Next step after DMT EEF?

C

cm_bushman

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Oct 22, 2012
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I'm an avid Aligner user, and I've just expanded my stone set from XC up to EEF, and I'm liking the results so far. I'm able to get really nice polish on my edges, but I'm now looking for that true mirror-finish.

I was looking at the Dia-paste in 1 and 0.5 micron on a strop as the final stages, is this the way to go, or would you guys suggest something else for that level of polish? What are the best options for .25 and .1 micron pastes/sprays? Also, if I did go with the Dia-paste, would balsa or leather be a better choice of substrate? I'm practicing freehand on a carbon Mora, but I usually sharpen more wear-resistant steels like M4 and K390 on the Aligner, which is why I was leaning toward diamond paste. I'm not good enough at free-handing to go full-on with a $100-200 waterstone.
 
IME for a mirror and won't round and or wire the edge. try 3, 1, 0.5um diamond paste with the angle 2 degree lower than sharpening angle. Then 0.25um at sharpening angle - a crucial step for polishing & sharpening. Then 0.1um at angle as 3um. Printer paper over glass or aluminum backing would work. Balsa & leather are too soft for polishing.
 
I'll echo bluntcut's suggestion to use the sequence of Dia-Pastes. In particular, the 3µ Dia-Paste really blows the door open on the polish, especially if used on a harder strop, such as wood. I use it on basswood, which is firmer than balsa, but still embeds the compound very well. It works fast, and really brings up a mirror that's obvious to the naked eye. Using 1µ and finer pastes afterward can only improve on that.

(I'm also gravitating away from using balsa, which has started to feel too soft for my preference.)


David
 
I made a steel blank the same size as the stones and stick 3000 grit diamond tape to it.
 
For more abrasion resistant steels, I use diamond films or either CBN or diamond, preferably polycrystalline. The quality of both the diamonds in a product and the formulation the diamonds are in makes a difference as does the substrate you put the product on. For diamond films I prefer a glass backing. For compounds I prefer a thin leather with a hard backing for a more precise edge. I don't find the EEF plate to be as fine as the equivalent 8k stone, but more like a 5k level of finish. A 3 micron film is ~ 6k, so that or a 2 micron (8k) would be a good starting point past the EEF plate.

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Ken
 
Well, the EEF is billed as 3 micron, so you think the 3 micron spray/paste would improve the polish? I think I'm going to go down to 1 micron as the finest I will ever need (until I need 0.5, and then 0.25...), that (according to the Grand Unified Grit Chart) is on par with an 8k which seems to be the standard for high-polish in kitchen knife circles.

So, is diapaste the way to go, or do you guys prefer the Hand American sprays? I've heard nothing but good things about those. Are they considered superior?
 
The DMT EEF is 8000 Mesh not grit. It's a different rating and is not comparable to Japanese waterstones, sandpaper, or oil stones. The inherent nature of the diamonds makes the edge extremely toothy for the given grit and the diamond abrasive itself is so hard it's not rubbing, polishing, or burnishing but Purely cutting.

The diamond is sharp and very hard so the track left by the diamond is naturally polished. If you get a nice clean edge with a diamond plate you can sometimes see a rainbow reflection of light in the scratch pattern itself, the scratches are too coarse to show true reflections but you can see the refraction of light in the grind pattern.

When I mirror polished edges with my DMT plates I would use the 6 micron DMT paste AFTER the EEF, it becomes a substrate issue at this point because you switch from a hard plate to a soft leather or wood which gives the abrasive cushion. Using a firm board as David mentioned gives a better cutting action to the compound but even with the 6 micron paste it would take a minute to polish out the 3 micron diamond plate scratches.
 
6 micron lapping film makes a brighter finish than the DMT EEF. I much prefer lapping films for the finer diamond polish over compounds/pastes but is a personal preference. I don't deal with a lot of high VC steel, so a few sheets of 6" lapping film at under $6 a sheet make a lot of sense for me. I use them with a drop of mineral oil, they appear to hold up extremely well when used with a light touch.
 
HeavyHanded said:
6 micron lapping film makes a brighter finish than the DMT EEF. I much prefer lapping films for the finer diamond polish over compounds/pastes but is a personal preference. I don't deal with a lot of high VC steel, so a few sheets of 6" lapping film at under $6 a sheet make a lot of sense for me. I use them with a drop of mineral oil, they appear to hold up extremely well when used with a light touch.
Click to expand...

That's half the reason I stopped using compounds so much, all that stropping at relative coarse grits was a PITA. The films would be a much better choice.
 
Okay guys, this is all news to me, it looks like I will have to look further into films! I always worry that the film will tear and wear out quickly, like sandpaper. Is this the case, or do the films last longer on average with the harder, smaller abrasive? This is the main reason I was leaning toward paste, since it would ostensibly last much longer per dollar.

Also, is there a consensus on CBN vs. Diamond? I've not heard a lot about CBN in general, or how it differs in use from diamond, only that some prefer it.

Are there specific sheets that you guys would recommend as good quality?
 
"Well, the EEF is billed as 3 micron, so you think the 3 micron spray/paste would improve the polish? " Well yes it will - depending on the spray or paste. Not all 3 micron pastes or sprays are the same - or films for that matter.

Look at some of these postings to get some more background on the subject:

http://precisesharpening.blogspot.com/

I've found the films and compounds give a more uniform finish than the EEF fine plate - seems like it's just a more uniform particle size.

There are various films that I carry along with CBN and (mono and poly) diamond sprays, emulsions and pastes. I use diamond films, however the cheaper aluminum oxide and SIC and CRO films are also available.

There are advantages and disadvantages to each approach. Send me a PM if you want a detailed discussion of the differences between each of these approaches. I could write a book on the topic.


Jason, yes mesh and grit are slightly different scales and used [erroneously] interchangeably - even when discussing Japanese waterstones. Look at a Shapton Glassstone - they use MESH ratiings. Surprised?

If you want to be a bit more precise think in terms of microns. There are various conversion tables available to convert between the confusing array of measuring 'standards' out there. Even after you get through this you get into the purity of the sample, etc etc (read the referenced blog and look for psd data on some samples for more detailed understanding of what I'm referencing.)

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Ken
 
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