Diamond plates

[Kees Heiden]

What's the difference between an iwood 300 and an Atoma 400? Appart from the obvious grit difference of course. And apart from the price.

I am looking for a replacement for my DMT coars/xcoarse. It's quite dead now. I used the xcoarse side to flatten my waterstones. But I think my Bester 400 and an India medium have kind of killed this side. The coarse side is still pretty good, I used it to flatten a jointer plane blade last week, but it is not very usefull for stone flattening because it because of the extreme stickion.

So I am looking for something to flatten waterstones. And something for flattenig backs of antique, pitted chisels and planeblades. And I am NOT happy with the sandpaper on glass method. Maybe I'll also aquire a Sigma 400, but I'll definitely need something flat and coarse for the initial metal removal.

[les winter]

Hi Kees.
I use the dmt extra extra course 3x8 for flattening water stones and Arkansas stones. For this purpose it works great.
In my experience, limited to dmt products, using diamond stones to flatten chisel and plane iron backs wastes the stone.

I see that you don't like sandpaper.

A hybrid approach works for me. I use self stick 3m gold (80 grit) to do the major metal removal on old tools. I stick it to a small granite plate. From there I go to either an India stone or my water stones. The water stones get a few flattening strokes from the diamond plate after 10 or 20 strokes of the tool back.
In this way, I save my water stones and diamond plate for what they are best at, and use the 3m Gold for what it does best. This is the fastest way I know of to accomplish flattening of old tools.
The extra extra coarse plate does not work well on tool backs, by the way. At least in my shop.
Best of luck.
Les

[David Weaver]

Loose diamonds on steel or cast iron to remove any significant amount of steel off the back of an iron. And make a holder with handles to hold the iron so that you can put your full body weight on the effort and not have the pressure focused on your fingers. 100 grit diamonds and something thin (like WD40 or something similar) makes a nice combination. They are about $0.25 per carat here in the states. 50 carats will last you until you decide that you've lost interest in restoring old irons and chisels.

The other option is PSA stick down rolls on a long run of glass. A short piece of glass and a full sheet of paper sandpaper is a pain in the butt. Even the PSA stick down can be a pain in the butt (due to having to change it) if you really have to remove a lot, but it's fast.

In terms of the diamond plates, the atomas are flatter in general. They also are probably more durable than any other electroplate diamond hone maybe short of the expensive flattening plate DMT makes. Instead of having their diamonds on the surface in an arrangement that looks like someone sprinkled diamonds on and then spray painted over them, they are little clumps of diamonds with space between the clumps. In my experience, the atoma plates get duller feeling and then pretty much stay at that level and don't get burnt out in the middle of the plate as fast as DMT. None of them are remotely close to loose diamonds, though - you can use unlimited pressure on loose diamonds and sprinkly a fresh layer on any time you want.

I think for coarse stones and india stones, it's probably better to flatten on loose silicon carbide, though. Every diamond hone I've used gets burnt out by the coarse stones and ends up too fine, and then all it seems to do is grade the abrasive on the coarse stone, making it cut more finely - totally undesirable.

[Chris Griggs]

Hi Kees. I have both. Both work very well for flattening waterstones. They have a slightly different feel on the stones. The iWood hs more of the coarse diamond feel and the Atoma has a finer more grating feel, but they work equally well. However, I wore out my iWood after a couple years and replaced it with the atoma. This was my fault as I used it on coarser stones than I should have (though not a lot). I'm more careful with the my atoma and really only use it on 800 and above, but do have the impression that it is a more robust diamond plating and like Dave said, I've heard that they are more consistently flat. Again, either work fine for flattening, but my impression is that the Atoma's extra costs gives you tighter tolerances and more durability, so I think its worth it.

[les winter]

Hi David.
The DMT is purpose made for flattening stone. Chris Schwarz has written about its durability for this duty and found it pretty good. My experience, using 3x8, is similar.

[Kees Heiden]

I have been thinking about loose diamond grit. Almost ordered it, but I don't know yet where to find a flat steel plate. Somehow the concept of the Kanaban hasn't taken hold overhere yet. I do know a place where I can get O1 steel, maybe a polished plate of O1 steel comes flat?

Sandpaper always seems to loose its oomph in very short order. I tried all kinds, but no luck. And somehow the shape of the lapped iron after the sandpaper never is the same as the shape the waterstones want to make. PSA stick down rolls are not available overhere, so I have to use spray glue, which is a royal pain. All reasons not to continue with sandpaper.

[David Weaver]

Hi David.
The DMT is purpose made for flattening stone. Chris Schwarz has written about its durability for this duty and found it pretty good. My experience, using 3x8, is similar.

I don't know whether or not someone has burned out a diaflat. I personally can't tolerate the idea of a $175 flattening plate (I bought one and sent it to stu, so I got a good look at it before it went overseas). I've burnt out three other DMTs, though - both duoflat types and the elevated bench stone type.

If one can manage to use a diamond hone only for 1000 grit waterstones and above, any of them will last quite a while. However, the DMTs respond especially poorly if you use them for both flattening tools (in any quantity) and flattening stones, or especially if you use them to flatten india stones at all. I haven't used them with coarse waterstones, I knew those were bad for them already.

The trouble with the diaflat, along with the price, is that if someone uses oilstones and waterstones, they will likely want to use two different diaflats - a princely $um, and the diaflat is entirely unsuitable for harder natural oilstones, and in my opinion, unsuitable for hard fine waterstones, too - it's too coarse.

The atoma 400 for medium and fine waterstones and some loose silicon carbide grit for medium or coarser oilstones seems to be optimal from a price and function perspective. Silicon carbide can be had for about $10 for 2 pounds, and purchase of some 60/90 and 220 grit (two separate types) ends up being useful sooner or later in the shop.

Stu carries the atoma for about $70 or so.

That leaves fine oilstones out in my equation, but after they are initially flattened, I don't like to touch them - they cut infinitely coarser when they have deep scratches in them from a diamond plate - their bond is strong enough to make scratches behave like large grit.

[David Weaver]

I have been thinking about loose diamond grit. Almost ordered it, but I don't know yet where to find a flat steel plate. Somehow the concept of the Kanaban hasn't taken hold overhere yet. I do know a place where I can get O1 steel, maybe a polished plate of O1 steel comes flat?

Sandpaper always seems to loose its oomph in very short order. I tried all kinds, but no luck. And somehow the shape of the lapped iron after the sandpaper never is the same as the shape the waterstones want to make. PSA stick down rolls are not available overhere, so I have to use spray glue, which is a royal pain. All reasons not to continue with sandpaper.

In my opinion, you don't want O1, you want mild steel. It's cheaper and better for it. The little kanaban that harima tool must distribute to ever woodworking supplier in the world is fine, despite the fact that it isn't always perfectly flat. In my experience, you want something narrower like it - it'll be a lot easier to keep flat (everything eventually goes out of flat). Lapping mild steel is problematic. Cast, like the sole of a #5 that has been flattened and placed in a holder of some sort is also suitable.

With a holder, this type of setup can grind a fairly badly pitted iron (that you would otherwise not recover) in about 45 minutes. Irons that are not as badly pitted and that take 45 minutes by hand will take about 5 minutes on this setup (and be ready for a decent medium india or a 1000 grit waterstone when you're done), and your soreness will be in your triceps instead of fingers (and you won't wear skin off of your fingers).

[Kees Heiden]

What size of diamond grit do you use? The coarsest available everywhere seems to be 45 micrometer. With a bit of searching I can find 50 to 60 micrometer in China.

[David Weaver]

I used a bag labeled 100 grit. 100/120 mesh.

The bag says it's 125/150 microns or something.

You can find it on ebay

271221256047

No affiliation, of course. I bought most of my diamonds from a seller whose name is "yuri malnev" on ebay. If you search the US ebay for "loose diamond grit", you'll see his stuff. I can't vouch for anyone else, but if they list micron size, you're pretty safe.

I wouldn't go any finer than 100 grit, personally. It seems to be ideal for the task of anything that is too out of whack to be done up on a 1000 grit waterstone, and it's fast.

[Kees Heiden]

Thanks, I'll check him out.

[Kees Heiden]

The grit is on its way to The Netherlands, as we speak. :D
And it looks like I found a very flat clump of mild steel. I'll bring some feeler gauges tomorrow to check it further.

So that leaves me to order just an Atoma 400 for flattening my waterstones.

[george wilson]

Cast iron would be better yet.

[Kees Heiden]

Probably but I don't have any.

[Frederick Skelly]

David -
Im going to try your suggestion on loose abrasives. Do I need to take any safety measures to protect against inhaling fine grit? (I normally wear a good mask when sharpening, based on a safety recommendation I read early on. It may be overkill, but its easy to be conservative.)

Thanks,
Fred

[David Weaver]

No, the diamonds are fairly coarse and dense. They won't break into fine dust like a silicon type abrasives would. You'll want to use a very thin oil or water displacer (WD 40 or whatever) with them, and the whole bunch of swarf and diamonds will turn into one big greasy glom on the surface of the steel (that you can mitigate either by adding more WD 40 or by wiping all of it off).

I don't know if there's any danger to breathing in carbon and iron or diamonds, anyway. Silica dust isn't part of the equation, fortunately. At any rate, there won't be any dust.

Long ago, I put a picture of a very nasty ugly iron holder up on here - it's an essential part of the process. I'll track down the post.

http://www.sawmillcreek.org/showthread.php?160656-Free-(to-make)-Iron-Holder-I-know-I-ve-posted-this-before

(it is fantastic to be able to put all of your body weight into lapping something without having sore fingers, or shapton finger syndrome ("SFS"). I'd define SFS as suddenly finding blood on your medium grit stone, having no clue where it came from, and finding that the fingers you had on the iron have had skin honed off by the medium stone - it's like cutting yourself with a sharp knife in that you don't even feel it).

[Steve Voigt]

Long ago, I put a picture of a very nasty ugly iron holder up on here - it's an essential part of the process. I'll track down the post.

http://www.sawmillcreek.org/showthread.php?160656-Free-(to-make)-Iron-Holder-I-know-I-ve-posted-this-before

(it is fantastic to be able to put all of your body weight into lapping something without having sore fingers, or shapton finger syndrome ("SFS"). I'd define SFS as suddenly finding blood on your medium grit stone, having no clue where it came from, and finding that the fingers you had on the iron have had skin honed off by the medium stone - it's like cutting yourself with a sharp knife in that you don't even feel it).

As a long-time sufferer from SFS (hey, why is this plane iron red?), I'll second the recommendation for using a holder. It really speeds up the flattening if, as Dave says, you can put your weight on what you're trying to flatten.
On Derek Cohen's site, I came across a pic of him using a mag base (http://www.inthewoodshop.com/WoodworkTechniques/Lapping%20the%20Backs%20of%20Blades.html) as a blade holder. After I slapped myself a couple times for not having thought of that, I went downstairs and tried it--it works great. If you happen to have one of these lying around, it's worth a try. One tiny modification I would suggest is to unscrew that long steel shaft so that the mag base is easier to hold.

[Kees Heiden]

Yes that hurts after a while, and it heals rather slowly.

I use something like your holder too. Mine doesn't have these handles, just a length of wood with two bolts. I want to put an old Stanley frontknob above the edge to make it even better.

[David Weaver]

Medium CA glue is a decent remedy for SFS.

[Jonas Baker]

The trouble with the diaflat, along with the price, is that if someone uses oilstones and waterstones, they will likely want to use two different diaflats - a princely $um, and the diaflat is entirely unsuitable for harder natural oilstones, and in my opinion, unsuitable for hard fine waterstones, too - it's too coarse.


I use my DMT Dia-sharp diamond stones for flattening both oilstones and waterstones, and it is not a problem to go back and forth. The oil washes right off the dmt stone so it does not contaminate the waterstones afterward.

I wore down my original DMT coarse stone pretty well though it does work, just slower, and it seems to have a finer grit to it now. I don't think flattening stones was what did it (though I never used it much on grits lower than my 700 Sigma carbon stone), but flattening chisels and plane irons is what really seems to wear through them. Actually what really wore through my coarse stone was when I tried flattening a block plane on it (so stupid). As you said, there are better way to flatten plane irons and chisels. I now only use my diamond stones for flattening water and oilstones. My extra extra coarse (which is too coarse for flattening fine oilstones or waterstones in my opionion), has almost all of it's grit left after a lot of use.


That leaves fine oilstones out in my equation, but after they are initially flattened, I don't like to touch them - they cut infinitely coarser when they have deep scratches in them from a diamond plate - their bond is strong enough to make scratches behave like large grit.

I also have to say, when I flatten fine oilstones I only use my worn down coarse stone (which takes a long time for hard stones like arkansas). This makes the stones behave much finer than when I'm using a coarse diamond stone to flatten them. When I use my extra extra coarse DMT stone it makes a fine oil stone behave like a much coarser stone.

[Frederick Skelly]

Thanks David. That helps. Yes, I built one of your holders a few months ago after you posted a pic for me. It made a HUGE difference - my sharpening improved noticeably - I could finally get the backs (properly) flat and I no longer needed the ruler trick. And it did indeed cure my SFS! So thanks again for your help.

Steve, FWIW, I also tried the magnets and they work well too. I cant use them on my DMTs, but they work well when Im on sandpaper.

Fred

[Kees Heiden]

Stu is on hollidays in Australia at the moment, so I have plenty of time to read up, before I start ordering. What I have now:

A very flat chunk of steel, comes from an old sheet metal brake. It's 25 cm long and I can't get a 0.05mm feeler gauge between it and an expensive straight edge.
100 grit diamonds are somewhere sailing towards me now. I hope they arrive this month.
80 grit SiC grit has been ordered locally, and I still have a bunch of granite tiles. That should help flattening coarse stones.

In my shopping basket for Tfj is now a Sigma 400, a Cerax 320 and an Atoma 400 to keep my other stones flat. The Sigma stays very flat they say but doesn't cut very quickly and the Cerax is the other way around. Seems like a good combo, especially at that price.

Would I be properly prepared for my next batch of ugly, rusted, antique rubish?

My last pile of crap cost me 30 euro and contained two wooden jointers, a boxwood compass plane, and a set of 3 rounds that look like 18thc century ones in all respects, but have no planmakers marks, so I can't prove it. All planes need major work of course.

[David Weaver]

You're about as ready as you're going to be. The only way to work much faster than that is to get an accurate belt sander with high tension on the belt and run it at low speed - that's something mere mortals aren't going to do.

The grinder, 100 grit diamonds and then straight to a decent 1000 grit stone has always done it for me. the sub 1000 grit stones are nice to use if you're going to forego grinding, but I've not used them for anything else. It is a contest, though, to keep the hard ones cutting like a coarse stone - you could always keep the 400 grit awake by sprinkling a few pinches of silicon carbide on the surface. it'll break down (and not contaminate the stone) and break out fresh abrasive, though of course, the virtues of supreme flatness won't be quite as apparent if you do a lot of that - you can always flatten the stone.

I've always found a 400 grit diamond hone to refresh the chosera 400 somewhat, but it also grades it up a notch in fineness a little bit.

Anyway, the iron holder that you already have is the key to near utopia with making fast work of pitted irons.

[Kees Heiden]

Near utopia, that's what I need. :)

[Wout Moerman]

try to find an cast iron poffertjespan with a flat bottom. It might do the trick.

Wout

[Kees Heiden]

That's also a good idea. There should be plenty around. Probably not very flat though.