Hi everyone!

I just received a new Frosts Mora Clipper utility knife. The first thing I noticed though, is that the blade looks very funny. Is that a result of the blade being "high carbon"?

I used it to cut through a banana, rinsed it under the faucet, dried it with a towel and now it has these ugly stains, as you can see in the pictures.

Are high carbon knives supposed to stain and be ugly like that?

Don't call it an "ugly stain", it's called a "patina", and yes, high carbon does that, when it does enough of that, it's actually very attractive, and if you like, you may call it "natural blueing" <img src="/images/graemlins/wink.gif" alt="" />

Troy

That's real steel, baby! None of this hich chromium silliness.

I suppose you could get rid of it with a very stiff toothbrush and baking soda paste, but why bother? But you'll have to spend hours doing that, and it will happen every time you use this guy. That layer IS oxidized, but it will protect the blade underneigth.

Can it be powder coated?

Mora knives are intended for use all year round in a north European (semi-tropical to subzero) enviroment. Most chrome blades will become brittle at the bottom end of this temperature range. Unlike carbon steel. They are also a "cheap" knife. Unlike most cheaper knives they perform very well. However they will rust and cannot be abused. Not that you should be using your knife as a prybar anyway. I use them, I like them & bearing in mind their limitations I would choose one or more for a survival kit over many so called better knives . Best way to protect the blade is to apply a light coat of dry anti-rust lubricant or vasaline.

Here's a spectacular post on sharpening knives:
eG Forums

The reason I'm posting it to this particular thread is that there is a section called "Carbon Steel versus Stainless Steel" (in Section Two: Steel, in the first post), which gives a nice brief rundown of the pros and cons of Stainless and Carbon Steel, and within a nice explanation of why the patina showed up so quickly on the high carbon blade.

Some years ago, when I bought my first custom knife, I used it to cut a slice of ham. The blade was "stained" immediatly.
I went back to the knifemaker's shop where I had bought it ... not sure if it was a defect or not ....
But that's carbon steel to you, as other posters have explained..
and yes, after some use, it gives a nice patina.

Thanks everyone for your informative replies.

I have read more about this patina effect on Wikipedia. I'm not sure if that would present a health risk when using the carbon knife to cut foods, etc? Isn't the patina effect some kind of "corrosion" <img src="/images/graemlins/shocked.gif" alt="" /> happening on the blade?

Sorry Bee but that is so funny!

I suspect your mother used carbon steel kitchen knives when you were young. Stainless Steel is now used in most knives, we are shocked when we get a carbon steel knife.

Bee why did you select a carbon steel knife over the stainless steel version of the Mora?

Bee, no worries. Some of my kitchen knives are carbon steel butchers' knives I inherited: they've been in use for perhaps 80 years. I've experienced no health problems from them, and in fact they caused me to grow a third eye (which is a redundant survival mechanism).

Another benefit which I noticed among the guys I camp and hunt with: no one ever asks to borrow my carbon Moras. I have several of them in the cook kit, and one on my belt. NO ONE ever asks to borrow it!

I have several very special fixed blade knives from custom makers, and high end production fixed blade knives. I carry and use the Mora! Because it is so inexpensive I don't hesitate to sharpen it in the field with the Sterling sharpener or some other similar "scraper" type sharpener. Something I'd never do with a higher cost knife. Therefore, it is always scary-sharp; it is easily "touched up" when it gets the least bit dull; no one wants to borrow or use it because it looks so yucky; and I've never found a camp task (an APPROPRIATE camp task for a knife -- no limb hewing or pit digging) it couldn't stand!
You made a fine choice.

Aaaaaaaah!

You changed the edge profile on a Mora with a scrapper sharpener? It is the world's easiest knife to sharpen with any stone or diamond plate. In 98.6 Cody says a blind man could do it!

Sorry!

I couldn't help myself! I'll go sit in the corner now. <img src="/images/graemlins/blush.gif" alt="" />

A carbon steel knife should develop a nice blue/black color. Your blade should get darker as you use it. This is due to the formation of magnetite (Fe3 O4), the black oxide of iron. This is the same thing you get as you use your cast iron skillet or dutch oven.

It is a good thing. This thin layer of Magnetite gives some protection against the formation of red iron oxide (Fe2 O4), i.e. plain old rust. Note: that is SOME portection. Leave the blade wet or use around salt water and it will still rust.

If anyone says anything about your knife, tell them your knife has a classic cold blued finish that you just cannot acheive with plain old stainless blades. <img src="/images/graemlins/grin.gif" alt="" />

If you damage the edge, run a course diamond sharpener over the edge, followed up by a fine one. Job done.

Yep Craig. I did! In fact ALL of my Moras have been "reprofiled" by dragging thru the scraper. I can sharpen any knife I've run across "properly", but for my Moras (and yes, for my Opinals) I BOUGHT them so I could just run them thru the scraper one or two licks in the midst of a cutting job. I can live with the shame.