When to replace a plane blade

[Jacob]

...

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.

We were barred from using the grinder in the two places where I had any formal training. And you wouldn't take one on site. Yes the stone takes the wear but they still last for life!
PS re "hollow grind" is this why people get chipped blades? There isn't much room for a hollow grind on a thin blade, without resulting in a weak edge.

 

[D_W]

they're tapered the opposite direction (about 3/8th thick at the top, probably a 16th less at the business end). There are gadgets to hold them to grind them (both the flat side and the bevel side). They're a waste of time, though I have one of them for flattening (more or less a metal bar with a loop and a wedge to hold the tapered iron it.

At any rate, You have to hone and use japanese planes to follow why this isn't the same as western blades or spokeshave blades.

 

[D_W]

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.

There's a second part to the grinder (though it's still quicker), and that's accuracy. The grinder leaves the edge on, the edge remains more accurate. It may be possible to get the same accuracy by hand, but not nearly as quickly.

 

[Jacob]

There's a second part to the grinder (though it's still quicker), and that's accuracy. The grinder leaves the edge on, the edge remains more accurate. It may be possible to get the same accuracy by hand, but not nearly as quickly.

No it's really quick - you just hone at 30º as near as you can judge. Hardly needs thinking about at all.
It's good practice to try to manage without a grindstone for sharpening. Just for metal work such as re shaping or repairing a blade.

 

[Trafalgar]

We were barred from using the grinder in the two places where I had any formal training. And you wouldn't take one on site. Yes the stone takes the wear but they still last for life!

Yours is a viable method. So is grinding on a wheel. Once somebody understands what the grinder is supposed to do, a 30 second explanation at most, it's clear sailing. Either method works. It just depends on what tool you'd rather see do the heavy lifting -- a grinding wheel, or honing stones. Wheels were invented for a reason - they aren't some outlier anachronism. Somebody 'got it.' What else can one say?

 

[D_W]

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

burning edges isn't much of a problem on any grinder, but it can be done easily with the wrong wheel or a heavy hand or both. It's fairly difficult to burn an edge on an 8" full speed grinder with a 24 grit tool room wheel. I literally used that combination about a month ago to set up a group of used japanese chisels to dump on ebay.

Then a couple of weeks later browned a chisel on my sandpaper lap, just to see if it could be done.

Tormek has sold a lot of really slow sharpening machines based on the notion that dry grinding will result in heat or edge problems. It's sort of an odd thing that we'll spend time learning to master some skills and write off others without really trying.

 

[Jacob]

...

Then a couple of weeks later browned a chisel on my sandpaper lap, just to see if it could be done....

Of course it can be done, if dry. Wet n Dry paper works much better and faster, wet. It's designed and intended for wet "grinding".

 

[D_W]

No it's really quick - you just hone at 30º as near as you can judge. Hardly needs thinking about at all.
It's good practice to try to manage without a grindstone for sharpening. Just for metal work such as re shaping or repairing a blade.

Jacob -I've seen more of this and more different ways than you have. I have no problem sharpening by hand, but you're in the weeds for two reasons:
* I'd have a stanley iron ground on a crystolon stone before you could tighten the nut on your jig
* the japanese plane is different. I intentionally managed grinding them by hand because it's pretty, but it goes way beyond what you're doing. The grind has to be about 25 degrees on a slab that's over 1/4th thick. It's not "really quick". You're aiming for a bias around 10 degrees of clearance at the tip after the last step.

I use a grinder most of the time on chisels and irons for two reasons - speed and accuracy. I don't know if the former really amounts to much, but in combination with the latter, it amounts to a lot.

 

[Jacob]

Jacob -I've seen more of this and more different ways than you have. I have no problem sharpening by hand, but you're in the weeds for two reasons:
* I'd have a stanley iron ground on a crystolon stone before you could tighten the nut on your jig
* the japanese plane is different. I intentionally managed grinding them by hand because it's pretty, but it goes way beyond what you're doing. The grind has to be about 25 degrees on a slab that's over 1/4th thick. It's not "really quick". You're aiming for a bias around 10 degrees of clearance at the tip after the last step.

I use a grinder most of the time on chisels and irons for two reasons - speed and accuracy. I don't know if the former really amounts to much, but in combination with the latter, it amounts to a lot.

OK, do it your way!

 

[D_W]

Of course it can be done, if dry. Wet n Dry paper works much better and faster, wet. It's designed and intended for "grinding".

This is again incorrect. silicon carbide paper is made for alloy steels. It's not a great choice for grinding because it's intended to break down at speed on belts, but under pressure it crushes quickly. white alumina paper is faster at grinding and maintains its coarseness (and speed) better.

Silicon carbide will work better only if something nasty is in the steel (like a lot of vanadium or a lot of chromium). I've tried them all. I'm sure you're older than me, but you have spent less time hand grinding and finishing metal than I have. And I'm *really* lazy. When something takes more effort, I notice it.

 

[D_W]

OK do it your way!

I've done it your way. I'd go so far to say as I've functionally mastered it. I have no idea why I'd do it that way if it doesn't work better. I get that you're trying to be helpful here but the real point was method specific to japanese planes (there's no room for rounding) and the large size of the bevel that's also flat making sharpening a pain in the ding if there's any nicking (really, it's a nuisance on those planes in general unless you give in and hollow grind).

If you haven't sharpened a japanese plane in the cycle of work, you're not going to follow why comparing a stanley iron doesn't make sense.

 

[Jacob]

This is again incorrect. silicon carbide paper is made for alloy steels. It's not a great choice for grinding.....

I guess you haven't tried it.
Has to be wet - I use white spirit. The cheapest paper backed is best as it lies very flat on a wettened impervious surface, without need to stick it down - I use my planer bed. It's brilliant for flattening plane soles too.

 

[D_W]

I don't know why you always go down this road. I tried 60, 90, 120 grit paper, both glued down and wet to shorter glass, to 18x12 granite and to my long lap.

I have an oilbath stone setup (in that case, it works wonderfully - there's always more stone below the top layer so crushing a thin layer of abrasive and making it
"sharp" but slower isn't a concern).

The way I flatten (planes) and grind (planes or making new chisels) on al-ox is faster that what you're doing if you're using silicon carbide. Loose paper creates other problems, whether it's held down by water, naptha, mineral spirits, whatever. As far as grinding bevels, the problems are minimal, but a bevel exacerbates crushing the grit. I've got literally 40 sheets of 60 grit silicon carbide paper I'd just give you if you were near here.

It was worth trying, but it's less good than al-ox PSA roll for slow/high pressure on tool steel. Actually, outside of hard grinding wheels and crystolon stones, I don't know where it's better (ceramic alumina belts on a belt grinder are far better than silicon carbide, but they, too, are poor for hand grinding).

 

[Jacob]

I don't know why you always go down this road.

Because it works, is fast and cheap.

...... Loose paper creates other problems, whether it's held down by water, naptha, mineral spirits, whatever. .......

Not if you know how to do it. In fact it solves problems - it couldn't be easier.
You drop paper-backed wet n dry into a pool of white spirit, splash more on top and away you go.
This is what it looks like when you start. After a minute the paper is wetted down very flat and won't shift. Keep it wet with more white spirit. I suppose water would do just as well but not on my planer bed!
For a bigger plane you just put down another sheet next to it.
The paper is reusable and best kept between boards to keep it flat.
Cloth backed paper won't work it won't stick itself down.

PS this is an "SV" brand plane and is the tattiest plane I've ever handled. It was 99p on Ebay but was quite usable after a bit of work.

 

[D_W]

Jacob, this is almost turning into folly. I make tools. In the last week, I've made ten chisels. I flatten them by hand. If your way was better, I'd do it. It's find for you to recommend things other than I recommend, but people following your advice will be going backwards. It's possible for them to use the setup that I have and flatten a plane like you're showing to within a couple of thousandths in about 5 minutes. It's possible to grind the back of an iron without dubbing, or grind a bevel flat if desirable on the al-ox. The al-ox dulls but the grit remains large dull large grit is faster than crushed small grit.

You're suffering from lack of exposure, and without going bonkers into the tiny details, I've literally tried all of the aluminas narrowing down what really works best. The friable aluminas aren't great for this, even though they're far better on a high speed belt machine. I spend appreciable amounts of time doing this, not once in a while partial flattening of an old plane.

if you look over toward the nelson plane thread, you can see the pitting in the iron. I removed all of it and had an iron flat enough for an india stone in 5 minutes.

I can't stop people from taking your advice (nor is it my place). I can tell you that my method is definitively better ,and the difference between you and me is that I've probably done your method more than you have, but I've done my method dozens of times more. If you were at a bench next to me measured both in time and to a standard, you'd fare poorly.

If you and I tried to do something fitting or making a door on a house, I'd fare poorly. But I'm smart enough not to push there.

 

[Jacob]

Jacob, this is almost turning into folly. I make tools. In the last week, I've made ten chisels. I flatten them by hand. If your way was better, I'd do it. It's find for you to recommend things other than I recommend, but people following your advice will be going backwards. It's possible for them to use the setup that I have and flatten a plane like you're showing to within a couple of thousandths in about 5 minutes. It's possible to grind the back of an iron without dubbing, or grind a bevel flat if desirable on the al-ox. The al-ox dulls but the grit remains large dull large grit is faster than crushed small grit.

You're suffering from lack of exposure, and without going bonkers into the tiny details, I've literally tried all of the aluminas narrowing down what really works best. The friable aluminas aren't great for this, even though they're far better on a high speed belt machine. I spend appreciable amounts of time doing this, not once in a while partial flattening of an old plane.

if you look over toward the nelson plane thread, you can see the pitting in the iron. I removed all of it and had an iron flat enough for an india stone in 5 minutes.

I can't stop people from taking your advice (nor is it my place). I can tell you that my method is definitively better ,and the difference between you and me is that I've probably done your method more than you have, but I've done my method dozens of times more. If you were at a bench next to me measured both in time and to a standard, you'd fare poorly.

If you and I tried to do something fitting or making a door on a house, I'd fare poorly. But I'm smart enough not to push there.

OK I don't make tools but I do use them a lot. I would expect to do things differently if I was making them.
You may not realise it but you don't actually give much useful practical advice to a person who merely wants to use the tools!
PS I had a look at the Nelson plane thread. If I was desperate enough to want to use it wouldn't have bothered with all that flattening of the pitted edge I would have just lifted it a touch and imparted a mini bevel on the face, far enough to fit the cap iron too. AKA the ruler trick but easy without the ruler.
Come to think - thats very much what you did, only a longer mini bevel.

 

[D_W]

You're incorrect, but you probably don't know enough to know that.

When someone has asked about flattening irons, I generally say "PSA roll and a glass shelf replacement from a glass supplier, as cheap as you can find".

All of this detail comes out when people like you assert that you know better.

The nelson plane thread is different - it's about setting up a near 200 year old wooden plane to plane anything. If you're just hacking away at door jambs, that kind of setup won't matter. If you're jointing hardwoods and then getting into nonsense about "now, I'll have to have another plane for difficult wood, one with a high angle" then you're wasting time.

You said yourself that you've done most of your work with power tools except early on. It's hard for you to gauge how much efficiency is gained with 45 minutes of setup work if that's the case. You're not looking to learn, that's fine. I meet a lot of people who know too much to learn anything. They know that "it's a waste of time" to learn to do things better than a certain point.

When I get the question about how something should be done, and I offer the short answer above and it's met with armchair experts who have done a hundredth of what I've done, but they're sure that my advice is poor because Paul Sellers did something else, I get enough of it quickly.

You'll note that I don't offer much advice re: things I don't know very well. I'm just not interested in "this is OK, so let's all do OK and ignore someone who knows more about this".

 

[Sgian Dubh]

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!

Okay David. I'm out because actually participating in never ending sharpening threads become a bore to me, but it seems you're correct and there might be 150 or more posts yet to come.

On the other hand, I sometimes quite enjoy all the circular bickering and point scoring that such threads tend towards before they hit rock bottom, ha, ha. Slainte.

 

[D_W]

On the other hand, I sometimes quite enjoy all the circular bickering and point scoring that such threads tend towards before they hit rock bottom, ha, ha. Slainte.

We have a saying here. "I went to a hockey game, and they did nothing but play hockey the whole time. I want a refund."

 

[Jacob]

........
When someone has asked about flattening irons, I generally say "PSA roll and a glass shelf replacement from a glass supplier, as cheap as you can find".

Yes to the glass shelf, I have several pieces too, but my planer bed is longer. Paper backed wet n dry, used very wet, cuts better than PSA dry and lies flatter. That's what it's for primarily - it brings a precision grinding surface into the home workshop. I first encountered it years ago trying to flatten cylinder head faces on my first motorbike.

All of this detail comes out when people like you assert that you know better.

I think I know faster, cheaper and easier

.....
You said yourself that you've done most of your work with power tools except early on. It's hard for you to gauge how much efficiency is gained with 45 minutes of setup work if that's the case.

I've done masses of hand planing - last big one was some very large window 12' stiles too big to manhandle over a planer and some 4x4" newel posts about 20 pieces in all with the longest about 14'. Both cases two faces by hand and the other two through the thicknesser

You're not looking to learn, that's fine.

Seems to be your problem not mine. It's never too late!

When I get the question about how something should be done, and I offer the short answer above and it's met with armchair experts who have done a hundredth of what I've done,

What have you actually made?

...... sure that my advice is poor because Paul Sellers did something else, I get enough of it quickly.

Paul Sellers just happens to have done a vid most closely resembling trad sharpening - though 2 oil stones more normal than 3 diamond stones he uses.

PS another big advantage of wet n dry is that you can lift your paper and swap it for finer/coarser, at the drop of a hat. n.b. I always use the whole A4 size sheet which means a wider impermeable surface than a "shelf". A glass cupboard door is better. 2 A4 sheets end to end will do the sole on a #8. If its a bit concave you can put them further apart and just grind the ends