Best Way to Flatten a Sharpening Stone?
Grits
| Posted in Power Tools and Machinery on
Hello Everyone
I have a Norton multi-stone or tri-stone. It has three stones that measure about 3″ x 11″. I will appreciate any and all advise on the best way to flatten the stones.
Thanks
Grits
Replies
A few years back I purchased a coarse diamond plate. The company is "Eze-Lap". The size of the plate is about 2" x 8". It has been a while since I bought it but I think it would be equivalent to their model 71C. I fill a bucket with warm water and some Pine-sol as an oil solvent. I then set down on a stool occasionaly dipping the stones in the bucket and flatten away, holding the diamond plate in one hand and the stone to be flattened in the other.
I use this method on my Norton 2-sided stone and also my soft and #### Arkansas stones. It takes only a few minutes per stone and the result is very flat indeed. I flatten my stones about every two years or so. You might be surprised at how well this plate will remove stock from an oil stone, even though the grit is not all that coarse (equivalent to about 250 grit?).
The plate cost $65 somewhere around 1998. Current version is $71. I expect it will last a lifetime and beyond. I prefer to use the oil stones for sharpening tools, and I figure the investment in the diamond will allow me to use my stones until they are so thin they break.
LV sells lapping kits for both truing stones and planes:
http://www.leevalley.com/wood/page.aspx?c=2&p=33017&cat=1,43072
A kit consists of lapping plate, silicon carbide grits and plastic sheets.
Glaucon
If you don't think too good, then don't think too much...
I've got the Rob Cosman and David Charlesworth DVDs on sharpening. They both recommend using an 800x or 1000x grit stone to flatten stones. Rob has a dedicated 1000x stone in his pond. Everytime he uses a stone of any grit he first flattens it with the pond stone. I believe Charlesworth uses an 800x. Both just give a few rubs around and they're done. Charlesworth may also use a diamond stone.
My memory is not very good these days so caveat emptor.
Goat
Edited 11/20/2005 12:16 pm ET by GoatLand
Norton now makes a flattening stone that sells for about $24.00. It may be strictly for waterstones. I have one and it works well. I think its foolish to use a new diamond plate to flatten any stone. Silicon carbide paper is far cheaper. To the poster who recommended using a diamond plate, take a close look at it, particularly around the edges. The metal matrix that hold the diamonds will probably already be failing. I ruined a perfectly good DMT stone this way.
Edited 11/15/2005 12:43 pm ET by quartersawn
I do not agree that a diamond stone cannot handle truing an oil stone. I would agree that the bond strength is an important issue, but I think the DMT's are not made the same way as EZE-Lap. Yes, there were some of the diamond particles that came off the edges, but that was very early on and there has been no change for several years now. I would imagine that these particles were not bonded very well.
I worked as an engineer in a machining plant (Delphi Saginaw Steering). We used similarly bonded diamond truing wheels on very large industrial grinders. These grinders had 36" diameter grinding wheels that were trued up about every 50 cycles with the diamond. One diamond truing wheel would outlast over 100 grinding wheels. I don't remember these truing wheels ever being replaced unless there was a product change that required a different profile to the edge of the grinding wheel.
Thanks for that very informative response. Yes there is an obvious difference in those two brands of diamond stones. Many articles on sharpening speak of trueing waterstones with diamond plates, etc. Based on my personal experience, I am staying with the Norton trueing stone and leaving my diamond honing stones for their intended purpose. Have you ever checked your diamond plates for flatness? Apparently that has been a real issue, at least in the DMT brand.
Whatever it takes to get the job done...and leaves you feeling good about it.
I just now grabbed my 2x6 Eze-lap stone and a 4" Wood River engineers square. Laying the blade along the stone, I cannot pass a 0.0015" feeler guage under the blade anywhere along its' length.
Edited 11/20/2005 8:33 pm ET by mlbfreestyle
This is my theory of why a diamond lapping plate such as DMT or EZ-Lap is at risk when used to flatten a waterstone: In the manufacturing process, the diamond crystals are bonded to a steel backing plate by a nickel matrix. I have no idea of how this is accomplished, but I have seen diagrams in their literature illustrating this. When used to lap steel, only the diamonds contact the steel because they protrude three-dimensionally above the metal matrix. The diamonds abrade the flat metal object because they are obviously harder. However, when using the diamond coated surface to flatten a waterstone, you are encountering a material that is designed to abrade metal itself ( the waterstone). The waterstone is soft enough that it's abrasive gets in between the diamond crystals and cuts into the nickel matrix that holds the diamonds. When the softer nickel metal is worn away, the diamonds are released and eventually the effectiveness of the lapping plate is very much diminished. Anything that is used to abrade another abrasive surface will be sacrificial to a greater or lesser degree.
This is based on conjecture and I really have no microscopic proof. I would like to hear from one of the manufacturers of diamond lapping plates in this regard. Personally, it makes no difference to me because I seldom use my set of DMT stones now that I understand both the scary sharp and waterstone methods of sharpening, either of which is better suited for woodworking cutting edges, in my opinion.
Thank you for that excellent explanation.
FWIW I think I saw a post from a mfg on another forum a year or two ago, stating that the extra coarse grade would not be at risk. Unfortunately I couldn't find it with a quick google ... ;-(
-robert
Just for another point of view, I use a piece of scrap granite (from the dumpster of a local coutnertop company) and 80 grit SC abrasive, which from a lapidary house, is quite inexpensive. I use these on my Shaptons. I do not use oil stones to speak of, and not ever for honing an edge tool. This is quite fast. Use a little water, and thoroughly rinse the stone afterwards. Use the whole granite so it does not become dished.Alan
http://www.alanturnerfurnituremaker.com
Thanks. I believe that's what I saw Deneb if L-N using at a woodworking show. I didn't think to ask him what compound he was using on the granite. 80 SC sounds like just the ticket.
-robert
Another low-budget option:
get a bag of fine sandblasting sand (it will be a lifetime supply) and use it as an abrasive with water on a cinder block, granite scrap, or flat piece of concrete. It will cut very fast. When I hit upon this idea, I started flattening my stones much more often, because it is so fast. For the fine polishing stones, sandpaper on glass or a granite tile is a good final step to smooth the stone.
If float glass is hard to find, a 12" square marble or granite tile works pretty well with silicon carbide, too. There are building supply liquidators here in Milwaukee called HOBO (stands for Home Owner's Bargain Outlet) and I got a black granite tile for about $4.00 so I just soak the paper and sharpen away.
"I cut this piece four times and it's still too short."
My DMTs have floated away with eh schwarf of the water stone. I guess I could keep buying them and using them just to see if they have fixed the problem, but...
Oil stones are a whole other mater. I use SC paper.
The evidence of real world experience trumps theory in my book any day, especially when the theory is a mfg saying "it shouldn't be a problem" - LOL.
Thanks! -robert
Grits,
Allow me to offer a different possibility - one that I've used for years. I use a cinder block. While the block is very rough it is amazingly flat.
If I want to work inside I simply soak my stone then rub it back and forth on the block. If I want to work outside I place the block under a spicket and run the water over both while I rub the stone back and forth. Either way, I rinse the stone and block when done.
To ease your mind, place a straigh edge on a cinder block or patio stone and try to slide a feeler guage underneath. I think you'll be surprised.
As I've said, I've used this method for years. I always seem to have a block around the farm so I can't beat the price. Even if I had to buy one it won't be more than a buck or two.
Good luck,
Bill
I agree with Bill. I have used a cinder block for years to flatten waterstones. My flattener came free with the purchase of my home (okay, maybe not so free). I have never had to replace it, and doubt that I ever will. I put the cinder block on a piece of plywood with four spare casters. It is easy to move the cinder block out of the way when it is not being used.
I don't know if it works with oilstones, though.
Elliott
Works with oilstones, although I did find that the flat concrete I used got blunt after a few times (had to change to the front tap to get a different block)
I wonder if you could glue some sandpaper to a piece of float glass and use that to flatten the stones? :)
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
PlaneWood
Plane-yes, and you don't even have to glue it on-just wet the under and plonk it down-silicon carbide 180grit is good.
What a strange lot we woodworms are-some use stones to flatten other stones, others risk damage to precious diamond plates, others scrape on the pavement,and then there are those who use abrasive paper to sharpen on .....Philip Marcou
Thank You
I like all the ideas. The cinder block is interesting. I grew up in the ready mix concrete business. My father manufactured concrete block. I understand why they are flat. Another idea. Pour concrete in a mold (form) with a flat bottom. That may be the ticket. Concrete should be a little harder than a cinder block.
I have had the above mentioned stone for at least fifteen years. It has been used, mainly, for kitchen and hunting knives. I is just now showing some wear. I finish most if my edges on a "HARD" Arkansas stone. The Arkansas stone was my fathers and no telling how old it is (since it was mined). It is a Norton in a wooden case. I is so hard it feels slick. In my opinion, a hard Arkansas stone is the last work on honing an edge.
Thank you all for your ideas and advise. You folks in this forum are great and a lot of fun.
Grits
It isn't the hardness, but the abrasiveness that counts. A true cinder block is way too soft, but either a concrete or "Solite" block is just the ticket. Costs about $1.25 at BORG.
I agree. We also made solid concrete blocks, pipe, stepping stones, etc. It was done the hard way. We had a gillion steel forms. I remember them being oiled, poured, vibrated, and then beat on to get them loose. That was in the fifties and sixties. A great place to hang out before I was old enough to work.
Grits
The glass plate and sand paper works well you can also use a metal drywall screen on the glass.Troy
Wow, that's a great idea. Thanks for kicking that in!
I have King Waterstones, I flatten them often when sharpening my blades, especially if new to me. I use the glass and sand paper method. I got a 1/4x12"x12" piece of glass for my local glass supplier (Portland Glass). I think it was about $10. I use 220 Wet/Dry Paper. I either use 1/2 Sheet per stone or Start with the Finest stone and work to the Coursest. I use water to hold the paper in place and lube the stones
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