Flattening waterstones

[Bob Jones 5443]

I'm guessing this topic has been visited and revisited over and over on SMC, but I'm still new here so I'll ask my question anyway.

I flatten my Norton and King waterstones on wet/dry 220 grit sandpaper on a granite surface plate. Now that I'm sharpening much more regularly, I'm going through sandpaper sheets at a noticeable pace. I'd always heard that in the long run sandpaper is more expensive than other methods, but that was less relevant when I was sharpening less frequently.

I did hear on this site that folks discouraged me from looking into the Norton flattening stone, so my plan is to continue with the wet/dry paper (plus, I already have the surface plate). The five-sheet packs are 7 or 8 dollars, though. I want to choose one brand and buy the largest pack I can find (probably 100 sheets), so I don't want to get stuck with something that doesn't work well.

Who can help me make sense of the variables here? It looks like silicon carbide may be better at this grit than aluminum oxide. Agree? This is just for the waterstones. For me the other attributes that matter are: easy to reuse, gets flat again the next time on the plate, lasts through several flattenings, doesn't slide on the plate, and resists bunching up. Finally, I'd like to get the price down below $1 a sheet.

Any other wisdom is welcome, even the contrarian view on the sandpaper method.

[David Bassett]

Lots of options.

Classic cheap is dry wall screen. It's an open mesh so it won't load as fast as sand paper. That said, it too adds up over time.

I think most people end up with a diamond plate. It costs more up front, but lasts so much longer for stone flattening it's eventually cheaper. You can go real cheap with generic plates, e.g. Amazon Marketplace direct from China, but while some folks have happy, others have reported serious flatness issues. You can go really expensive, e.g. DiaFlat, Shapton, Nanohone etc, and pay a premium for better than you really need. Though many that have gone that route rave about the quality. IMO- the sweet spot is in between. The standard "go to" plate is an Atoma 140 or 400. You can get them in reasonable size off of Amazon for $65-75 these days. (Used to be Stu's Tools from Japan was the only reasonable source in the US, but he's closed down and other vendors have filled in.) I think the store brand flattening plate from Japanese Knife Imports is an even better choice for flattening. I trust Jon, the owner, to ensure quality control and can vouch the plate does it's job easily and well. For $55 it's the cheapest I know of (without the no-name lottery on Amazon or eBay) and it's in stock:

https://www.japaneseknifeimports.com/collections/sharpening-accessories/products/diamond-flattening-plate

[Mike Henderson]

I use a DMT diamond plate. I find it produces an adequately flat stone. They last a very long time - I've had, and used, mine for at least 10 years and it still works fine for flattening my Shapton stones.

Mike

[Jim Matthews]

Auto supply or Grainger should offer coarse wet/dry sandpaper at reasonable cost.

Your next nearest solution is a large diamond plate.

If you're like most of us, a hobbyist, sandpaper to occasionally flatten a stone shouldn't be pricey.

You can probably wash the sheet off, between uses.

[Paul F Franklin]

Klingspor woodworking shop has 50 sheet packs of SC wet/dry. Their stuff is generally good quality.

[Rafael Herrera]

I use silicon carbide grit from Lee Valley on a piece of thick glass. I get my carborundum and washitas flat faster than using sandpaper.

[Robert Hazelwood]

If you are doing enough sharpening that the sandpaper is expensive/annoying then go for a diamond plate.

A diamond plate is useful for other things too, for when you need a very hard surface stone or need to cut HSS or carbide, etc.

[Tom M King]

I have Atoma replacement sheets-140 and 400-on a granite surface plate. I think they are 100x200 mm, or about 4x8 each. I used sandpaper for a long time, and then bought some Diamond plate(forget the manufacturer) that wasn't flat, so I went with a surface I know to be flat.

[Winston Chang]

I think sandpaper is too much time and effort -- much more convenient to use a diamond plate. Make sure it's flat, though. I've had DMT plates and a Trend plate that were not quite flat, and it can result in a lot more work sharpening, and poor results. Best to get one from a retail store where you can return it if it's not flat.

Another option: if you don't want to spend much money, you can make flattening stones out of bricks. You'll need three of them, plus some silicon carbide powder. They will be extremely flat. I made a thread about it here: https://sawmillcreek.org/showthread.php?273412-Making-flattening-stones-with-3-bricks

One thing to note about the bricks: In the sharpening guide where I read about the idea of using three bricks, the author recommended cutting grooves in them with an angle grinder. I don't have an angle grinder, so I didn't cut grooves in the bricks, and I eventually started having issues with stiction.

[Mike Cornwall]

I’ve read that getting a matching pair of stones and rubbing them together is the best way to get them flat without making them cut coarser or finer, but you have probably read that too. It seems like with anything related to sharpening, the thing to do is pick a way and get good at it, and that’s another thing you’ve probably read.

[David Bassett]

... pair of stones ....

Using two doesn't make them flat, it makes them complementary surfaces often with one concave and one convex. To insure flat you need three stones and you rotate them so each matches the other two.

Trust me, a decent diamond plate is much less mess and hassle.

[Mike Henderson]

I’ve read that getting a matching pair of stones and rubbing them together is the best way to get them flat without making them cut coarser or finer, but you have probably read that too. It seems like with anything related to sharpening, the thing to do is pick a way and get good at it, and that’s another thing you’ve probably read.

David's right. With two stones you get two conforming surfaces which will most likely be one concave and one convex. You can get a flat surface using three stones and a specified rotation when you rub two at a time together.

Mike

[William Fretwell]

Have used a diamond plate for years, it is not much larger than the stones so I bought a larger double sided CBN plate, certified crazy flat. The coarser side is very aggressive, the fine side works well, the increased size feels good. I used both today, the CBN plate is faster. You need to put it somewhere warm and ventilated to dry or it will rust. The other benefit is the coarse side can be useful for other re-shaping projects for rapid removal.

[Warren Mickley]

Two stones are sufficient if you know what you are doing. If you are just going to rub mindlessly while watching television, yes you can end up with one slightly concave and one convex. Invariably, however, both stones are slightly concave so they can be improved by matching up their high spots. And if you start to get one stone somewhat convex, you can alter your rubbing pattern.

Day to day, the danger is having a stone concave across the width. This we can manage by how we sharpen: letting a plane iron or chisel hang over the edge will cause the wear to even out.

[Mike Cornwall]

I’ve read those things, as well. I hope everyone has found or is about to find the gear that answers all his prayers.

[Chris Fournier]

I'm guessing this topic has been visited and revisited over and over on SMC, but I'm still new here so I'll ask my question anyway.

I flatten my Norton and King waterstones on wet/dry 220 grit sandpaper on a granite surface plate. Now that I'm sharpening much more regularly, I'm going through sandpaper sheets at a noticeable pace. I'd always heard that in the long run sandpaper is more expensive than other methods, but that was less relevant when I was sharpening less frequently.

I did hear on this site that folks discouraged me from looking into the Norton flattening stone, so my plan is to continue with the wet/dry paper (plus, I already have the surface plate). The five-sheet packs are 7 or 8 dollars, though. I want to choose one brand and buy the largest pack I can find (probably 100 sheets), so I don't want to get stuck with something that doesn't work well.

Who can help me make sense of the variables here? It looks like silicon carbide may be better at this grit than aluminum oxide. Agree? This is just for the waterstones. For me the other attributes that matter are: easy to reuse, gets flat again the next time on the plate, lasts through several flattenings, doesn't slide on the plate, and resists bunching up. Finally, I'd like to get the price down below $1 a sheet.

Any other wisdom is welcome, even the contrarian view on the sandpaper method.

I buy my sandpaper from an industry wholesaler, I buy 50 to 100 in a sleeve and the price is very reasonable compared to retail. I'm sure that you can do this too. I flatten my stones on 320 grit over granite. And often I'll flatten my finer stones on my freshly flattened 800 grit saving the sandpaper.

[ken hatch]

Forgive me but I can't help myself. I always find flattening waterstone threads amusing. The easiest and cheapest way around the flat waterstone problem is to use Arkansas stones. Full discloser, I have and on occasion use waterstones but 90% of my sharpening is on either oil stones or JNats, neither of which, if used properly, need much flattening. Just to add, at least on the cutters I use, are as fast if not faster than waterstones if you include the waterstone monkey motion.

ken

[Chris Fournier]

Forgive me but I can't help myself. I always find flattening waterstone threads amusing. The easiest and cheapest way around the flat waterstone problem is to use Arkansas stones. Full discloser, I have and on occasion use waterstones but 90% of my sharpening is on either oil stones or JNats, neither of which, if used properly, need much flattening. Just to add, at least on the cutters I use, are as fast if not faster than waterstones if you include the waterstone monkey motion.

ken

I haven't found Arkansas stones to be cheap! I do use Arkansas slip stones with my carving tools for the reasons that you state. Well except for the cheap part!

[Andrew Pitonyak]

Read this:

http://www.sawmillcreek.org/showthread.php?175329-How-do-you-flatten-Japanese-Water-Stones&highlight=atoma+1200


Pay special attention to this particular post in the thread:

https://sawmillcreek.org/showthread.php?175329-How-do-you-flatten-Japanese-Water-Stones&p=1803493#post1803493

Bottom line, for most water stones, do not use sand paper. If you purchase a diamond stone, get one that is larger than your stone if you can, it is less likely that you will take it out of shape if you do that. I tried to flatten a really really touch stone with a smaller diamond plate, and it was not effective.

[Bob Jones 5443]

Andrew, thank you for this informative reference. I knew the topic must have been featured on these pages.

Well, Stu Tierney certainly has developed a position on this. However, I did see, imbedded in his narrative, a disclaimer about Norton and King waterstones somehow avoiding the calamity he predicts from using the sandpaper method.

After I carefully run the 1000 King or 8000 Norton stone over its own region of a 220-grit paper sheet, I rinse the stone and rinse the sheet. As I rinse the stone I can feel its surface, and I do not notice any foreign grit lingering on it. I usually reuse the sheet about three times before discarding it, and through those reuses the faint color remaining after the rinsing shows me where the 1000 goes and where the 8000 goes.

Old habits die hard, and when established experts do recommend wet/dry paper, and since I've used the method in the shop of one of those experts, as well as on my own for over a decade, I think I'm going to continue to pour my money down the wet/dry paper drain for the foreseeable future. Wish me luck.

[Andrew Pitonyak]

Andrew, thank you for this informative reference. I knew the topic must have been featured on these pages.

Well, Stu Tierney certainly has developed a position on this. However, I did see, imbedded in his narrative, a disclaimer about Norton and King waterstones somehow avoiding the calamity he predicts from using the sandpaper method.

After I carefully run the 1000 King or 8000 Norton stone over its own region of a 220-grit paper sheet, I rinse the stone and rinse the sheet. As I rinse the stone I can feel its surface, and I do not notice any foreign grit lingering on it. I usually reuse the sheet about three times before discarding it, and through those reuses the faint color remaining after the rinsing shows me where the 1000 goes and where the 8000 goes.

Old habits die hard, and when established experts do recommend wet/dry paper, and since I've used the method in the shop of one of those experts, as well as on my own for over a decade, I think I'm going to continue to pour my money down the wet/dry paper drain for the foreseeable future. Wish me luck.

I expect that problems using sandpaper are the exception not the rule, but the advise was repeated by three different water stone manufacturers. I do own numerous diamond stones, so it is mute for me. I probably used sandpaper on my two Bester stones and one of my Shapton stones many years back before I owned a diamond stone. As Stu noted, he was initially confused as to why it might matter. It is probably more important that you understand the why so that you can make your own decision and it allows you to look for signs that you might have a problem. I expect that any of the mentioned problems should be curable with a diamond stone so I am not entirely certain what the big deal is provided you recognize the problem. I also expect if you are able to identify the problem, you can easily fix it by buying a diamond stone or, gasp, even rubbing it on your driveway or sidewalk (with water).

I thought he was pretty clear as to why some waterstones are expected to not have the problem and others might. Not having the problem was directly related to the binder. There is no "you will have a problem" unless it is in the context of statistically speaking, it is highly likely that you eventually will if you do it often enough. I that Shapton stones have a hard binder. My Bester stones are listed as "super ceramic", whatever that means.

As for established experts, are they established with respect to woodworking skill, or the science related to the stones? I have been given a lot of wrong (or bad) information by experts. In my case, it is usually "that cannot be done", which is very different than your experts who are problem saying "I have been doing this for years". I had a professional sharpener tell me that it is not possible to sharpen a certain type of steel on an Arkansas stone.... I had no experience at that point other than having just purchased some, so I did some research. Oddly, the literature that I searched suggested otherwise. Later, I took the steel that I was told was not possible to sharpen on my Arkansas stones and I raised a bur. I now routinely sharpen it on my Arkansas stones. Note that for bigger jobs, I will turn to diamonds and also that not all Arkansas stones are equally good at cutting. I have not yet tried to sharpen S35VN or even PM-V11. I have seen suggestions that S35VN likes to be sharpened on diamonds because of the surface that it leaves.

In the unlikely event you are ever in the middle of Ohio, stop in and you can try some of my stones (natural and otherwise) and then we can eat some food.

[Chris Fournier]

What utter nonsense. Abrasive attached to paper won't work but abrasive either in a binder or dry will? BS and BS big time. I've used sandpaper to flatten water stones for over 20 years with no ill effect. I've also used lapping compound and it ain't magic, it's basically loose abrasive particles. I'll use lapping compound for lapping, say fresh valves to fresh cut valve seats in an engine, why on earth would I need it to lap a water stone? Sorry but this is complete nonsense. And when you pour these abrasive particles on your reference surface and start to lap the stone what do you think is happening to your reference surface? You're abraiding it!

[Andrew Pitonyak]

What utter nonsense. Abrasive attached to paper won't work but abrasive either in a binder or dry will? BS and BS big time. I've used sandpaper to flatten water stones for over 20 years with no ill effect. I've also used lapping compound and it ain't magic, it's basically loose abrasive particles. I'll use lapping compound for lapping, say fresh valves to fresh cut valve seats in an engine, why on earth would I need it to lap a water stone? Sorry but this is complete nonsense. And when you pour these abrasive particles on your reference surface and start to lap the stone what do you think is happening to your reference surface? You're abraiding it!
No one said it would not work... As will flattening on concrete