S90V going dull without use

Jason B.

Jason B.

Knifemaker / Craftsman / Service Provider
Joined
Jun 13, 2007
Messages
11,196
This is something I have noticed for a while now and I also know if a mostly carbon blade is left untouched for a while it will become a little duller (not by much) because of edge corrosion. The problem that I am having is by the next day I can feel a burr on the edge and it has lost all ability to whittle hair. Its not that the knife is not sharp anymore but its not nearly as sharp as when I left it. I don't even get this much edge loss with my 52100 mule and it sits much longer without use. Is it just the steel or is it a combo of the steel and how fine of a edge I am putting on it?

Its not a big deal because a few passes on a strop and its fixed but I have never seen a steel that does this so fast.
 
I'm clueless-a burr? I get the the whole corrosion thing, but not the burr. Get a Marine Cloth by Tuf Cloth or put lots of knife or gun lube all over the blade.
 
I am sure it would be ok then because atmospheric corrosion would not be possiable. My question is more why is it happening so fast.
 
My S90V Military hasn't gone dull when left in it's box for a couple weeks on end. Could it just be you're just sensing it wrong? S90V and S30V have outstanding edge retention, but they loose that insanely scary sharp edge quicker then say ZDP.
 
Maybe a housemate is using the heck out of it while you are asleep! Or you are sleepwalking and sleepknifeusing VERY DANGEROUS!
 
Edge after sharpening

pics.jpg



Next day
micropics.jpg
 
knifenut1013 said:
Edge after sharpening

pics.jpg



Next day
micropics.jpg
Click to expand...

I honestly don't see much of a difference. It's a bit grainy and the color is off though.

I would run it through a full sharpening set on my sharpmaker. 40 strokes a step, all four steps. This should burn off a layer of metal. It could be that the edge was over heated when it was being ground. You're looking to take about 1/16th of an inch off the edge. Use the 30 degree slots.
 
The Mastiff said:
Is it in a sheath? Joe
Click to expand...

Missed that post.

If you're storing it in a sheath it might either (a) kydex will dull the knife slightly when inserting and removing or (b) leather sheaths are corrosive. Shouldn't have any effect at all on S90V, in my experience it's very stainless, but the edge is quite thin, and the surface area exposed is greater. It might have something to do with it.
 
knifenut1013 said:
Edge after sharpening

pics.jpg



Next day
micropics.jpg
Click to expand...

Well acording to that pic, you've got a lot of shine.

When you look at the edge in bright light (directly under a lamp or on a bright sunny day), is the edge completely smooth, or do you see specks of shine on the very edge holding the knife upside-down? Rotate it around in the light and check.
 
Looks like the edge from the second day is better.
But honestly what is going on with that...?
 
I am trying some new pic's now, I am having lighting problems and the shine of the polished edge is not making it that easy either. I know its not that big of a difference but notice how in the second picture there is more "teeth" and a roundness to the edge.
 
knifenut1013 said:
I am trying some new pic's now, I am having lighting problems and the shine of the polished edge is not making it that easy either. I know its not that big of a difference but notice how in the second picture there is more "teeth" and a roundness to the edge.
Click to expand...

I guess it kinda does, although from the quality that could just be grain in a gausian distribution along the edge. Meh.

If you discount the quality, it looks almost as if the edge in the second picture may have a small microbevel on the edge. If you microbevel the knife, you could just be messing it up...
 
knifenut

If this were actually happening, I have some carbon steel knives that, since it's years since they were last sharpened, should be dull as butter knives by now (if not wasted away to slivers). Exposure to just air won't cause noticeable changes to blade steel in a day. I'd be looking for some other explanation.

David
 
You must log in or register to reply here.
Back
Top