Loss of sharp...over time?

[Deadboxhero]

[Xplorer]

.....
Is this my imagination? Or is a loss of sharpness actually happening over time, in the absence of any other dulling mechanism?

My friend, I have never met anyone as absolutely insanely obsessed with edges, edge formation, and sharpening perfection than my friend Shawn (Deadboxhero). To this day he still blows me away with the depths and lengths he will go to in an effort to create a perfect apex. Although I am one who is beyond reluctant to believe anyone regarding any knife related details until I've tested it and proven it myself I have learned through time, testing and many, many conversations that Shawn is the ONE AND ONLY person who can tell me about edges and I would be wasting my time to double check his info. If Shawn says it's a burr...my dude...it's a burr.

Because of my experiences with Shawn, every knife I make has an edge created with a very special vitrified CBN stone he created and all of my edges are final sharpened using techniques he taught me on the specific stones he told me to buy.

If you haven't checked out the videos Shawn does on sharpening and all the other apex related stuff he geeks about, check out his videos on You Tube. https://youtu.be/nHrGs3hCzgg

Best,
CK

[TomAiello]

With one of the USB microscopes you take a picture daily of freshly sharpened knife to see if there is something going on with the edge.

That would be an awesome experiment. Do a 6 month daily time lapse photo of the edge, or something like that.

[wrdwrght]

Is blade-steel inert? I think science says no.

Why would thermal perturbations in the environment and chemical reactions with the environment NOT have molecular consequences that we experience as dulling?

[Ric]

I also noticed that.
In the pocket are dirt, keys, humidity.

You a small touch up and it's fine.

I think it's dirt, burr, micro corrosion.

[Xplorer]

...Why would thermal perturbations in the environment and chemical reactions with the environment NOT have molecular consequences that we experience as dulling?

You're absolutely correct. Steel not only suffers molecular consequences due to chemical reactions (after all, mixing with oxygen on a molecular level is the actual definition of burning) but it also flows like a liquid as all things do as well. Adding water amplifies chemical interactions and adding salt water creates a perfectly conductive environment for corrosion to run wild. With some steels (like M4 in my experience) you can actually experience a notable edge degradation from corrosion due to salty humidity alone in just a few weeks if you're looking closely enough. Varying degrees of environmental stresses combined with the wide variety of steel types used for knives means that there are lots of people who will indeed experience molecular consequences that we experience as dulling.

However in this case since the OP is talking about a stainless steel and no extreme environmental stress factors, 2 months just isn't enough time to cause the degree of loss of sharpness that he described. The often elusive burr is the most likely culprit.

Best regards,
CK

[James Y]

I've opened boxes of kitchen knives made in the 60s never used that were still razor sharp.

Yes, I have pocket knives, both stainless and straight carbon, that I haven't sharpened since the '70s, that are still very sharp. And they haven't been kept protected in airtight containers.

Jim

[Pokey]

What if next time you sharpen, you then seal the knife in a baggy or something with a desiccant pack? For science?

Or like this?

[kodai78]

If you believe (and to be clear I do not) that the edge changes in any way while it’s protected in a drawer, why does it have to be less sharp? I think your perception of sharpness is influenced by something like confirmation bias. “I just sharpened it so it’s very sharp”. I would be willing to bet a large sum that a microsopic examination of the edge would reveal no discernible change at all after any interval up to decades.

[Bill1170]

I asked Mr. Stamp about this years ago and his theory was that during sharpening there was some elastic deformation and that with time the edge would “relax” a little and lose a little bite.

I don’t know if that is true but it has always stuck in my head.

That’s an interesting possibility to consider. Hmmm.

[Bolster]

Interesting: Some folks have experienced this, others have not. At least now I know it's not just me!

If the answer is "burr," what is the mechanism, how does that work? How would a burr mean sharp after sharpening and less sharp in several months?

[K1500]

I know Lance (Surfingringo) has mentioned that a freshly sharpened knife in something like VG10 will noticeably dull without use when left in a corrosive saltwater environment. H1 and LC200N don’t do this. This is a long ways away from leaving a knife in a drawer, but it is an example of a knife losing an edge without use.

[dj moonbat]

I don't think @Deadboxhero has enough information to state conclusively that it's a burr. But I do think that the best guess is that it wasn't all the way sharp; we're probably just looking at a situation where OP thought he was putting away a sharp knife but wasn't.

[Deadboxhero]

Interesting: Some folks have experienced this, others have not. At least now I know it's not just me!

If the answer is "burr," what is the mechanism, how does that work? How would a burr mean sharp after sharpening and less sharp in several months?

There's always a burr unless proven otherwise.

There's always some residual burr from when you break off the main burr, the base of the burr remains. That's when the real deburring begins.

Without proper deburring all you're doing in some cases is straightening that weak piece of metal out, some steels/hts are very prone to stubborn burrs as well.

Most people mistake this wispy, foil edge for a sharp edge because it is still capable of "cutting paper" and "shaving" but this weak piece of metal is not stable and can curl over even in hours depending on the severity etc

[Deadboxhero]

I don't think @Deadboxhero has enough information to state conclusively that it's a burr. But I do think that the best guess is that it wasn't all the way sharp; we're probably just looking at a situation where OP thought he was putting away a sharp knife but wasn't.

That's why it's called ruling things out. You have to start with the obvious most likely culprits before you can move into talking about the higgs bosons and quantum tunneling for reasons why the edge went dull.

It's human nature to talk about the most fantastical, exciting reasons for things but unfortunately trying to grasp a better understanding of reality means that you can't come to those conclusions until you've ruled out the more boring, basic things.

Once basic things are ruled out then we can get excited about chasing more exotic theories.

Otherwise all this leads to is a confusing mess and people getting misinformation.

[Deadboxhero]

I'm so flattered I don't even know what to say.

Means a lot to me, I've learned a lot about making knives from you Chad, particularly handles and finishes. You've always been the epitome of attention to detail.

.....
Is this my imagination? Or is a loss of sharpness actually happening over time, in the absence of any other dulling mechanism?

My friend, I have never met anyone as absolutely insanely obsessed with edges, edge formation, and sharpening perfection than my friend Shawn (Deadboxhero). To this day he still blows me away with the depths and lengths he will go to in an effort to create a perfect apex. Although I am one who is beyond reluctant to believe anyone regarding any knife related details until I've tested it and proven it myself I have learned through time, testing and many, many conversations that Shawn is the ONE AND ONLY person who can tell me about edges and I would be wasting my time to double check his info. If Shawn says it's a burr...my dude...it's a burr.

Because of my experiences with Shawn, every knife I make has an edge created with a very special vitrified CBN stone he created and all of my edges are final sharpened using techniques he taught me on the specific stones he told me to buy.

If you haven't checked out the videos Shawn does on sharpening and all the other apex related stuff he geeks about, check out his videos on You Tube. https://youtu.be/nHrGs3hCzgg

Best,
CK

[Bolster]

Interesting: Some folks have experienced this, others have not. At least now I know it's not just me!

If the answer is "burr," what is the mechanism, how does that work? How would a burr mean sharp after sharpening and less sharp in several months?

There's always a burr unless proven otherwise.

There's always some residual burr from when you break off the main burr, the base of the burr remains. That's when the real deburring begins.

Without proper deburring all you're doing in some cases is straightening that weak piece of metal out, some steels/hts are very prone to stubborn burrs as well.

Most people mistake this wispy, foil edge for a sharp edge because it is still capable of "cutting paper" and "shaving" but this weak piece of metal is not stable and can curl over even in hours depending on the severity etc

Right, I'm going with you on "always a burr" DBH, but what is the mechanism for "drawer dulling" (if there is such a thing)?

So let's say you sharpen a knife, feels really sharp, passes all the typical sharpness tests, but it also has a small burr on it, smaller than you can discern (I even use an inspection scope to look for burrs, so assume not even my inspection scope picks up the burr.) OK, now we put this knife in a drawer. Out it comes in three months, and it's not as sharp anymore.

What's the mechanism here? Has the burr curled over, collapsed, zig-zaged, multiplied, hosted a party, gotten obese, pregnant, or had a large family in the intervening months? What has the burr been doing sitting there in the drawer? If curling, why is it curling, does a burr naturally curl with time?

[Bolster]

Follow up question for DBH: How do we detect burrs that may have escaped notice previously? If we assume a knife may have a burr on it, even when we can't see or feel it, how do we know when the burr is gone? How do we "prove otherwise"?

[aaronkb]

I’ve had this happen a lot and it drives me crazy, although I live in DC where it’s humid af.

[Deadboxhero]

Spyderco factory edges average 150g BESS

Double Edge Razors average 50g BESS


Spyderco 10v REC



Tested when I got it March 2020



Tested factory edge 1.5 years later, it just stayed in box all that time.



Micro corrosion observed, but not enough corrosion to affect sharpness over a span 1.5 years living in it's box.


Double Edge safety razor, (same package of razors)



Tested March 2021



Same package, different razor, Tested 6 months later.





If you're edge goes dull sitting around in a "inert" environment, you have a burr.


We can't discuss More complex topics unless you guys are going to start sharing information more objectively and empirically.

This is why I was bringing up a point about USB microscopes in another thread.


It's not to see if you're getting your edge sharp, It's to share things more objectively and empirically for better discussion.


Otherwise discussions will just become bad episodes of "Ancient Aliens" on the History channel,
With everybody speculating wild ideas leaving the thread more confused than they entered.