Longer-lasting Sharpness?

[Luke Dupont]

My usual method for sharpening is to finish off on a medium-ish stone, and then strop to achieve a razor-sharp edge.

I've changed my method quite a few times, from waterstones to sandpaper to diamond stones, and now, finally, to an India stone sometimes followed by a soft Arkansas prior to stropping.

With all of these methods, I do get a very sharp edge, but I find the sharpness I get from the strop to be very transient. It disappears very quickly with the slightest of use.

So, I am wondering, how fine is it necessary to go, and would I retain a higher level of sharpness for longer if I bridged the gap between my low/medium grit finish stones, and the strop, or would the added sharpness also just be a very transient thing?

I suppose it could be the angle that I'm sharpening at, too. I tend to sharpen with a very slightly convex bevel, from about 25 degrees to a little under 30 degrees or so at the very edge.

The level of sharpness that I get currently is plenty good for my purposes, generally, but I'm just curious what is really necessary and how I might improve my process. For example, if what I get from stropping disappears so quickly, is it really necessary to strop? Might I get better results just from, say, an India and a hard or translucent/black Arkansas, leaving me with just two steps in the process? Would the level of sharpness that I get from ending on either of those two stones last longer than the level of sharpness that I get from my current progression of India > Soft Ark(sometimes) > Strop? And would changing my angle to a few degrees steeper make any noticeable difference in edge retention?

I've been playing with some small Arkansas stones for a while now and have been enjoying them, but I finally just ordered a 2x6" combination Soft/Hard Arkansas from Dan's, so I think I'll do a bit of playing around to see if what kind of edge I get from the Hard Arkansas, and whether or not the Soft is something I like using as a precursor, or if I prefer to stick to the fine India. I'm also curious if I might benefit from a translucent Arkansas as a finish, in which case perhaps my sharpening routine could consist of India or Soft -> Translucent, with or without the hard ark as a transition.

In other words, I'm interested in finding where I want to be on the triangle of trade-offs between the number of steps involved in the process of sharpening, the level of sharpness attained, and how long that level of sharpness is retained. I'm also curious just how important having more middle-steps is (ie, do they just contribute to the end level of sharpness, or do they help to retain a higher level of sharpness as the blade wears?)

Also, though a bit off-topic: I'm finding I'm really enjoying Arkansas stones, and especially the India that I picked up. I think I may have finally settled on oil-stones. I'd been using diamonds, and I just don't like the feel of them and couldn't find a lubricant that worked well for them. The India, in comparison, is quicker for roughwork on the coarse side, and feels much nicer on the fine side, while still leaving a good edge for its grit. The Arkansas stones are more slick and much slower, but I like the feel of them and the edge that I get even from the coarser ones. I'm curious to see if I'll like a hard or translucent.

[Stanley Covington]

Once you are capable of sharpening a blade up to certain level of consistent sharpness, regardless of the methods and tools used to develop that edge, the longevity of that sharpness depends on the quality of the steel, all else equal. In the final analysis, it is the molecular structure of the steel itself that must stand or fade away.

[Patrick Chase]

Once you are capable of sharpening a blade up to certain level of consistent sharpness, regardless of the methods and tools used to develop that edge, the longevity of that sharpness depends on the quality of the steel, all else equal. In the final analysis, it is the molecular structure of the steel itself that must stand or fade away.

Must....resist....the....bait.

OK, so that didn't work. It's more the crystalline/grain structure than the molecular structure that may be an issue for sharpening. Steels with pronounced grain structures like A2 are more difficult to uniformly sharpen (uniform == without chips, voids, or similar discontinuities), so "capability" itself is very much a function of the steel. Somebody can be perfectly capable of getting a great edge on HCS, but they might be utterly hopeless on A2. I therefore think that you have to take a more holistic and iterative view as opposed to "first get 'good' at sharpening, then pick a steel, any steel".

[Stanley Covington]

Must....resist....the....bait.

OK, so that didn't work. It's more the crystalline/grain structure than the molecular structure that may be an issue for sharpening. Steels with pronounced grain structures like A2 are more difficult to uniformly sharpen (uniform == without chips, voids, or similar discontinuities), so "capability" itself is very much a function of the steel. Somebody can be perfectly capable of getting a great edge on HCS, but they might be utterly hopeless on A2. I therefore think that you have to take a more holistic and iterative view as opposed to "first get 'good' at sharpening, then pick a steel, any steel".

Ha ha, hee hee! He took the bait! 😈

Molecular structure may not have been the most precise term, but it is still 90% of the equation, without which the crystalline lattice , which you correctly identified, never forms.

I think we can agree on the virtues and shortcomings of A2, but sharp is sharp. Even copper can be made very sharp indeed. So to reiterate my point, if one can create a sharp edge, all else equal, the nature of the steel will govern edge retention. I think this is obvious, but see people spend years developing skills on blades that are far less than ideal, when perhaps they would be better served with better blades.

[Warren Mickley]

It is not unusual for an experienced craftsman to get better edge longevity than a beginner or amateur using the same materials. Sometimes remarkably better results. Sometimes it is kind of shocking how easily a novice can degrade an edge. That is because subtle differences in sharpening technique and tool usage technique do have affects. The ideal is for a beginner to work alongside a craftsman, each observing the other.

You mentioned use of finer polishing stones and the use of intermediate grits. Discernment plays a big role here. Your ability to discern the difference between one sharpening schedule and another, or the difference between spending more time on a certain stone or not, is the best guide.

When you are starting out in sharpening, you are following someone else's recipe. You hear guys arguing about which is the best recipe, but execution is just as important as specific tools, specific stones, or specific schedule. If you cook a dish often enough you gradually learn how each ingredient and each step affects the outcome. This is the kind of thing you want to look to learn about sharpening and tool usage. The more alert you are and the more you can notice, the faster you will learn.

[Patrick Chase]

Ha ha, hee hee! He took the bait! 

Molecular structure may not have been the most precise term, but it is still 90% of the equation, without which the crystalline lattice , which you correctly identified, never forms.

I think we can agree on the virtues and shortcomings of A2, but sharp is sharp. Even copper can be made very sharp indeed. So to reiterate my point, if one can create a sharp edge, all else equal, the nature of the steel will govern edge retention. I think this is obvious, but see people spend years developing skills on blades that are far less than ideal, when perhaps they would be better served with better blades.

OK, let's take a more extreme example: Derek's (first) chisel steel comparison.

I think we can all agree that Derek is very experienced and capable of getting a sharp edge on typical tool steels. With that said, if you read that review one thing that is obvious is that he didn't have the right technique or materials to put a good edge on CPM-10V. I'm quite certain that if he were forced to use nothing but CPM-10V chisels he'd iterate and experiment until he figured it out, and his results would be very different than in that comparison.

That's (partly) what I meant by "holistic and iterative view".

[Stanley Covington]

OK, let's take a more extreme example: Derek's (first) chisel steel comparison.

I think we can all agree that Derek is very experienced and capable of getting a sharp edge on typical tool steels. With that said, if you read that review one thing that is obvious is that he didn't have the right technique or materials to put a good edge on CPM-10V. I'm quite certain that if he were forced to use nothing but CPM-10V chisels he'd iterate and experiment until he figured it out, and his results would be very different than in that comparison.

That's (partly) what I meant by "holistic and iterative view".

Your point is still unclear, and your rebuttal fails to engage.

[Tim Cooper Louisiana]

Your point is still unclear, but amazingly appears to continue to fail to engage.

I know it comes from a good place, but be prepared to argue your thesis if you post anything here.

[Stanley Covington]

I know it comes from a good place, but be prepared to argue your thesis if you post anything here.

There is a consistent problem on this forum of weak reading comprehension. There is no medicinal cure for this ailment.

My point ("thesis," if you prefer to exaggerate our little posts) was clearly made. I will not argue a point or thesis I did not present, nor will I respond to thoughtless words that might offend Derek.

[Warren Mickley]

OK, let's take a more extreme example: Derek's (first) chisel steel comparison.

I think we can all agree that Derek is very experienced and capable of getting a sharp edge on typical tool steels. With that said, if you read that review one thing that is obvious is that he didn't have the right technique or materials to put a good edge on CPM-10V. I'm quite certain that if he were forced to use nothing but CPM-10V chisels he'd iterate and experiment until he figured it out, and his results would be very different than in that comparison.

That's (partly) what I meant by "holistic and iterative view".

Five years ago I repeated Derek's edge test with five chisels of my own, chisels from 1828 to 2008. All did better than Derek's tests. I am inclined to think that at least some of the difference can be ascribed to such things as sharpening media, sharpening technique, and technique in using the chisel. I believe all of these are rather different from Derek's practice. And experience is important. I have used the same techniques for more than four decades.

[Prashun Patel]

Lots of more experienced guys than I here, but I vouch for warrens statement about experience and practice playing a big role.

I believe you will get the biggest bang for your buck by simply practicing sharpening and planing more. Optimize using your current method before switching or tweaking it.

[glenn bradley]

Must....resist....the....bait.

Ha ha, hee hee! He took the bait!

Ahhhh, hand tool sharpening discussions .

[Derek Cohen]

Five years ago I repeated Derek's edge test with five chisels of my own, chisels from 1828 to 2008. All did better than Derek's tests. I am inclined to think that at least some of the difference can be ascribed to such things as sharpening media, sharpening technique, and technique in using the chisel. I believe all of these are rather different from Derek's practice. And experience is important. I have used the same techniques for more than four decades.

Warren, you miss the point. No doubt you do use a chisel differently from me. I have no idea how you use a chisel since I have never seen anything you have made, or of photos of you handling a chisel. For all I know you are the best in the world. That would still be beside the point.

The point is that the article was a comparison of steels. To compare steels one subjects them to the same conditions. Regardless of technique, as long as the conditions are maintained for all, one may draw conclusions about the steel. Not about the technique (which is not evident in the article anyway). What you did was a knee-jerk reaction to a test using "modern" steels, and sought to demonstrate the superiority of vintage steel. I do not know how you could "repeat" my tests when you used different steels. This is just such nonsense.

Regards from Perth

Derek

[Prashun Patel]

Luke, I hope you can sift through the debate here and distill some practical, useful info for your situation. I wanted to elaborate on my point:

Since I stopped dragging my plane on the back stroke (thanks, Warren), taking more deliberate passes (thanks, David Charlesworth), and setting the chip breaker and lateral adjusters properly (thanks Brian H/David Weaver) I find that I'm struggling less and less with my strokes; it takes fewer to accomplish what I'm after. This ends up in far more blade longevity than would have adding an intermediate stone or changing the way I strop.

I also find that I'm stroking on my stones less, with more deliberation. Everything slowly becoming more efficient. All this adds up to less manipulation of the blade, and less use. Don't get me wrong, materials and details about metal structure must be critically important, but I submit that this is only the case when you've reached a level of proficiency of Patrick, Stanley, Derek, and Warren. If you are earlier on the learning slope as I am, then my money is on 'honing' your technique, not changing your materials.

[Robert Engel]

My head is spinning trying to understand all the microscopic/atomic science so I'll just say in the real world edge retention is going to boil down to 2 or 3 things:

1. Quality of the steel
2. Material being used (eg. pine vs. jatoba)
3. What is being done with the tool (eg edge grain vs. long grain)
4. How the tool is sharpened

I'm sure I'll be corrected if I'm wrong, but I keep it simple and take all my blades to 8000 grit waterstone and 5 or 6 strokes on a strop just for extra polishing.

More to the OP's question, I think the most important thing regardless of what steel your tools have, is find and develop a sharpening system that gives you consistent results and gets you back to work in a minute or two.
For me, this is a few strokes on 1200 diamond plate > 4k water > 8k water > few strokes on leather.
If I've waited too long, I'll start with 800 and if its a fine touch up I go straight to 8K.

I suggest you try hollow grinding and see if that doesn't help you a bit.