Are certain blade shapes easier to sharpen?

TRfromMT

TRfromMT

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So, hypothetical, all things being equal for a particular steel - let's say you have a variety of knives, all of one type of steel, same heat treat/hardness, same primary bevel and edge geometry. The only (ONLY) variable is the blade shape. Let's say you have a lineup of knives with a wharncliffe, drop point, skinner, sheepsfoot, etc...

Also, you are only sharpening on one system - say a Sharpmaker, or a strop, for all of these blades.

Do you find one blade shape is easier to sharpen, or one shape is harder for you to sharpen?

I am working on a very straight edge wharncliffe in a steel I am familiar with, and I cant seem to get it to the same hair-popping sharp as my other knives. I'm using a Flexx strop for my final edge. Mostly I can get a knife to shave, but not so the wharncliffe.

Just curious about your experiences. Thanks in advance,

TR.
 
My guess is about blade thickness on the edge, not shape at all. But recurved edge blades require more attention and thinner stones (or the edge of the stone) or rods.
 
TRfromMT said:
So, hypothetical, all things being equal for a particular steel...[the]he only (ONLY) variable is the blade shape...Do you find one blade shape is easier to sharpen, or one shape is harder for you to sharpen?
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On a stone, the straighter the edge and the fewer the grinds, the easier and less time consuming to sharpen. Wharnscliffe and sheepsfoot top the list. Not necessarily more difficult, but blades with multiple grinds, large bellies, tapers and/or reinforced tips and a heel which meets the quillon take me more time to maintain due to the number of angles that must be adjusted for per pass. At least until muscle memory takes over...

I am working on a very straight edge wharncliffe in a steel I am familiar with, and I cant seem to get it to the same hair-popping sharp as my other knives...
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So all things being equal with the only variable being the steel, you are able to get a drop point sharp, but not a wharnscliffe? What steel and what knife :) ?
 
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Assuming that you are hitting the apex, I might switch abrasives. From Spyderco ceramic to something less dense.
 
The knife giving me problems is an ADV Pocket Butcher. It actually is the only D2 blade I have, and currently the only wharnie I have. There are a lot of variables, I know, I know...

I was just starting a conversation about blade shape only. I've never seen it discussed, but have of course seen ALL of the other variables in sharpening discussed.

Somehow I just haven't developed the feel for this blade yet. Among other things that are affecting it, I got to wondering about the shape...
 
TRfromMT said:
The knife giving me problems is an ADV Pocket Butcher. It actually is the only D2 blade I have, and currently the only wharnie I have. There are a lot of variables, I know, I know...

I was just starting a conversation about blade shape only. I've never seen it discussed, but have of course seen ALL of the other variables in sharpening discussed.

Somehow I just haven't developed the feel for this blade yet. Among other things that are affecting it, I got to wondering about the shape...
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My Pocket Butcher sharpened up quite easily for me, but I was using Atoma diamond plates...D2 on anything but diamonds has been an exercise in frustration from my experience.

~Chip
 
Some shapes can be much easier. I find blades with a long, sweeping belly, like drop-point or clip blades, to suit my sharpening passes on the stone more closely. A santoku-style blade on a kitchen knife is also very easy, with it's long, subtle belly on an otherwise straight edge profile.

A sheepsfoot should be simpler, but often isn't, if it's a crinked blade in a stockman or similar multi-blade traditional with more than one blade on the same spring. The crink in the blade (it's usually the sheepsfoot) adds difficulty in getting all of the edge in flush contact on a flat stone. Even without the crinking, these blades are often not fully straight anyway, with some subtle warp/curve, or troughs due to belt-grinding the profile at the factory. This includes wharncliffe blades as well.

As mentioned, the D2 steel may be more the issue, and additionally complicated if the existing grind is very thick behind the edge and/or obtuse at the apex. If the stone in use isn't up to it, that'll account for 99% of the frustration. A SiC stone or diamond hone will make it much easier, if you're not currently using one of these.


David
 
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I have several knives in 3V, including a few in the Delta 3V heat treat (Carothers, Survive!). 20CV (Survive!), S35VN (Chris Reeve Knives), and a spyderco in M4. I haven't had any issues with any of them.

I had a spyderco in S110v and it gave me fits.

I use a sharpmaker, and have only recently (like in the past 2 weeks) started finishing on a Flexx strop.
 
I did take the D2 pocket butcher down to 15dps on my diamond rods on my sharpmaker, then finished up through the ultra fine rods, finally putting a 20dps micro bevel with the ultra fine rods. I had it to slicing phone book paper, even able to do the standing PB paper cut test. Then some time on the strop and the edge has gone. I got it back, but I can't quite find the technique on this blade yet.

My point is that I have been able to achieve a solid, hair popping, phone book paper slicing edge on all my knives with my setup consistently, and now the strop... with the exception of this blade which I did and now can't (consistently).
 
By all accounts, a wharncliff should be the easiest to sharpen. If you're spending the same amount of time on the D2 as the other steels, that may be where your problem lies. I've found that I have to spend more time with D2 than most other steels.
 
TRfromMT said:
I did take the D2 pocket butcher down to 15dps on my diamond rods on my sharpmaker, then finished up through the ultra fine rods, finally putting a 20dps micro bevel with the ultra fine rods. I had it to slicing phone book paper, even able to do the standing PB paper cut test. Then some time on the strop and the edge has gone. I got it back, but I can't quite find the technique on this blade yet.

My point is that I have been able to achieve a solid, hair popping, phone book paper slicing edge on all my knives with my setup consistently, and now the strop... with the exception of this blade which I did and now can't (consistently).
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Losing the edge on the strop might be telling you what's going on. To me, it sounds like a sharp burr may've been responsible for the successful cutting tests prior to stropping, and then the strop removed it. That's the risk with the ceramics of the Sharpmaker; it's very easy to create burrs on them, and some steels will be more vulnerable to it than others.

The same sharpening strategy isn't always the best for individual knives or steels, and taking each and every knife through all the same grit stages and stropping regimen won't necessarily produce the same results, across the board. In fact, as steel types are different, results will almost always vary as well. Need to watch with each one, to see where each will 'peak' in sharpness, in which stage of sharpening/refining. Adapt specific strategies with individual knives, based on what you see works best for each one.

D2 usually responds very well straight off a diamond hone. In the following refining stages with D2, you have to be very, very careful not to inadvertently diminish results off the diamond hone. D2 refines better and more easily, if followed either by additional diamond at finer grit, or with hard-backed stropping techniques; that could be stropping on bare wood with suitable compound (diamond, aluminum oxide, black compounds work well with D2 on hard backing), or on something like denim or linen stretched very tightly across a hard backing of wood, or glass, etc., using the same compounds.

I've never much liked ceramics for refining edges, as there are too many vulnerabilities to burring with them, in part due to their hardness, their tendency to load up and clog very quickly, and very narrow contact area on the edges of ceramic triangular rods, which exerts a lot of focused pressure against the edge. In terms of polishing an edge or cleaning up burrs, other methods will be easier, and will also produce better results (sharper, less burring, more efficient and faster de-burring), as with the hard-backed stropping I mentioned above.


David
 
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Some shapes add a challenge to sharpening such as recurves or tantos ... just some added attention.

But for me at least D2 is the least favorite steel for me to sharpen on any blade shape ... it just seems to give me troubles ... that may be what you're experiencing. And I know some steels should be similiar or harder to sharpen but for me its D2 that gives me fits ... and it doesn't seem to matter what equipment I use to try to sharpen it.
 
D2 can be very frustrating when it comes to stropping. I'd avoid it entirely and substitute with a microbevel, or use a harder surface than leather for your compound. A sheet of paper laid over a benchstone works better. Lastly, diamond honing compound will be a big help as well.
 
I always find it easiest to sharpen a tanto blade free hand. Most of the time I use a lansky guided sharpener and find no problem sharpening most blade types. The only shape i haven't attempted is a recurve
 
I think the a mixture of the thickness of the blade and D2 being a hard steel is the issue. For me d2 works best with a coarser edge but if you want a more polished edge after diamond stones go to a steel for final touches
 
Echoing what others have already said. I never strop the EDC in D2 and set a 15 dps apex on an Atoma 1200 after coming off a SPS II #1000 at 12 dps.
 
Some blade shapes are more challenging than others and small nuances in this can also differ between various people and their technique...

You can strop with just leather to make sure small burr is gone, after your UF spyderco.
This won't dull your knife and you can get a good practice of the mechanics with whatever blade shape you are working on.
When the knife get's duller try bringing it back up to being hair popping with that flexx strop you got. See if you can get it as crisp as what you get from that UF spyderco microbevel. Since that microbevel you made is tiny. Don't try to match it's angle on the strop. Just strop with the 15dps angle you made earlier and see if it's getting sharper. Better to start lower and see how it's doing.
I like HeavyHanded tip to use diamond compounds. They just abrade better, but see for yourself.

Stropping in this scenario is for convenience. Your edge is already super polished and you are just polishing it up more. Convexing it a bit while at it.
For me, I like toothy edges and have to think through the sharpening and maintenance process a bit differently when introducing a loaded strop into the mix.
 
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