Coarse (and durable) medium for blade sharpening?

[Peter Daniels]

Fall always has me in the shop more.
And that has me sharpening more.

I’ve had a hell of a time sharpening a Veritas plane blade (PMV-11) over the years.
If I ever need to re-establish the primary bevel-it’s a long process full of frustration.
I’ve tried a coarse diamond stone.
A very coarse sharpening stone.
Various sand paper style sheets.

All do ok for a bit. And then seem to dull or become smooth making the process extra slow.

The diamond stone doesn’t seem as coarse as it once was.
The stones eventually develop a cup.
And the paper works for a short bit but also becomes less abrasive.

Do you have any suggestions for a durable material I can use for those initial steps when I’m needing to remove material and not just touch up an already perfect edge?

Thanks.
PD

[Tony Wilkins]

Have you thought about a bench grinder?

[Rob Luter]

I use a slow speed bench grinder for big jobs, but as far as stones go, I use a Trend 300/1000 Diamond Bench Stone. It makes short work of tough steel.

[Jim Koepke]

There are only a couple of PMv-11 blades in my shop. I may have put them up against my water stones, can't recall. For sure they have been honed on a Washita, Hard Arkansas, a Black Arkansas or a Translucent Arkansas.

Mostly these days my water stones only get used on A2 or occasionally when trying something different.

jtk

[Richard Hutchings]

Don't wear your self and your stones out like tha5. It's perfectly OK to use a high speed grinder if that's all you have. It's what I use. Just make sure to dunk it in water every so often. The concave grind takes all the work out of sharpening on the stones later on.

[George Yetka]

Ive not had to re-establish bevels on my pmv11 stuff. I did it once and have been luck enough for the past 8 years to just start at 1000/3000 and sharpen to 10k. I have a DMT Diaflat that I use to keep stones flat and that would be where I would go to reestablish if I had to. I may even pick up a dedicated 300 stone if it were needed, Though I dont use hand tools every day.

[Tom M King]

If you absolutely don't want to use a bench grinder:

https://sawmillcreek.org/showthread.php?302722-24-46-and-80-grit-sharpening-stones

[Rafael Herrera]

Nowadays I tend to use the bench grinder to establish the primary bevel, shallower than the ultimate cutting bevel so that I only sharpen a narrow strip at the tip. I'm not that obsessive about this primary bevel, it does not look pretty or flat. Some people feel uncomfortable with this look and want a uniform and a specific bevel angle. For this, a simple method is to use PSA (pressure sensitive adhesive) 80 grit sandpaper, a flat substrate, blue tape, and a honing guide. Cover the substrate with the blue tape, place the sandpaper on top of it and then go to town on the iron. The reason for the blue tape is that it makes it very easy to replace the sandpaper. After a few passes the iron can get very hot, so you may want to wear gloves and have some water available to cool it.

What I wrote above is not a sharpening method, it's meant for quickly removing the metal to form the bevel. Something that is done infrequently.

That's what it sounds like what you're after, since you're asking about coarse media. However, you may be sharpening using a single bevel, you didn't say. That makes the sharpening process tedious and slow, since you're working on the whole bevel every time, regardless of the media.

If using the shallow primary bevel style, I would use a medium diamond stone followed by a fine stone.

Rafael

[Reed Gray]

I use a platform on a slow speed grinder with CBN wheels to set my primary bevel. I have not had any problems, and that includes some antique blades that were very rounded over. Main thing is to pay attention to heating the blade. Another alternative would be the Tormek and the diamond stones. If the primary bevel is really bad, you can use 80 or so grit of the abrasive belts that are made for metal. Again, care must be taken to avoid overheating the metal so that it loses the temper. Once I have my primary bevel established, I take it to diamond stones, 120 grit and up.

robo hippy

[Jimmy Harris]

Sharpening stones are for sharpening. Bench grinders are for grinding bevels. You can grind a bevel with a sharpening stone, I've definitely done it before, but it takes forever and wears out your stone. Oustside of a bench grinder, maybe your best bet is something like a belt sander or file? Cutting steel is hard and it's gonna eat up whatever you use to sharpen it. So don't use something expensive. Bench grinders are pretty cheap, and I'd rather buy a cheap grinder for occasional use than waste a good file, good stone, or lots of sanding belts.

[Prashun Patel]

A bench grinder with CBN wheel (180 grit or 80 grit are fine for this purpose) are really nice to have. The CBN is expensive but runs truer and lasts longer than a typical friable wheel.

A bench grinder will be much faster than stones for primary bevel setting. It makes a hollow grind, which can assist with freehand sharpening of the secondary bevel on the stones.

[Richard Coers]

Don't wear your self and your stones out like tha5. It's perfectly OK to use a high speed grinder if that's all you have. It's what I use. Just make sure to dunk it in water every so often. The concave grind takes all the work out of sharpening on the stones later on.
I thought dunking in water was verboten? If the hard steel is too hot you can induce some micro cracking.

[Tony Wilkins]

I thought dunking in water was verboten? If the hard steel is too hot you can induce some micro cracking.

It won’t hurt if you do it often and before you get the steel too hot.

[Richard Hutchings]

What he said

[John C Cox]

I love my worksharp for exactly this sort of duty. 80-grit Diablo PSA discs (available via BORG) make quick work of chips and dings. Once you are up to P400 or so, move back to the stones.

There are several very fast coarse stones out there. Unfortunately, they tend to be quite friable and require regular flattening. Regular old Norton India stones work nicely once you flatten/refresh them, but they're still a lot slower than power.... Gice me power for grinding any day. I save my stones for final honing.

[Peter Daniels]

So you're saying that the arc of the round wheel will cause a slight concave grind to the blade? So the leading edge and the rear edge of the primary bevel will later touch my sharpening stones after the wheel, which will speed up the normal sharpening process.

Ive read about concave sharpening and have wondered what that was about.
Thank you.

[Peter Daniels]

THis is all really good info.

If i understand it all correctly- first choice, bench grinder.
I have one, but need an accurate sturdy bench rest to help keep the angle as I'd like it.
And if I refuse to use a grinder, get a rubbing stone that was the same one the Pyramids were ground down with.

And if those things are also not the answers I want, I need to understand that this project will likely quickly wear everything else down fast. Diamonds. Stones. Paper. And the rest.

Take care all.
Thanks for such a generous dollop of knowledge on the overbeat topic of sharpening.

[Warren Mickley]

I think a more efficient way is to avoid grinders and stainless steels like Pm v11 and sharpen entirely with bench stones. In order to make this efficient, you have to learn to even out the wear on the stone, making sure the edges get as much wear as the middle of the stone. You get a longer life out of the stone and avoid flattening time. This is the traditional way of using a stone whether in Japan or Pennsylvania.

[Richard Hutchings]

That's true only after the bevel has been established. Once that's done the grinder isn't needed again, though it would speed things up once the cocavity is gone after multiple sharpening.

[Rafael Herrera]

When re-profiling an old vintage chisel or iron, sometimes I use a slow speed grinder to remove some of heel off the bevel and then used a coarse stone, the best stone for this is a coarse crystolon or carborundum bench stone. These are very friable stones, but as pointed out by Warren, by evening out the wear the stone can be kept reasonably flat. On other occasions, when the bevel is not too bad, the first stone is the crystolon.

There's nothing wrong with using some kind of device to get tool sharp, but I don't know if it's worth spending $1000 or more on a Tormek and its attachments when simpler and better methods are available. Specially in my case, where it's just me in my small workshop.

Rafael

[Peter Daniels]

…I don't know if it's worth spending $1000 or more on a Tormek…

Rafael
In so many corners of my life I see examples of things that are more and more expensive, while the benefits get smaller and smaller.
On bicycles you’ll see a set of wheels that are outlandishly expensive. Fiber spokes and carbon rims, amazing things really. Made of unicorn bones and alien tech, but really the difference between them and many other wheel sets is slim.
In sharpening I see basic set ups. Hand guiding. And those people make some gorgeous items.
And I see very complex set ups in shops that are either amazing or YouTube click bait. Sometimes I think people are putting more effort into their influencer media than their woodworking- which is why I came to you all.
Lots of ways to solve this puzzle. And lots of good things to make with sharp tools.

[Tom M King]

I bought a Wen wet grinder to hold me over until Tormek comes out with one that has a reverse. It has surprised me, and will grind an edge just fine. Of course, like the Tormek, 150 rpm is a slow process, but at least you can't harm the temper in an edge. On chisels I like for the water to roll over the edge, and on turning tools I like to see what is being done to a small edge, but don't want to take time to spin the grinder around an swap things around. The Wen has a reverse. It's a lot cruder than a Tormek, but it does good enough.

My CBN wheel has gotten worn to the place where it put too much heat in an edge. Even though it's slowed down a lot, it's still faster than most methods. I use it to get the heel out of the way without getting real close to the edge, then finish the regrind on the Wen. I didn't really want to replace the CBN wheel since I don't use it that much anyway, and it serves just fine like this.

Those coarse stones I posted about in the thread I linked to went in my tile work kit.

[Mel Fulks]

I like the white wheels , they grind fast and don’t heat up as quickly as the grey Caborundum wheels . The coarse good brands of grey
wheels are OK , “once you can grind and dip….and be quick” The cheap grey wheels burn fast , but never wear out , but the good
news is if you have a cheap grey wheel you can make jewelry for your wife our of it ‘cuz it’s almost as hard as a diamond …and cheaper !’

[Jim Koepke]

On bicycles you’ll see a set of wheels that are outlandishly expensive. Fiber spokes and carbon rims, amazing things really. Made of unicorn bones and alien tech, but really the difference between them and many other wheel sets is slim.

I used to be very much into bicycling many years ago. The rotational momentum of the wheels could make a lot of difference for those who desired going fast.

It may have been my good fortune to not have such equipment during my younger years. Some of my wrecks could have been much worse.

At the finish line the slim margin of an inch or two makes a lot of difference.

jtk

[Derek Cohen]

So you're saying that the arc of the round wheel will cause a slight concave grind to the blade? So the leading edge and the rear edge of the primary bevel will later touch my sharpening stones after the wheel, which will speed up the normal sharpening process.

Ive read about concave sharpening and have wondered what that was about.
Thank you.

Peter, efficiency and speed in sharpening is the result of finding a method which reduces the effort as best we can.

Further, everything is a compromise: which steel is used in the blade, the type and grit of the sharpening media, and experience. The latter will trump all else.

Most importantly, with hard and abrasion-resistant steel, such as PM-V11 (which I can argue that I have used for longer than any other amateur woodworker, since I have done so since before Veritas/Lee Valley put it into production), the key element is to minimise the area to sharpen. In fact, uf you reduce the area (i.e. thickness of the blade) enough, it is possible to use even cheap or higher grit stones.

The key elemant to reducing the thickness of PM-V11 blades, the plane blades being 1/8" - 3/16", is hollow grinding. And the closer one gets to the edge if the blade, the less steel there will be.

Grinding is the key to easy, quick sharpening. I began using CBN wheels on a half-speed 8" bench grinder many years ago, and I have not had a reason to change this practice. 180 grit is a good alrounder. I dislike sharpening, but I like sharp blades. My system works for me. It may work for you, but keep in mind that I am also pretty exoerienced at this, and take some factors for granted. You need to suck it and see.

My set up: http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp.html

The alternative to hollow grinding is a secondary bevel on a flat grind. I prefer not to do this as sharpening flat on the hollow creates a coplanar bevel, which is easier to use when you ride the evel face. Hollow grinding does not use up more steel as the hollow is taken from inside the bevel face.

Regards from Perth

Derek

[Peter Daniels]

Derek!
Im barely on the SawMillCreek threads and somehow you have been there to answer other questions ive had.
And as before-your answer is a good one, chok-a-blok w/ good info.
But holy smokes- your sharpening nirvana will never be a thing that I'll have. But I can echo the edges of it maybe.... over time anyway.

I'm in the woodshop as time allows and will continue to chew on this and find a solution that works.
And, if history repeats, bits of all of your answers will make sense while I stumble along into my learning curve.

-PD

[Mike Henderson]

I use the WorkSharp with a diamond plate to establish a 25 degree primary bevel and then go to my Shapton stones to put on a secondary bevel at whatever angle I want. It's quick and easy.

Mike

[Reed Gray]

I did get some PM V11 blades as kits to make some hand planes, but haven't worked with them yet. I did make a marking knife with some M42 HSS that I got from D Way. When sharpening it, as near as I can tell, I get about the same edge as I get on A2. Only real difference I can tell is that when stropping, the burr tends to break off rather than bend back and forth several times before it breaks off. I use V10 gouges and M42 HSS gouges on my wood lathes. I never take those edges beyond 600 grit. I can tell no difference in edge durability or overall sharpness. I did make one chisel out of a piece of M42, and pretty much the same thing as with the A2 my other chisels are made from, it takes a very keen edge, and holds the edge for a long time. Longer than A2? I don't know, yet....

robo hippy

[Rafael Herrera]

Here's what I normally do to refurbish an old iron. This is a 1920s Stanley iron from a jack plane.

Mark the area to be removed, grind that off with the bench grinder, and grind a new bevel. 10 minutes.

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Finish the bevel on a crystolon stone. 7 minutes.

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Start sharpening with a medium India. 7 minutes.

509267

(continued)

[Rafael Herrera]

Finish the blade on the Washita, including the face of the iron. 5 minutes.

509272

Strop.

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These are irons that can achieve a very fine edge, they are good ones. It easily shaved my arm hair.

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Despite the use of a bench grinder, this is not a hollow ground edge. Special equipment, guides and such, are need to get the uniform hollow for that method. Free hand grinding is less accurate.

Would this method work for a steel like PM-V11? I don't know. The ones I have need only sharpening, not to be taken to the grinder. One feels like the need to replicate the precise machine produced edges on these modern irons. Free handing them makes some of us feel not quite like we're doing it right.

Rafael

[Derek Cohen]

The purpose of hollow grinding a thick modern blade is to reduce the amount of steel ... and effectively make it behave like a thin blade. Why not simply use a thin blade? Other than the fact that the thicker blades ould have harder, more abrasion-resistant steel (holds an edge longer) and less susceptibility to chatter, all of which are desirable. So hollow grinding brings with it the advantage of a thin blade allowing for easier honing, whether freehand or guided.

Regards from Perth

Derek