Power back flattening on the cheap - options

[Aaron Rappaport]

There's been a fair amount of discussion here about back-flattening using either the 10" Grizzly Tormek (wet wheel grinder) clone or the Worksharp 3000. How about their smaller siblings? Has anyone used either the 8" Grizzly wet wheel grinder or the Worksharp 2000 to flatten the backs of chisels and plane blades?

[john brenton]

My DMT xtra coarse/coarse stone does it in like 2 seconds. I know that wasn't your question, but just thought I'd throw that out there. I was really impressed by how quickly it removes metal on the x-coarse, and how nice and uniform the coarse prepares the surface for honing. 10" stone for $80...to me it's worth every penny.


There's been a fair amount of discussion here about back-flattening using either the 10" Grizzly Tormek (wet wheel grinder) clone or the Worksharp 3000. How about their smaller siblings? Has anyone used either the 8" Grizzly wet wheel grinder or the Worksharp 2000 to flatten the backs of chisels and plane blades?

[Johnny Kleso]

I built my own unit
http://home.comcast.net/~rexmill/sharpening/MKIII/MKIII.html

Its still pretty slow even with starting with 100 grit 8" paper with a really bad blade..

The best bet is to stay away from bad old blades and just buy a new Stanley blade and use a hand stone or Loose Grit in another artical I have on the site..

[Gary Herrmann]

If you've already got one - belt sander.

[James Taglienti]

a stationary belt/disc sander works alright. I got a benchtop one from delta and it worked for a while until i popped the belt on it. Havent got a new one yet. I think it was a hundred bucks for the machine, and I used it (abused?) for about a year.

[David Weaver]

$20 of 100 grit diamonds (dry, not in a paste), a $20 kanaban and a self-made iron holder (free).

That's the way to go if you're going to grind a large amount and want a back to be flat (no dubbed areas and no really deep marks).

You can remove metal much faster than a tormek wheel (which just like the wheel surface, will become slow to cut after a while, and you can't keep it flat once you start hitting it with a grading stone), and more economically than beating up sandpaper on a power sharpener.

You'll save your fingers and possibly fingertips (they wear off on a stone, too!) from trying to do it by hand.

[john brenton]

What is a "kanaban"?


$20 of 100 grit diamonds (dry, not in a paste), a $20 kanaban and a self-made iron holder (free).

That's the way to go if you're going to grind a large amount and want a back to be flat (no dubbed areas and no really deep marks).

You can remove metal much faster than a tormek wheel (which just like the wheel surface, will become slow to cut after a while, and you can't keep it flat once you start hitting it with a grading stone), and more economically than beating up sandpaper on a power sharpener.

You'll save your fingers and possibly fingertips (they wear off on a stone, too!) from trying to do it by hand.

[Zach England]

I admit to having taken my handheld belt sander, setting it on the lowest speed and "mounting" it in my bench vise to flatten plane soles and iron backs.

[David Weaver]

What is a "kanaban"?

Mild steel plate, at least I think it's mild steel.

Various retailers sell them for about $20-$25.

I know I've shown a picture of a very dirty nasty iron holder on here before. They are basically a 2x4 with two bolts and washers through the middle. The bolts just go through the slot on an iron and when tightened, they hold it tight to the 2x4. You can lean on it a lot more flattening something than you can put pressure on with your fingers.

I have flattened several dozen irons on mine over the last year, including some very nasty pitted old double irons and I still have at least 3/4ths of the diamonds left. I was using 3x on granite before. That works well, but if you don't stick it down you have dubbing, if you do stick it down, you have to fool with getting it on and off to replace it, and you have to remove the swarf with it.

With a light lube of wd40 or something similar on a kanaban with fairly coarse diamond - you stop when you're tired, no changing anything.

[Randy Briggs]

What is a "kanaban"?
A japanese flattening plate. Piece of flat steel that you use with diamond paste, loose grit (SC or diamonds), etc. TFWW sells them.

Another option is to buy the clearance priced pieces of O1 tool steel that Victor Machinery sells - I'm using them to make a set of different grits and it is far more cost effective.

[Randy Briggs]

My DMT xtra coarse/coarse stone does it in like 2 seconds. I know that wasn't your question, but just thought I'd throw that out there. I was really impressed by how quickly it removes metal on the x-coarse, and how nice and uniform the coarse prepares the surface for honing. 10" stone for $80...to me it's worth every penny.
Maybe its just me being too much of a perfectionist (it is) but I have been thoroughly disappointed with the DMT C/XC DuoSharp plate. I've got the large one and I am amazed at how LONG it takes me to flatten backs. I usually go to SS on my surface plate and then go back through the stones. I even got the XXC DiaSharp stone and it doesn't seem to be as fast as SS. Now the Sigma Power 120 stone....

I have the WS3000 and can't seem to stop from dubbing a corner when using it for flattening. A foot pedal has helped some. I would think the WS2000 would be ok for the initial rough flattening and then moving to SS or stones for polishing.

[David Weaver]

Maybe its just me being too much of a perfectionist (it is) but I have been thoroughly disappointed with the DMT C/XC DuoSharp plate. I've got the large one and I am amazed at how LONG it takes me to flatten backs. I usually go to SS on my surface plate and then go back through the stones. I even got the XXC DiaSharp stone and it doesn't seem to be as fast as SS. Now the Sigma Power 120 stone....

I have the WS3000 and can't seem to stop from dubbing a corner when using it for flattening. A foot pedal has helped some. I would think the WS2000 would be ok for the initial rough flattening and then moving to SS or stones for polishing.

The trouble with dubbed corners is that you have to get rid of it somehow, either by grinding or by flattening it all out on the next step. Either takes a fair amount of time and effort.

I am also in the category of people who killed a DMT only with hand pressure, and I didn't think I was pushing that hard. I liked how it worked when it was new. I guess I got a couple of sets of chisels and a couple of plane blades through mine before it pooped out. I will flatten anything that has enough metal left in the lamination or enough thickness left in a solid iron to be still useful after flattening. DMTs are not tolerant of that kind of behavior.

The other side benefit to using loose diamonds is they will cut anything, and they will cut as fast or faster than any abrasive available and without loading. If the kanaban gets out of flat, you just lap it.

[Russell Sansom]

How does one prevent dubbing the corners with a belt sander? Or keeping front and back parallel?

[Mark Roderick]

If the kanaban (a new word for me also) gets out of flat, what do you lap it on? A bigger kanaban?

[David Weaver]

If the kanaban (a new word for me also) gets out of flat, what do you lap it on? A bigger kanaban?

A granite plate, or a long piece of float glass and sandpaper. I haven't done mine yet, but I have lapped planes made out of O1 and mild steel that were a lot bigger (and with more metal to be removed than I'll ever have to take from a kanaban), and as long as the sandpaper is fresh, it won't be a big deal.

Of course, the thing costs $22, so you could just buy another one, but you will probably be sick of buying old tools before it's that bad, anyway - it's not the final step before a polishing stone, so even if it's a tiny out of flat, when you move to an 800 stone or something after it, you will not notice.

[Johnny Kleso]

How does one prevent dubbing the corners with a belt sander? Or keeping front and back parallel?


Thats why the round versions are slower speeds than a belt sander..
It makes it eaiser to keep flat..

Myself I would rater use the side of a grinding wheel than a belt sander for aggressive stock removal..

[David Weaver]

Thats why the round versions are slower speeds than a belt sander..
It makes it eaiser to keep flat..

Myself I would rater use the side of a grinding wheel than a belt sander for aggressive stock removal..

Ditto. You only realize how much work you've made for yourself (if the corners and edges of a tool matter) after you've done the damage.

[Mark Roderick]

And so, if you have the granite plate or glass, why buy a kanaban? Why not use one of those Kevlar sheets that Lee Valley sells with the little diamonds?

[David Weaver]

And so, if you have the granite plate or glass, why buy a kanaban? Why not use one of those Kevlar sheets that Lee Valley sells with the little diamonds?

I don't know how long they last, and they're definitely not more economical in the long run. With a kanaban mounted to a block on a non skid surface, and an iron holder, you can lean *all* of your body weight on the iron you're flattening. If there is some lube on the kanaban (WD 40, etc), you won't roll it and dub the edges.

I haven't yet seen a substrate that affixed diamonds can't be separated from, and pressure like this will do it. I haven't used those sheets, so I can't say for sure that happens with them, but if I were a betting man,...

When you've finely crushed (polycrystalline) or dulled (monocrystalline) the diamonds enough, you are still going to torture yourself with dull diamonds. When the kanaban cutting slows, you sprinkle a tiny part of a fingernal's worth / snow coating of diamonds on the plate and you're refreshed again.

[Johnny Kleso]

I'd like to say I was a foreman of a diamond tool company for years and diamonds and diamond bench planes are not the best tool for flattening a steel blade IMHO

I think silicon carbide grit does a better much more cost effect job..
http://www.kingsleynorth.com/skshop/category.php?catID=1053

You can buy loose grit for about $5 a lb
You can add this to a old piece of sand paper or on top of a steel plate with some oil or a piece of flattened wood..

I do own a diamond plate but only use it for flattening bench stones..

[David Weaver]

I never did like SC as much, but I don't know as much about this stuff as you do, johnny - it definitely does still work just fine.

I just always felt like the loose diamonds are cutting keener and the swarf is more metal and less broken abrasive.

I've tried diamonds, alox and SiC on steel and cast iron, and there is a lot of broken down swarf with SiC.

You are dead on that it is dirt cheap. I think I got 2 pounds of SiC for $10, and a pound of AlOx 100 grit from a soap maker supply place for about $6. I'll never run out of either of them.

My thoughts are only for hardened steel re: the diamonds cutting keener, for unhardened steel, anything works fine and cuts fast.

I don't subject diamond hones to flattening work now, either, though a spent one could have 100 grit loose diamond stuff sprinkled onto it.

[Aaron Rappaport]

OK, I remember now that I have a 3 carats or so of 100 micron diamond left that I got from Kingsley North. I guess I've wondered if they're cost effective. On the other hand, the SiC grit has been cutting tool steel slowly enough that I'm now definitely willing to shell out for something else that's faster!

[Johnny Kleso]

I use the loose grit to recharge my sand paper and think it works well..
You get 3-6x more uses out of it recharging ...

The loose grit can get messy as its like a black dust..
Diamond paste to me is OK but I feel its like a sin to use a diamond bench plate on steel.. For fine polishing I feel its not as bad as using one for coarse rough work..

Diamonds work on steel but its over kill IMHO..

I mean No One uses a diamond wheels to sharpen even the bevel, not even major blade makers...

On the other hand I think diamond grit would work very well on a leather lap which I plan on making for my MKIII

[Gary Curtis]

I have the powered Veritas Mark II sharpening device. It uses a flat platter with various grades of abrasive disks.

However, I found it hard told a plane iron dead flat when trying flatten the backs. So I went by a monument maker adjoining a cemetery here and their discards provided my choice of headstones made of granite or other stone.

All weighed nearly 70 or so pounds and serve as great sharpening stones. I've only tried carborundum in a slurry. Using diamond dust sounds like a smart idea to speed up the process.

[john brenton]

I bought one of those diamond stones from Home Depot a few years ago and was left with a flat,non-abrasive steel surface in less than a month. I think that using it to flatten the water stones is what killed it so fast.

I have another small DMT that I have used and abused to the max and it's just as good as when I got it. I'm really hoping that this 10" stone holds up. I'm really trying to be careful, but I think the hard times are over. After I received it I revisited all the chisels and irons that I had cheated on. It made quick work and I'm done with that....for now that is.



I am also in the category of people who killed a DMT only with hand pressure, and I didn't think I was pushing that hard. I liked how it worked when it was new. I guess I got a couple of sets of chisels and a couple of plane blades through mine before it pooped out. I will flatten anything that has enough metal left in the lamination or enough thickness left in a solid iron to be still useful after flattening. DMTs are not tolerant of that kind of behavior.

[David Weaver]

Diamonds work on steel but its over kill IMHO..

I mean No One uses a diamond wheels to sharpen even the bevel, not even major blade makers...

On the other hand I think diamond grit would work very well on a leather lap which I plan on making for my MKIII

I would imagine you're right, it's overkill and too expensive for manufacturers.

it's great for hobbyists, though, because it's not too expensive compared to all of the other things available to hobbyists.

I'll be interested to hear your assessment of diamonds on leather. I've stuck to green compound (almost don't care who makes it as long as it's western origin, even though it all is a little different level of fineness), because it cuts so fast for its fineness and I don't want to lose diamonds embedding deep in leather.

Diamonds cut extremely deep grooves, too, though at that level of fineness, I don't think it's worth worrying about. It's just enough worth thinking about if anyone wants to follow diamonds with another type of stone or abrasive (i.e., it doesn't make a lot of sense to go from diamonds to an oil stone because the oil stones cut flatter wider grooves, at least the natural ones do).

I had a discussion with a guy who sells natural stones a couple of years ago, and his term for what diamonds do to the edge after looking under magnification was "damage". he didn't like how drastically they cut, because he wanted to follow them with natural stones.

I don't use diamonds for anything other than initial flattening, and even then, only the really coarse sizes, like 100 grit. Even the very fine diamonds can raise a strong wire edge because they cut so drastically, at least in my experience, and they go everywhere and embed in everything, so I like to keep them away from fine stones and strops. The exception is that for HSS irons, I do use a diamond hone as a first step and then follow with a shapton stone. Most soak-free stones can't touch a diamond hone on HSS, so it's nice to get the geometry set up with a 1000 grit type diamond hone before moving on to something that really cuts HSS in a marginal way to begin with (I say most soak-free stones because I've tried most of them).

[Aaron Rappaport]

First, thanks to everyone for replying to my initial post!

On diamonds on wheels, I see that Woodcraft is now selling a diamond grinding wheel, which it says runs much cooler and lasts much longer than regular grinding wheels, (perhaps because it's metal?).

On diamonds on leather: Peter Tremblay, the "Chaplain of Woodnet" likes to use 0.5 micron diamond paste on the rough side of a strop.

[Mark Roderick]

I'm sorry, I wasn't clear.

The Kevlar sheets don't have diamonds imbedded in them. The Kevlar sheets just go on top of the granite (or other flat substrate) and protect it from abrasion. You'd sprinkle the loose diamonds on the kevlar and lap the blade flat, just as you propose. You could lean as hard as you wanted. I was just suggesting this method rather than using the loose diamonds on the bare steel cabana or whatever it's called.

I actually use this method to flatten my waterstones, using loose aluminum carbide.

[george wilson]

DO NOT use a rotating wheel coated with diamonds on steel. It is a well known fact in machinist's circles that if the wheel is rotating fast,the carbon from the diamonds will migrate into the steel,making it brittle.

If you are talking about a 200 RPM diamond wheel,like I have,it is o.k. to use the diamond wheel on steel. Fast diamond wheels are for grinding CARBIDE.

[george wilson]

I have the ultimate flattening machine,and I'd like to get rid of it. It is a 24" HORIZONTAL disc sander that was shop made by Virginia Metalcrafters. It is very nicely made with a very heavy 3 phase motor,and a heavy sanding disc. Around the edges is a good dust collection ring that has a 4" outlet. Has a good,heavy magnetic switch too.

It's sitting where I intend to put my old 20" Delta bandsaw when I ever get finished painting it. You would at least have to have a pickup truck and a strong helper to load it.

It would be ideal for flattening plane bottoms,or anything else. I'd put a frequency converter on it to make it go slow,or whatever speed I want to delicately introduce planes to it.