Cliff,

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-are all blades being used for the same work

No. Two of the knives are doing the same work, the M390 and PM2, one isn't being used at all, the AEB-L knife

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-are some blades being not used at all

Yes, the AEB-L knife.

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-which ones are cleaned

The M390 and the S30V

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are they used and cleaned

Yes, the M390 and S30V

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-are some not used and cleaned
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Yes, the AEB-L

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are any not used or not cleaned

Yes, the AEB-L.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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Jason,

I can't quite understand what question you are trying to answer, as there are a lot of things changing at the same time. All experiments start with a question - so what exactly do you want to know/investigate?

Cliff,
I am having an intermittent issue with high sharpness disappearing, going from tree-topping sharpness to shaving sharpness, even when the knife is not being used. This is varying from knife to knife, edge finish to edge finish, carry type, and in my heaviest use and in no use at all. I want to keep the high sharpness whether the knife is being used or not, for up to a week, as I have done before. This is my standard that I am used to having for a knife. I was then thinking that since it might be a corrosion issue, I could test to see whether it is a steel type issue or a apex grit finish issue, or maybe a use/non-use issue. I had been successful with restoring the sharpness back to being able to tree-top arm hair by using a hanging strop with the linen and leather components, no abrasive compounds being used. What I have noticed so far is that the coarser edge finish is degrading the fastest, even though it is in the most corrosion resistant steel (M390) and carried in more ideal conditions, with light use. The blade that has a more medium finish is showing better results, even though it is in a less corrosion resistant steel (S30V) and carried in less ideal conditions. The blade that it is doing the best has the highest grit finish, even though it is the least corrosion resistant steel (AEB-L) and the worse carry conditions.

This is what I have noticed in the last three days. I was wondering if I should keep doing what I was doing, and seeing what happened, or trying all the blades with a high polished edge and see if that solves the issue.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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Jason, ok you have a lot of questions, and it generally isn't useful to try to answer them all at one time :

-is there a difference in edge retention among three steels in normal use
-is there a difference in edge retention in a given steel, if it is left alone dry vs oiled v cleaned

These are two different experiments and you can carry them out at the same time. Something like :

-take the m390 and s30V knife, carry them and just switch from one to the other every time you have to do something
-record hold long they go until you have to sharpen them

Repeat this a number of times, say 5-7 and see if there is consistent behavior.

While you are doing this :

-take the AEB-L knife, don't use it, check the behavior, see if the edge degrades at all, if it does record the time

Repeat this a number of times, say 5-7 and see if there is consistent behavior.


Then you can swap the knives out, carry the AEB-L and the S30V and use the m390 in the unused experiment.

Then swap once more, AEB-L and m390, and use the S30v in the unused experiment.

Cliff,
Awesome. Thank you.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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Cliff,
Again, thank you. The first part of the testing is the same as what Kyley helped me work out, so it is good that we got that part right. I just wasn't sure were to go from there, and you helped immensely with that. I have the unfortunate behavior of testing multiple things at once, whether it is knives or computers, and it makes my life difficult. Simple is more often better for testing and debugging.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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I have been thinking about if people learned how to strop first on plain newsprint, leather, ect. they could develop proper stropping technique. That way they won't mess up there edge as easy and can tell by sights, feel and sound when they are doing it right. Once they are getting good results with plain stropping, they could move to stropping with compounds.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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jasonstone20
I have the unfortunate behavior of testing multiple things at once...

It is possible to do that, sometimes you have to -BUT- the statistics get so much more complicated and you need so much more data. As a general rule, the more you isolate :

-the simpler the analysis
-the less data needed to draw conclusions

I have made two observations so far. Just for fun, I decided to check the 555 Benchmade Mini-Griptilian, and see if it would tree-top hair. I set it aside a few weeks ago when I got the Spyderco Lil' Matriarch. I had lowered the angle, and put a polished edge on it. It still tree-topped hair, just like the AEB-L knife. Both knives have low angles, and high polishes. These two things tend to favor tree-topping arm hair. I am thinking how I am testing high sharpness is flawed. Plus I am running out of arm hair on my left arm !

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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Quote
jasonstone20

[...]

Another thing that might be interesting is where these knives are being worn, i.e. how close the the body they are worn, for humidity and sweat factor. The AEB-L knife is around my neck, in a sheath, worn directly on the skin (Also worn 24/7/365). Often, there will be moisture on the blade when it is extracted from the sheath. The PM2 is worn inside the waist ban, against my base layer of clothing. The M390 is worn cross draw on my belt, with a shirt hanging over it. The PM2 is also worn when I sleep, the M390 stay on my pants.

[...]

Jason, are these leather sheaths or kydex/plastic?

If it's leather, the leather could well be holding moisture, especially if absorbing sweat and humidity from the air etc.

Suggestions I can think of for testing loss of sharpness in storage, in addition to Cliff's notes about carry & usage A/B testing:

• Store without the sheath to remove that as a variable
• Store wrapped in rust preventative paper like Armor Wrap VCI paper
• Try storing in a drawer or box with dessicants to see if reducing relative humidity matters

-----

-Jay

jloden,
Kydex. Kydex can abrade away a fine sharpness edge also if it isn't built correctly. Kyle makes awesome sheaths, they don't have that issue.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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I think I am reaching the limit of what I can achieve with plain stropping. I believe the metal on the edge apex is becoming fatigued, because I am having to do twice as many passes on the strop to get the edges on the M390 and S30V blades. I am going to see if the passivation helped. If not, I will resharpen both blades tomorrow, and then try the passivation process again.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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So, the M390 and the S30V blade are still tree-topping arm hair, but just barely. Both knives haven't been used during this time because I have been saving the cardboard for testing.I am thinking that the edges were fatigued from all the stropping, it was over 400PPS total for both knives, so about 200PPS each, along with use. I have some cardboard saved up for cutting. After I do the cutting I am going to resharpen both blades on the clone of the Edge Pro Apex with the Sigma II Select Stones, then do the passivation process for 30 min like I did last time, and see how everything lasts for a week of normal use.

edit:
I am going to strop the blades back to full tree-topping sharpness before the cutting test.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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Edited 1 time(s). Last edit at 06/28/2020 05:09PM by jasonstone20.

Update:
It only took 20PPS on linen and leather to refresh the edge on each knife. That is an improvement, as it was taking a up to 80 PPS for the edge to be arm hair tree topping again.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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So I used the clone of the Edge Pro Apex I have, along with the Sigma II Select stones (250, 400, 1200, 3000, 6000, 10000) and then the Spyderco UF, followed by 1.0 micron diamond paste on leather for a strop. The edge is a mirror polish, and so far for the last few days it hasn't lost high sharpness. I didn't use the passivation process.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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Ok, here is me cutting a weeks worth of cardboard with the knife I got from Kyle, the KWB M390 knife (44min long):

[www.youtube.com]




"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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This is the strop I have:
[www.worthpoint.com]

This is what is kind of looks like:
[www.ebay.com]

I don't think I have the 18000 model.

This is the one I have:

[www.etsy.com]
[www.etsy.com]

I just sanded it to recondition the leather, and it took the gold marking inlays off a little. A lot.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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Edited 2 time(s). Last edit at 07/13/2020 05:31AM by jasonstone20.

If the strop is worth that much, i'd sell it and use a piece of cardboard with compound fresh each time you need it. you can just start cutting your boxes into 3"x6" strips ;D

----------------------------------------------------------------------
It's not Cliff, its Dr Stamp
#kebabstickcut, it's a thing - make it happen

cKc,
No way. They don't make strops like this one anymore. I like old vintage stuff, especially if it is still usable. These aren't that easy to find in good condition.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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I got a new Trend 8x3 strop to check some things that I had investigated in this thread, and to use along with the Tormek T4, since I was having issues getting the smaller wheel to polish in the larger wheels grind marks, although it would polish at the edge and the shoulder, but not the middle. Anyhow, what I wanted to post about hear was that Kyley was right, the dark swarf marks I was seeing on the hanging strop, both components(leather and canvas), was from the previous abrasive. I discovered this with the Trend strop, which was brand new. I put Tormek compound on the rough side of the leather, and even when I wiped the blade down, it left swarf marks on the plain leather when I used the plain side of the leather.

Trend 8x3 Strop

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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you need to be wiping down with pure alcohol or some form of dissolvant to really get the blades clean. no matter how clean you think it is.. it never seems to be when you use a solvent

----------------------------------------------------------------------
It's not Cliff, its Dr Stamp
#kebabstickcut, it's a thing - make it happen

I get the best results from plain stropping if I do it after pasted stropping. I don't think plain leather can deburr an edge all by itself.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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