# Diamond stones for chisels/plane blades



## John Loftis (Aug 20, 2015)

Hi all, I'm nervously poking my head out from my butcher block hidey-hole. I use power tools 99% of the time, but I'm learning more about hand-tool work (affectionately referred to as neanderthals) in woodworking. Just got back from a hand-tool workshop and I'm now convinced I need to get my act together when it comes to sharpening my chisels and hand plane blades. The method the woodworking school recommends is to work through 300, 600, and 1200 grit diamond stones, then use a translucent Arkansas stone, then polish with a leather strop glued to a chunk of wood with a little jeweler's rouge. The instructor uses hand tools all day, every day, and he is very good at sharpening... but he's probably not an expert on sharpening stones themselves. I'm not sure if woodworking sharpening processes/requirements would be identical to kitchen knife processes/requirements, but I thought I'd reach out here to get some input. 

The tools are mostly Lie Nielsen out of A2 steel. From their website: "Our blades... are hardened at Rockwell 60-62, to provide a long lasting blade. Careful heat treatment involves a 20-hour soak at -320º F (cryogenics) and double tempering. This results in a fine grain structure which allows the blade to take a very fine edge. The final step is a full surface grinding of the top, back and cutting edge, giving a smooth flat surface requiring little honing before use."

If I'm allowed to post links, I can share the woodworking school's video on their process for sharpening chisels if anyone wants to see it. 

His process definitely works. I guess my questions are:
1) Is there a 'better' way or is this process a good methodology? 
2) for tool steel (that will be repeatedly banged into/chewing into hardwood), will there be a significant difference in one set of diamond stones over another? I can justify about $200 for a set of stones, since hand work is mostly for fun rather than for profit. 
3) would welcome recommendations on stones. I could explore waterstones as well but I'm a little less interested in those because of the need to lap them and soak them. 

Thanks!
john


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## Dardeau (Aug 20, 2015)

I use the JKI diamond stone set followed by an Ohira suita.


The JKI set is a little pricy, but is definitely worth it. Almost everything I sharpen passes over the 1k stone.


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## psfred (Aug 20, 2015)

Diamond stones are fine for A2, but I suspect you will get a better edge if you use a 6000 grit waterstone instead of a translucent Arkansas -- I seriously doubt that stone is doing anything at all to the edge, A2 is far to tough for an Arkansas stone. I would also use green chromium oxide on a strop for the same reason.

I have found that woodworking tools, unlike kitchen knives, need to have as near perfect an apex as possible. Not only that, but plane blades do not wear like knives, either -- the back of the iron must meet the bevel in a straight line, and since most of the wear on the iron is actually on the back, not the bevel, it will be not only rounded over on the edge but abraded away just above the edge. If you do not remove this divot, either by grinding on the back or removing steel from the bevel, the edge will look fine and be nothing more than a whisper of wire edge and will NOT be sharp. Abused tools can take a long, long time to get right -- I've gotten never sharpened plane blades on used planes that are visibly rounded. Must have take enormous effort to force through wood.

My personal system is to use diamond stones for heavy work (very dull blades, nicks from nails or small knots, etc), but waterstones at 1000 grit or above. Bester 1200, something in the 3000 grit range (I have several, recently I've been using a 4000 Naniwa superstone), a 6k King (to be replaced with a Suehiro 5K Rika soon) and a Kitayama 8K, followed by light stropping on wood charged with green chromium oxide half micro wax. Done properly with will produce a mirror finish on both sides.

All of your stones must be PERFECTLY flat, which means flatten every use and probably during use, otherwise you will get a blade with dull spots on the edge where the stones are grinding differently. This is one reason many people like to use diamond "stones" -- they don't dish. Nothing more irritating than to find a plane blade is only polishing in the center on a fine grit stone because the coarser stone you just used was going hollow.

You must use very light pressure on diamond stones on A2 blades, they are somewhat brittle, more so that carbon steel which is typically less hard, and it's possible to produce micro-cracks in the edge on coarse stones. This will then result in micro-chipping of the edge in use, especially on end grain. 

Use VERY light pressure when stropping on leather -- it's quite easy to erode the apex if you press down from the "rebound" in the leather. It compresses with pressure and springs back as the blade moves, and this will round off that edge in no time at all! That's why I use wood.

A2 takes a long time to get sharp, it's quite abrasion resistant, but it will last "work sharp" ten times as long as carbon steel or O1.

Peter


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## Adrian (Aug 21, 2015)

You have got top notch chisels there. I have a set of six LNs and I sharpen them very satisfactorily on water stones - not the same ones I use for my kitchen knives, but that is only because the workshop is not near the kitchen. I also have a few Japanese chisel, that are probably fractionally harder. Key thing with chisels and plane blades of course is you want them flat and square. It is all too common to see chisels with uneven bevels. As I am not as good at sharpening chisels as I am at kitchen knives, I use a jig to set the beve angles and this makes sure I keep the edge perfectly positioned. This is also why diamond plates are a good idea - they stay flat and ungouged.. I have never used an Arkansas stone as I live in the UK. The guys commenting above, psfred especially, have given excellent advice.


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## John Loftis (Aug 21, 2015)

Thanks, guys. I was curious about the Arkansas stone... I've never used one. I had an old Norton combination waterstone, which I can't seem to find anywhere in the shop, and I had to flatten it with a diamond stone after every use. Which begs the question, why not just use diamond stones instead? 

One thing to clarify, I have 3 Lie Nielsen hand planes with the A2, then a handful of miscellaneous old Stanleys that I picked up at garage sales or whatever with whatever steel those have. I have some Two Cherries gouges but my go-to chisels are a cheap set of Narex chisels with chrome manganese steel (RC 58). I'll upgrade the chisels when I get a couple pennies to rub together. Anyway, the steel in my hand tools runs the gamut. 

So maybe a better method would be to work through the diamond stone grits, then swap out an Arkansas stone for a high grit water stone (say in the range of 3k-8k), then a light polish with the strop/rouge. 

Here's Frank Strazza's method for sharpening chisels. Might be interesting to some: http://www.sustainlife.org/store/online-courses/sharpen-chisel/
At the woodworking school, I spent about 15 minutes flattening the back of one of my cheap Narex chisels on a diamond stone. It took forever. 


BTW, I'm seriously eyeing the new Lee Valley chisels out of PM-V11... reviews have been great on those. Do I NEED them??? No. Want? Oh yes! 

Dardeu, I saw the JKI thread on the diamond set. They look incredible, but I'm an impoverished woodworker. Maybe someone would barter for a kick-butt butcher block.


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## Adrian (Aug 21, 2015)

Those Verital PM chisels look very good - but if you want really hard blades and are happy to pay similar prices for top quality, you might do well with Japanese chisels? The PM V11 is rockwell 61/62 and a good hard Japanese chisel will be 66/67. They feel different in the hand but I find they are great for heavy duty topping in hard timber, knots etc. I should add I only do this as a hobbyist and in a small way.


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## psfred (Aug 21, 2015)

You will only use a Japanese chisel for chopping or mortised in hardwood once. Likely you will give up trying to get the chips out of the edge before you run out of hardened steel. Softwood without knots only, if you are doing anything else use a different chisel. Very brittle, as they are indeed carbon steel at RC 66-67.

You can use a good Arkansas stone with A2, but unless you use it only to make a final microbevel, it's going to take forever, and some stones will not cut it at all -- they are natural stones and quite variable. Some of them don't seem to mark the steel at all, and the novaculite is about the same hardness as the chromium carbides in the steel, so you risk ripping them out rather than sharpening the blade. Same effect as sharpening German soft steel knives at too high a grit.

You should also understand that diamond stones and waterstones require MUCH less pressure to cut that Arkansas. To get a translucent Akransas stone to polish A2 you have to lean on it, doing so on diamond will strip the diamonds from the nickel plating and will gouge waterstones!

I seem to sharpen my plane blades to somewhat finer grit that is suggested -- 6K or 8K followed by half micron grit on wood. I still don't have many of them as sharp as I'd like, due to excessive wear as acquired.

Peter


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## John Loftis (Aug 22, 2015)

I had a quick e-mail exchange with Jon at JKI and he is slammed right now but said he'd offer his thoughts on sharpening stones next week. Look forward to hearing what he has to say. I confess diamond stones are a little arcane and overwhelming to me. 

My understanding is Japanese chisels can be a superb addition to the shop, generally being used as paring tools (shaving a hair off tenons, etc). For the type of work I do, I'd need a more traditional western style chisel most of the time.


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## Tall Dark and Swarfy (Aug 22, 2015)

The Shapton Glass line was supposedly designed with the Lie Nielsen A2 as the target blade.


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## BHolcombe (Aug 22, 2015)

psfred said:


> You will only use a Japanese chisel for chopping or mortised in hardwood once. Likely you will give up trying to get the chips out of the edge before you run out of hardened steel. Softwood without knots only, if you are doing anything else use a different chisel. Very brittle, as they are indeed carbon steel at RC 66-67.
> 
> You can use a good Arkansas stone with A2, but unless you use it only to make a final microbevel, it's going to take forever, and some stones will not cut it at all -- they are natural stones and quite variable. Some of them don't seem to mark the steel at all, and the novaculite is about the same hardness as the chromium carbides in the steel, so you risk ripping them out rather than sharpening the blade. Same effect as sharpening German soft steel knives at too high a grit.
> 
> ...


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## BHolcombe (Aug 22, 2015)

John,

I have separate procedures for A2/O1 blades and Japanese blades.

For A2 I will prep the blade with diamonds followed by Chosera 1k and 3k. Then I refine the edge with a Naniwa snow white and then a Sigma 13k.

For 01 I do the same, but with 01 you can finish with Arkansas stones however I do not have personal experience in doing so.

I follow up this with a clean strop to ensure the wire edge is gone.

For Japanese blades I do this entire procedure but finish the edge by hand on a Shinden stone to refine the edge and finally follow up with a clean strop (no paste)

Having had Lie Nielsen blades and still have them in my planes.they are OK, I like Japanese tools much better, especially the chisels. Kikuhiromaru make excellent chisels that are not insanely expensive, their white steel #1 chisels with a 30 degree bevel will serve you well in hardwoods.

I have/had chisels by Lie Nielsen, Blue Spruce, Stanley, Koyama-ichi (white and blue #2), Kikuhiromaru (white #1), Ouchi (white #2), Yamahiro (white #1) and Tasai (special made blue steel). I sold the LN's, I keep the Blue spruce because they're so damned sexy, the stanley's are for rough construction (nail worries), and all of the Japanese listed are wonderful to use.


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## John Loftis (Aug 28, 2015)

Had a great conversation with Jon at JKI this afternoon. I took notes as he spoke, so hopefully won't mis-characterize what he said too much. A couple key points:

- the goals/methods for sharpening woodworking tools are different than those of kitchen knives
- with a knife, you want a little 'bite' in the edge. It helps with feedback/feel. With chisels/planes, you don't. You wan't it smooth and sharp. Honing is definitely a plus with chisels/plane blades.
- with woodworking stones, you generally want hard stones that stay flat. Softer stones that dish a bit might be better for knife work, but are to be avoided in wood tool sharpening. Hard stones are generally less aggressive and might take a bit longer to sharpen. 
-diamond stones are fine, but you want 'harder' diamond stones. 

I also talked to Frank Strazza today at Heritage School of Woodworking, and he uses the course, fine, and extra fine DMT dia sharp stones plus arkansas translucent plus honing with chromium oxide. 

John


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## JBroida (Aug 28, 2015)

diamond stones are fine, but if possible, the ones that use a binding agent are better, when compared to DMT-like ones, with the abrasives sitting on the surface. But, its not to say the DMT-like stones dont work well.


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## aboynamedsuita (Aug 28, 2015)

Hey John, if you're still debating the Lee Valley purchase they have a free shipping promo on until the 31st

http://www.leevalley.com/us/home/page.aspx?p=60912&c=


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## BHolcombe (Aug 29, 2015)

Atoma diamond plates are fine....DMT leave something to be desired.

Pretty much on target, basically with Japanese tools you are working with flat bevels with a tiny micro bevel, so you do not need to dish the stone to work toward the shinogi line like you would for a single bevel knife.


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## Chezpopp (Aug 30, 2015)

My grandfather was a woodworker. He always used a belgian coticule to finish his hand planes and chisels. It was great because I inherited them and use them on my straight razors. He loved the coticules. He used mainly those. Some rougher stones for really out of shape stuff. Normally though he just slurried it up and finished w water only. Stropped on linen and leather. He did a lot of very fine detail stuff.


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