blades going dull by just sitting

[rickm]

ok tell me im crazy, i always sharpen my knives before putting them away. when i go back to them after a day or two i notice that they arent as sharp as when i left them. I re strop them. seems like they are losing the edge just by sitting idle. hard to believe as nothing touches them but seems real enough. I have good quality knives, cape forge, dunkels and trevor abletts, so its not a bad knive or bad steel.
they are not horribly dull but do require a couple passes to bring back. ther isnt any rust etc on them. am i imagining this?

[Robson Valley]

I think you're quite normal. I have no solution to the puzzle. Of all my carving tools, I have a Pfeil 5/35 gouge which changes it's bevel angle overnight. Same place, same carving, and I have to lift my elbows another inch or more. Back to the 4000 grit then hone again. Tomorrow? Do it again.

[Donna_T]

I suspect only someone who specializes in metals engineering or chemistry can verify this, but I've always suspected my tools got duller while resting in my carving box. I, too, like to strop tools before putting them up after a carving session so they're ready to go next time. If it isn't an oxidation process, I can only guess that my estimation of how sharp they are when I put them away is tainted by how tired I am--compared to how much more alert I might be when I pick them up the next day.

Of course, I've always taken a beating by fellow club members who think my tools are never sharp! It's bad enough that when we get a new carver in the club, I tell them they cannot pick on my sharpening skills until they've been a member for a year!

[Coker]

Not sure how true this is, but I read many years ago that an edge put on a blade will dull by itself. I think the article said it happens more in higher carbon content tools. It has something to do with particles in the air reacting with the metal. I don't sharpen mine when done, I strop when I'm ready to start.

[Dicky]

I was told this by my mentor who had 50+ yrs. experience. I find that some do and others don't. It may have something to do with metallic content. I find the blades I make from files seem to stay the sharpest so they are usually my go to's if I don't feel like stropping.

[TreeWizard]

I believe if you looked at your edge under a microscope you'd find a coating of rust on the edge, not much, but enough to notice the extra drag of the blade.

[Buffalo Bif]

Interesting thread, thanks. I whittle till the piece is done or I'm too tired to continue, and always strop at the beinning of a session just because it feels like a warm up.

[Canopener]

I think there may be something to this issue. Even here in AZ where the humidity is very low most of the year, I have always felt the need to touch up my tools after a period of non use. The strangest thing was one time a few knives developed these red rust blisters that left pits even after stropping. I am sure something got on the blades in the first place but the chemical reaction kept working as they sat, and I did not knowingly put away dirty kinves.
Jim

[Stan Curtis]

I put them away sharp and stropped. Then do a quick strop on starting as a warm-up. The routine works for me.

[Robson Valley]

This thread made me decide to try to figure out what was happening with my 5/35 gouge.
I drew a bunch of parallel stripes on the bevel with a black felt marker. Gotta love that trick.
Lined up the gouge at 20 degrees on a 1k water stone. Made a few twisting pull strokes.
I was left with a row of black dots along the edge.. . . . . the bevel had to be a lot more than 20 degrees (somehow). The metal was coming off maybe 1/16" behind the edge.
Oh well. Fixed that, went on to 4k then honed the matte finish from the 4k water stone.
Test in my usual stick. Much better. No doubt an upscrew on my part, at least I can fix it.