Holding an edge

[sappyg]

I've debated on whether to post this question elsewhere but in the end I figured traditional folks are more likely to carry (and use) knives over a longer period of time.

Having added a few older slipjoints to my growing collection of pocket knives I've noted that all, or most, were dull despite obvious sharpening. Some still have the factory edge and they seem OK but not great. Some factory edges rival Queen but that's for another post.

My question is does an edge, with little or no use, loose it's sharpness over time? If so does the steel make a difference?

 

[Curtis_Lowe]

I've heard of it happening with carbon steel I can't say that its happened to me but I regularly sharpen my knives.

here's a thread with more scientific answers http://www.bladeforums.com/forums/showthread.php/505523-Do-unused-knives-get-dull

 

[Obsessed with Edges]

The only valid reason I've heard, for a sharp edge becoming significantly dull with time and little/no use, is due to so-called 'micro-corrosion' (with carbon steel) of the edge. We all know about rust, and how it can weaken metal. So, if there's microscopic corrosion (rust) at the very edge, and that corrosion is allowed to remain & propagate, portions of the steel at the edge will essentially break down & erode away. Having said that, I've never seen it in any of my knives (so long as I didn't allow them to rust away).

Wire edges have frequently been blamed for the 'dulling' of a seldom-used edge over time. It's easy to miss-read that way. An edge gets sharpened to hair-popping, and the blade 'tested' with a few light cuts in paper, cardboard or whatever. Then, the knife gets put away for a long while, and when somebody picks it up again, it's mysteriously gone 'dull'. Not because the edge just deteriorated on it's own, but because those few light cuts in the paper or cardboard succeeded in folding over the wire edge left when it was previously sharpened up, 'tested' and then put away.

EDIT: I used to notice this with my own knives occasionally, before I discovered the benefits of stropping (including learning how to get rid of wire edges, so they won't drive me nuts anymore ). Once I had a handle on that, no more 'mysteriously' dulled edges on unused knives.

 

[sappyg]

That makes good sense David.

From time to time I 'think' I notice a slight change on some carbon steel blades that I don't carry often. A strop brings the edge up quickly. It doesn't take much. Yet others (carbon) seems to remain in a perpetual sharpened state.

Thanks Curtis_Lowe for the link. That clears things up.

 

[Obsessed with Edges]

I think there are some valid points in the thread linked by Curtis_Lowe, especially in regard to very thin, fine edges. It's not really surprising to me that an edge that thin (like a straight razor) could be dulled by almost anything, like rubbing a fingertip on the edge to 'feel' how sharp it is. The flipside of that is, it's also very easy to freshen it up again, with a few light, careful swipes on the jeans or a strop. Some people even strop their blades on the palms of their hands.

I'm in the habit of wiping down my blades with Windex or alcohol, immediately after stropping or before putting them away, and have frequently wondered if the paper towel or tissue I'm using has adversely affected the edge, however miniscule the change might be (it's a sickness, I know). So, my latest adaptation to that possibility is to wipe the blade with the tissue laying flat on my strop, as opposed to just pinching & rubbing the blade in the tissue between my fingers.

 

[richstag]

Hi David,

I think if touching the edge with a piece of tissue is noticeably dulling your edge then it may not be right. One quick way to remove a MICRO burr is to cut paper towel. You can then go back and strop or hone lightly to refine the edge further.

Worth a try. It was a trick I learned using my Kalamazoo. From what I found when you are stropping with an abrasive compound you are still sharpening and you can raise a micro burr if you keep at it too long.

For this reason I have come to like a linen strop. It really does no more then to remove burrs and micro burrs.

Idk, but what your saying doesn't sound in line with my experiences. Maybe this is helpful?

 

[Obsessed with Edges]

Kevin,

I don't actually see an issue with the tissue dulling the edge, I just keep worrying about it. That's the sickness I referred to.

 

[richstag]

Okay, but it doesn't sound normal to me

 

[Peregrin]

Kevin,

I don't actually see an issue with the tissue dulling the edge, I just keep worrying about it. That's the sickness I referred to.

I think you should buy two slipjoints and call the doctor in the morning.

 

[Obsessed with Edges]

I think you should buy two slipjoints and call the doctor in the morning.

Hmmm...

I seem to recall, that's how this sickness took hold in the first place...