some sort of fancy steel for one of my planes, but I suspect that's very unlikely. Slainte.
 
The truth is I've always found that whatever the makers have chosen for their cutting edge steel in planes and chisels have, for the greatest part, been good enough for me.
The same for me. I have never replaced a plane iron in any plane, even cheap planes. However, I have one plane iron that is, even to an amateur like me, noticably better than the norm. This is a Swedish iron that dates back to soon after 1900; it is currently in a wooden plane that may well not be that old. This iron sharpens nicely, cuts very well and I love using it. I can't comment on how well it holds an edge because I don't measure things like that but I haven't noticed any issue there.

From this I conclude that standard irons are good enough for me but I do recognise that better irons are possible. So if I ever had to replace an iron I might consider an "upmarket" option, but I am unlikely to replace an iron unless & until forced to do so.
 
There are certainly measurable differences between the irons, and by feel, you can tell what you're using when you get used to certain things (coincidentally, I've sharpened a lot of razors, and I've never really loved the eskilstuna steels in razors, but they make nice chisels and plane irons).

But are they material? I have paid a lot of attention to toolmaking from the amateur maker's standpoint, but to efficiency and comfort in dimensioning from the dimensioner's standpoint because I wanted to nail down how to make dimensioning enjoyable - I've done it for the majority of what I've made in the last 10 years and plan to do it as long as I'm physically able. Little things make big differences there. There are two that are monstrously more important than premium plane irons, though, or even good ones. All I really care is that an iron doesn't chip or fold. Anything in the performance gap between those two, I don't really care about (prefer not to have irons full of lots of vanadium that become very difficult to grind and sharpen, but none of the "chrome vanadium" tools actually have much vanadium in them - they have little bits and its for hardenability. Specialty lathe turning high end steels, etc, have lots of vanadium in them for people who like to turn dirty stumps, etc).

The two things that are important:
1) learning to use the cap iron. It halves dimensioning time in wood that's anything other than dead perfect
2) learning to sharpen faster

#1 drastically increases how much wood you can take on a stroke for all middle and fine work, and decreases the need for surface quality dependent on sharpness (uniformity becomes more important). Any decent oilstone will plane anything, even the mid grade ones. Anything, really anything, too - figured bubinga, whatever.

#2 is obvious. once clearance is running out, squeezing more distance out of a plane is very undude when it comes to effort. Sharpening has to be accurate, too, but it's hard to be in the cycle of results and not notice when it's not accurate enough.

Optimizing something like plane iron steels, etc, is kind of a waste of time if it ignores either of the two above. Wear and honing/grinding are related, but there are a whole bunch of other conditions if you're going to maximize laziness (having a whole setup that, for example, both allows fast sharpening but automatically keeps ahead of nicking without doing extra work).

I target a minute to sharpen from totally dull, but to get as good of sharpness as I can get.

Though I like to talk about these details and make tools, I'd call replacing irons that work well a waste of time. Going for a certain feel or characteristic as a matter of interest is something else entirely, though. Kind of like buying expensive furniture. It's not something I'd do, but there have been generations of woodworkers who have benefited from it.

(just for fun reference, my softest older irons are freres and dwight/french (which I think was a US maker). You can almost roll a burr on them, and they may not be very good smoothers in hardwoods - ...ok ,they aren't. But they're wonderful in a try plane or a jack plane because they refresh with almost no effort. Learning to get the greatest volume of work done with a soft iron can teach a lot of useful things that carry over to the more typical good irons (like pre-70s stanley irons. Stanley's 1950s and earlier efforts in the US are wonderful in a cycle of real work).

I made and sold a coffin plane last year (just to try a wear design). Someone on another forum gave me a couple of eskilstuna irons that someone had. To my disappointment, the iron that I had chipped easily even though it didn't seem ungodly hard. I put it away and didn't think about it until I listed the plane.

Someone finally bought it on ebay (chipping mentioned and all - everything will sell if you wait long enough) - and I decided being much farther along that I"d offer to temper it back a little and reharden it if necessary - the buyer agreed. I tempered it back for half an hour in a toaster oven and it was sweet as pie to use. That's going back to mentioning the territory between tough enough (soft enough) and strong enough (hard enough). Good irons generally have a pretty big spread between those two.

There's no way I could measure a volume of work now being competent with planes and dimensioning and point to changing irons (other than outright defective) to improve results or time spent, though. Fascination with planing twice as long is an agreement between the dealers and the people with a 7 minute sharpening routine.
 
Fascination with planing twice as long is an agreement between the dealers and the people with a 7 minute sharpening routine.
David, some of what you said in that post kind of went over my head. But I had no trouble understanding the bit about setting the cap iron for dimensioning. before that though, there's getting the cap iron to be a good fit to the flat face of the blade, and a decent profile to direct the shavings up and away. Poor fit equals shavings becoming trapped between the cap iron and the blade - that'll take all the pleasure out of planing. And if the curved outer profile of the cap iron isn't great the shavings can do weird things frequently leading to clogging and time devouring clearing out blockages. Correcting both problems takes a bit of time, but it's time well spent, then it's just a case of working out the right distance for setting the gap between the cutting edge and the leading edge of the cap iron - coarse planing to initial dimensions can become almost enjoyable again. I'm not a big fan of that activity because it's generally far too time consuming in the work I've always been involved in - the machines win on that front.

As to the seven minute sharpening routine (and longer for some people), well, hmm? That's okay if there are no real productivity requirements, but I've never really had that luxury. As I think you know, for the majority of my honing I have a Sharp'n'Go methodology of one stone, a bit of flipping on the palm of my hand and back to work, all rather driven by the need to generally get stuff out of the door asap. Final planing, when required, prior to finishing does generally get me to do the sharpening a bit more thoroughly, I've been known to use two stones, one finer than the other prior to a bit of final stropping, and now sometimes a bit of buffing. Slainte.
 
David, some of what you said in that post kind of went over my head. But I had no trouble understanding the bit about setting the cap iron for dimensioning. before that though, there's getting the cap iron to be a good fit to the flat face of the blade, and a decent profile to direct the shavings up and away. Poor fit equals shavings becoming trapped between the cap iron and the blade - that'll take all the pleasure out of planing. And if the curved outer profile of the cap iron isn't great the shavings can do weird things frequently leading to clogging and time devouring clearing out blockages. Correcting both problems takes a bit of time, but it's time well spent, then it's just a case of working out the right distance for setting the gap between the cutting edge and the leading edge of the cap iron - coarse planing to initial dimensions can become almost enjoyable again. I'm not a big fan of that activity because it's generally far too time consuming in the work I've always been involved in - the machines win on that front.

As to the seven minute sharpening routine (and longer for some people), well, hmm? That's okay if there are no real productivity requirements, but I've never really had that luxury. As I think you know, for the majority of my honing I have a Sharp'n'Go methodology of one stone, a bit of flipping on the palm of my hand and back to work, all rather driven by the need to generally get stuff out of the door asap. Final planing, when required, prior to finishing does generally get me to do the sharpening a bit more thoroughly, I've been known to use two stones, one finer than the other prior to a bit of final stropping, and now sometimes a bit of buffing. Slainte.

I quite like your routine. I'm a fanatic for outcome more than routine, but I like that your process uses a stone that's fast enough to get the job done and you've mentioned that you were coached (and do coach) to work the back first at the beginning and then at the end. If one is focused on outcomes (based on what I see coming through when I offer to fit tools), the cap iron is never prepared quite the way I would (I have a blinding fast process for that now, and just do it), sometimes the bevel comes up short, but the back work on the iron at the tip has come up short in every instance except for one.

The 7 minute comment was quoting someone who had more or less a 7 stone progression on another forum and flatly stated that they found the process quite quick (at 7 minutes!!) and that sharpening any other way would not yield a good result. It wasn't warren, but I like one of warren's lines "don't confuse you can't with can't", paraphrased.

One of my favorite things to suggest to people who are having trouble with freehand is to grind and use one medium stone (like a washita or one grade of ark below the black or trans type) and a leather strop. About 75% report edges better than they've had before (despite concerns that the stone they're using won't be fine enough). They weren't finishing the job prior.

If someone were paying me, I'd use machines to dimension. Counting time and dollars would enter into the equation quickly. Unless I could figure out how to convince people that something was better if it's dimensioned by hand (despite being a fan of hand dimensioning, such an explanation escapes me).

if I weren't a toolmaker, I'd replace irons in tools that needed them with precision ground O1 - never would've needed to look further. Fascination with others and need are two different things (even so, if I tried to sell my chisels to an anonymous type platform like etsy, i couldn't go on and on about the various little bits that make files just a bit sweeter than O1 -10 people would buy "O1" (they'd recognize it) for everyone 1 who would be swayed by other things. )

And the work done with either chisel is the same. Just like sock storage in nice furniture vs. cheap drawers that work.
 
I quite like your routine. I'm a fanatic for outcome more than routine, but I like that your process uses a stone that's fast enough to get the job done and you've mentioned that you were coached (and do coach) to work the back first at the beginning and then at the end.
For most sharpening I use either the fine side of a combination oilstone, or a ceramic stone which I think is meant to be 800 grit. It just depends where I'm working which stone I use. I don't think I was taught to start with working the flat side of a plane iron or chisel first, although during my training the need to keep the flat side of the tool flat was emphasised. I think, if I remember it right, that my routine evolved into spending ten or so seconds working the flat side first. I seem to remember thinking when I started that routine that it was simply a 'good idea' because it needed doing anyway. So, the routine for me is work the flat side a bit, flip over and work the honing angle as long as necessary, then remove the wire edge on the flat side, and finally flip the tool back and forth on the palm of my hand, which I guess is akin to stropping. I did learn that flipping thing from my first teacher, and I've never lost the habit. Anyway, that does it for I guess 100% of my chisel work, and probably 90% of all the planing I do.

The 7 minute comment was quoting someone who had more or less a 7 stone progression on another forum and flatly stated that they found the process quite quick (at 7 minutes!!) and that sharpening any other way would not yield a good result. It wasn't warren, but I like one of warren's lines "don't confuse you can't with can't", paraphrased.
Well, taking up just about 1/8 of an hour to sharpen just one plane iron or chisel does seem excessively slow for routine run-of-the-mill sharpening. Imagine if the poor sod had four plane irons or chisels to sharpen all at the same time. Nearly half an hour poncing around on a five minute task like that in a busy workshop probably wouldn't make you popular with the boss, ha, ha.

Incidentally, I think we've done and dusted this topic in this thread now. Slainte.
 
......

Incidentally, I think we've done and dusted this topic in this thread now. Slainte.
It ain't over til the fat lady sings....
I do that quick bevel and face thing very frequently, and hand strop, sometimes leather strop.
If you are doing a lot of planing it's an excuse to stop and it doesn't really take up any time at all because it makes the planing easier. It's vaguely equivalent to sharpening a pencil.
Once you've sussed how easy freehand sharpening is it's all the attention the plane is going to need, for the life of the blade - many years in fact.
One concession to modern plane fetishism which I've indulged in is several Clifton 2 piece cap irons - you get a lot of sharpenings in before you have to move it.
 
Well, taking up just about 1/8 of an hour to sharpen just one plane iron or chisel does seem excessively slow for routine run-of-the-mill sharpening. Imagine if the poor sod had four plane irons or chisels to sharpen all at the same time. Nearly half an hour poncing around on a five minute task like that in a busy workshop probably wouldn't make you popular with the boss, ha, ha.

Incidentally, I think we've done and dusted this topic in this thread now. Slainte.

Oh, Richard! This is a sharpening/tool topic, it must have 90% of its life left ahead of it. All it takes is someone to bicker and this could go for 150 posts! hah!

Your comment about 1/8th hour reminds me of something that I actually did. Not much has changed in sharpening western tools, but I kept a couple of japanese planes for a while (I still have a bunch, but I kept two in top shape and seasonally adjusted). If nothing ever happens to the edge of a japanese plane, then you can resharpen them entirely by hand, neatly, in an annoying 3-4 minutes.

But, at one point I as using one of my planes and the iron was dull and it took a little longer than the above (figure 6 minutes) I don't know what was wrong with it, but it needed more grinding. I decided to do it the "right way" and ground it a bit harder back and fully refreshed the whole thing plus a little depth. It took about 9 minutes. I planed just a little and the iron chipped again (I was finish smoothing). Now, I have about one minute of planing in place and about 15 minutes of honing and my hands ached from grinding the iron. I ground out the chipping *again*, honed the iron and put the plane away. Now, I'm at about 23 or 24 minutes and one minute of it was planing (and I put the plane away after that).

If sharpening takes that long, sooner or later one will run into silica or dirt or whatever else, and get demoralized.
 
......Now, I have about one minute of planing in place and about 15 minutes of honing and my hands ached from grinding the iron. I ground out the chipping *again*, honed the iron and put the plane away. ......
Grinding freehand on a flat stone is much easier if you make a little handle. Say 10" of 2" x 1/2" with a hole for the bolt. You can put a lot of force into it with both hands. Even heavy woody blades become grindable without power assistance.
Do it Paul Sellers style. Fast and furious leads to slightly rounded bevel but that's OK. Honing the same way can defer the need for grinding indefinitely.
I added a knob to this one. Just a bit of pallet wood, a bolt and a spare door knob.

I tend to ignore the odd chip in the edge - they get honed out eventually and it don't affect planing performance unless final finishing with a plane.

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japanese plane, jacob. Short fat iron, you hold the butt of it in your palm and put finger pressure on the (enormous) bevel. They're referenced flat on the large bevel and anyone with appropriate laziness will at least bias pressure toward the edge. A 38 degree bed means there's no forgiveness for any rounding, but the reality is, the fight for clearance makes for no forgiveness for anything. chipping stops around 33 degrees in hardwoods, and those planes don't give the room to do that (5 clearance will feel like a dull plane at the start, even if it planes a clean surface). Totally different animal, anyway.

I have a gadget like that for flattening irons, though. Nelson Plane Setup

not only keeps fingers from getting stiff, but keeps them from getting blistered by heat.
 
Grinding doesn't shorten a tool unless you need to take out a nick, it only thins by virtue of the hollow it imparts. People who routinely grind and produce a burr at the grinder have a fundamentally flawed misunderstanding of the process. The grinder is not one's enemy.

There, that ought to keep this one going for a while... ;)
 
.... The grinder is not one's enemy.
It is if you only have 6" bench grinder - they end up looking as though nibbled by rats and easily get over heated.
Even a Pro-edge will over heat. I had one briefly but sold it on when I realised I could manage quite well without it- not least because of the 12" disc which came with my lathe
 
It is if you only have 6" bench grinder - they end up looking as though nibbled by rats and easily get over heated.
Even a Pro-edge will over heat. I had one briefly but sold it on when I realised I could manage quite well without it- not least because of the 12" disc which came with my lathe

Not at all. Even a wheel dressed (worn) down to 5" or so will put a hollow on a thin plane iron that doesn't go all the way to the edge - just takes a couple of passes. Grinding takes a light touch. The wheel, and electricity, do all the work. Anybody with white knuckles and knotted forearms at the grinder is working way too hard. You hardly need to press at all. Just offer the tool to the wheel with the minimum amount of pressure needed to maintain control.

Your method works Jacob, it just substitutes the honing stone for the grinder. The stones take the wear that the grinder otherwise would have. This is precisely why grinders were invented in the first place.
 
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japanese plane, jacob. Short fat iron, you hold the butt of it in your palm and put finger pressure on the (enormous) bevel. ....
You need to work on the design of your blade holder then. Basically a saw kerf in the end of your piece of scrap - as seen often, particularly with short spokeshave blades difficult to hold. Doesn't need to be a tight fit or bolted on - the pressure of using it keeps the blade in place.
 
Not at all. Even a wheel dressed (worn) down to 5" or so will put a hollow on a thin plane iron that doesn't go all the way to the edge. Grinding takes a light touch. The wheel, and electricity, do all the work. Anybody with white knuckles at the grinder is working way too hard. You hardly need to press at all. Just offer the tool to the wheel with the minimum amount of pressure to maintain control.
Basically I don't grind thin irons at all (or small chisels), except for remedial work. That's the whole point of thin irons and the Stanley/Bailey design; easier and quicker to sharpen.
 

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