Strange pattern on Fallkniven U2 blade

[Carboniferous]

I just picked this up online and after receiving it noticed a strange pattern of what appears to be some kind of corrosion (still completely smooth to the touch) on both sides of the blade, but most prominently on the back of the blade:

Any idea what this might be? It was advertised as brand new.

 

[traumkommode]

Aliens.

I dunno, man. That's interesting looking. The spots decrease in size with the thinness of that stainless laminator, so I'd say whatever it is runs all the way through that outer slab. Is it on the other side of the blade?

 

[Mikael W]

Never seen anything like it before!
Spotwelding marks?
I suggest that You email the pic to FK and ask.



Regards
Mikael

 

[Carboniferous]

Yep, it's on both sides.

Never seen anything like it before!
Spotwelding marks?
I suggest that You email the pic to FK and ask.



Regards
Mikael

They certainly looked like spot welds to me, but I can't imagine a context in which they would've been left there. The lamination process came to mind but I wouldn't think it'd result in spots like that.

 

[Mikael W]

Yep, it's on both sides.





They certainly looked like spot welds to me, but I can't imagine a context in which they would've been left there. The lamination process came to mind but I wouldn't think it'd result in spots like that.

I agree and the whole thing looks unique!


Regards
Mikael

 

[Carboniferous]

Fallkniven got back to me saying they didn't know, but that it was probably some kind of oil. I had already cleaned the blade once, but this time I used dish soap followed by isopropyl alcohol; the spots seemed to disappear until I touched the blade, the oils from my fingers made them reappear. Seems to be some minor defect in the surface that is only visible (or at least much more visible) with a film of oil.

 

[jfindon]

I think it's kind of cool.

 

[Dangerously]

Just bizarre.

 

[Daniel]

It looks to me like they had something applied to the blade and then removed leaving a stain on the blade. I had a blade that the dealer had stuck a price label to it and it placed a stain on the blade even after the glue was removed. It still has the shadow on the blade where it was located.

 

[aleforme]

Weird. The spacing looks exact. Like something hard was laying on the blade. It tappers off toward the edge as the steel curved off and lost contact so this happened after the blade was ground. Guessing it was something ridged with some type of chemical residue on it? Could be a million different things. I'd keep it. Looks cool.

Edit: Actually looks pre-grind based on the one high spot at the back of the blade.

 

[Danke42]

Some kind of paper wrapped around the blade during production that transferred to the finish?

 

[brandoak]

My guess is It's marks left from the heat treating rack/tray. ...or a forced patina from coming in contact with some sort of acidic chemical on a rubber mat...

 

[mete]

Now everyone will want one !!!
The laminations are not spot welded , they are made by rolling the three layers.
Something has discolored the steel but it's certainly strange !

 

[Dangerously]

 

[Carboniferous]

I received another prompt reply from Fallkniven, they remain stumped and are contacting the Japanese manufacturer. The story continues!

 

[brandoak]

Wonderful company, they will do you right.

 

[Raylas]

...Huh.

If you don't want it, I'll take it.

Honestly, looks kind of cool to me. If it doesn't cause a problem, I say keep it.

 

[Grandmaster]

^^^^^^^^^^^^^^Giorgio!!!!!!!!!!!!!! I laughed soooooo hard,

 

[powernoodle]

See how the marks are more prominent as the blade thickens from edge to spine? I would guess that it has something to do with the manufacturing process, especially the lamination.

But on the other hand, I have no idea what I'm talking about.

 

[Carboniferous]

The factory manager's take:

"However, the factory manager told us that the pattern is looks like “buffer sheet” pattern which we use for slip-proof sheet when we laser engrave the logo on the blade.

The sheet is made by rubber like material and its very soft, and it has a checkering pattern about 5mm square, so as one possibility, the laser have heated the blade and melt the sheet, then the sheets left their square patter on the blade. However, as you know, we check all blades and wipe off all stains at final confirmation, or we might overlook some chemicals on the blade, and it might cause a chemical reaction very slowly, but we haven’t heard and haven’t seen this kind of problem before.

In any case, please give us some more time to investigate the cause of this matter. We would like to ask laser company and steel company if they have a precedent or any idea about it."

I can confirm that the spots are roughly 5 mm in diameter.

Fallkniven has also offered to replace the knife if I'd like, but I think I'll hang onto it. Doesn't harm the performance at all and is definitely unique. Really great customer service on their part!