Soft Steels and DMT Diamond Paste?

AFAustin

AFAustin

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From my reading here, it is my understanding that diamond stones are unnecessary, and even detrimental, when sharpening simple carbon and softer stainless steels. Would that also apply to 1 micron DMT diamond paste applied to a leather strop?

Would the answer change if it were the same DMT 1 micron paste applied to a leather belt for a grinder or Work Sharp?

Thanks for any info. and opinions.

Andrew
 
AFAustin said:
From my reading here, it is my understanding that diamond stones are unnecessary, and even detrimental, when sharpening simple carbon and softer stainless steels. Would that also apply to 1 micron DMT diamond paste applied to a leather strop?

Would the answer change if it were the same DMT 1 micron paste applied to a leather belt for a grinder or Work Sharp?

Thanks for any info. and opinions.

Andrew
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This is timely. :)

Just so happens, today I've been experimenting with a paper-on-plywood strop, using some 3-micron DMT Dia-Paste. I'd used the 1-micron in the past quite a bit, and wanted to get more acquainted with the capabilities of the 3-micron stuff on the paper. I stropped 3 knives: a Kershaw Leek in S30V, a sheepsfoot blade on a Queen stockman in D2, and the 420HC sheepsfoot (convexed) on my Buck 301 stockman. Worked great on all three, polishing very quickly and leaving nicely-shaving edges on each (with some supplemental bare-leather stropping on a belt, afterwards). My main objective was to test the paper strop itself with diamond. After seeing how it worked out, I'd highly encourage using a very firm backing with the diamond compound, as it'll be very, very quick to round off a soft-steel edge on a softer substrate. I've noticed that before, in using 1-micron diamond and other aggressive compounds, like SiC, on softish backing; the bigger danger is in the conformability of the substrate, more so than the aggressiveness of the compound itself. On softish or more conformable backing, it's very easy to over-polish and round off steels that aren't wear-resistant (like 420HC), while more high-wear steels (D2, S30V) are more tolerant and forgiving with aggressive compounds on similar backing. So long as the backing is very firm, the main difference noticed will be in the speed at which the compound does it's work.


David
 
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David,

Thanks for your post. Sounds like, as far as the softer steels, the diamond paste on a typical leather strop or leather grinder belt is apt to do more harm than good.

Andrew
 
AFAustin said:
David,

Thanks for your post. Sounds like, as far as the softer steels, the diamond paste on a typical leather strop or leather grinder belt is apt to do more harm than good.

Andrew
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At the very least, I'd say keep pressure as feather-light as you can, if using a softer backing with aggressive compounds on softish steels. After making my earlier post, I broke out my beloved Schrade 8OT stockman (1095 steel) to test on the strop I mentioned. I'm hesitant to use diamond at all, on 1095, except for setting bevels; it's very fast in that capacity, even using a small credit card hone. But if used with care, and minimally (few passes), diamond paste can work as well as anything. Even at small/tiny grit sizes like these diamond pastes, it's not hard to remove way too much steel at the edge, very quickly, on blades like these. 1095 goes perfectly with AlOx and/or green compound, so far as I'm concerned, followed by bare leather. I've yet to produce a better edge on any blade, than I've been able to do with that combination.

Having said all that, a firmly-backed strop, like paper-over-wood (or glass, stone, etc) will still work very, very fast on these steels. The bonus is, the firm backing helps to ensure the edge produced will remain crisp, and bevels will polish up very fast. That's what I'm really liking so far, in testing this particular strop & compound combo.


David
 
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Diamond stones and/or paste are not needed on softer steels.

But they can be used to excellent effect if you're careful and have a very light touch.

I've used a DMT XXC to reprofile an old 1095 blade. A light touch, and attention to detail, and an excellent job was done in minutes.

A water stone would have worked just as well, but the DMT was mounted and adjusted on the EP, so I used it.

A careful sharpener has no problems with too much stone. The problems come with too little.
 
My personal experience is that the diamond on common steels is no different and perhaps not as nice as alumox or SiC. More to effectiveness at this level, the shape of the abrasive and what's being asked of it maybe more important than hardness. As David has advocated and I agree entirely, the firmer strop works more consistently with fewer issues and greater margin of error, and other abrasives are cheaper to toss when they load up. On a leather belt it might be a different issue - more surface area will equal less loading and longer life maybe. Still and all, if the steel doesn't call for it there are better options. Even if the steel does call for it, my belief is you're better off with diamond lapping films over diamond paste.

Martin
 
Thanks, gents, for your informed replies.

My exact situation is that I regularly use a Work Sharp KO to do my initial sharpening. On the softer steels, I have wondered whether to stop on the finest "regular" belt I have, a Micro Mesh 6000, which I would guess is 2-3 micron as it is very worn: http://micro-surface.com/index.php?main_page=page&id=16 or my leather belt with 1 micron DMT diamond paste.

Although the leather + DMT paste belt would seem to provide a finer micron finish, from what you all have said, I'd probably be better off stopping with the worn Micro Mesh 6000.

Thanks for your advice.

Andrew
 
Is 52100 at >60 HRC considered soft or hard ? :p

On the other hand, I'm also thinking to use Diamond paste on paper to bring back ceramic edge. The finest diamond plate I have is EEF, I guess 3u. Will paste + slightly softer thick paper work better than plate (4x1 dotted) on ceramic?
 
Chris "Anagarika";13341621 said:
Is 52100 at >60 HRC considered soft or hard ? :p

On the other hand, I'm also thinking to use Diamond paste on paper to bring back ceramic edge. The finest diamond plate I have is EEF, I guess 3u. Will paste + slightly softer thick paper work better than plate (4x1 dotted) on ceramic?
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I'd say 'hard', but I think the term is somewhat less meaningful than 'wear-resistant', which would better apply in this context. No significant carbide content in 52100 steel, if any at all. The Schrade 8OT's 1095, which I mentioned earlier, is said to have been hardened to ~60 HRC. Beautiful edge-holding, but aggressive abrasives will still eat it for breakfast, due to the complete lack of ultra-hard carbides in it. This is why I've generally avoided using diamond or even SiC on it, as I view USA Schrade's 1095 as a rare and precious commodity. Hate to waste it. ;)

Regarding using the paste on ceramic, I haven't tried using it this way (don't currently have any ceramic blades). But I don't see any harm in trying it out; that's the best way to know. If I did, I'd be trying it on paper, wood or even on glass, or any combination thereof, like paper-on-glass. Still, I wouldn't go too thick or soft with the paper. Thicker card-stock paper could still be pretty firm, and likely more durable as well.


David
 
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AFAustin said:
Thanks, gents, for your informed replies.

My exact situation is that I regularly use a Work Sharp KO to do my initial sharpening. On the softer steels, I have wondered whether to stop on the finest "regular" belt I have, a Micro Mesh 6000, which I would guess is 2-3 micron as it is very worn: http://micro-surface.com/index.php?main_page=page&id=16 or my leather belt with 1 micron DMT diamond paste.

Although the leather + DMT paste belt would seem to provide a finer micron finish, from what you all have said, I'd probably be better off stopping with the worn Micro Mesh 6000.

Thanks for your advice.

Andrew
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I overlooked this when it was posted earlier. One thing that's occurred to me, in using the diamond paste over something less aggressive, is that it's very handy & very quick for polishing up softer steels that still have some relatively coarse scratches in the finish. I'm noticing this on the Buck stockman in 420HC. If I were attempting to polish with AlOx or similar less-aggressive compounds, I'd be better off in first refining the scratch pattern with an intermediate grit. With the diamond compound, especially if used on wood or similar firm backing, it still quickly zips right through the coarse scratches on softer steels like this, with little need for a go-between grit. Really a testament to the difference in working speed, as compared to lesser compounds. Sort of a 'lazy sharpener's shortcut' to a high polish, if you will. ;)

Used on a powered belt, it shouldn't matter much anyway. The polishing speed advantage of diamond over other compounds is most easily seen when polishing by hand alone. On a powered tool, I'd keep a very close eye on how much progress is being made; I'd suspect things will happen very, very fast.


David
 
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