D2 sharpness question

I doubt it. I've seen this occur on D2 and was standing in the makers shop when it happened. It can easily happen with D2 and it's from how this steel resists polishing with its V content. Should one work it a lot attempting to move it more toward a mirror polish it will take on a orange peel look. DM
 
Very good gentlemen.

I haven't gotten rid of all of the scratches, maybe that is a contributor. The grinder (high grit belt) did seem to remove all of the scratches on that part of the blade though.

pwet, those are beautiful pics and knives! You've absolutely inspired me to wash my blade. I need to know though, did you use ferric chloride acid, and if so, what was your procedure? Also, what was the finish before your treating it? I'll post pics when done. :)
 
"orange peel" is very common in D2, as well as some recent versions of 440C and 154CM that are not quite up to the original manufacturing standards. It has nothing to do with vanadium content or how much you polish it (CPM-3V has more than twice the V of D2, but can be taken to a very high polish with no "orange peel" look... it's not easy or fun, but it can be done). It's in the structure of the steel itself; it results from large clumps of poorly-distributed carbides. The more you polish it the more apparent it will be. Ever notice how nearly all D2 knives have a very basic satin or stonewashed finish? In part, that's why.

This structure is not necessarily a "bad" thing; many makers and users prefer D2 specifically for the way it takes and holds a toothy edge. That can be a good thing if you're cutting a lot of tough material like meat or hide. It's no accident that Bob Dozier has stuck with D2 all these years, and has developed an excellent HT protocol for it.


The powder version of D2, CPM-D2, does not exhibit the orange peel look; nor do any other powder/particle metalurgy steels I've seen. This is simply due to a finer, more homogenous structure.
 
thanks, that´s what i thought.

strigamort, the knives i posted arent mine, got the images from a french forum, the knifemaker is active on usn iirc jerome hovaere aka "torpen". you can see his work on facebook too, just forget about his site its not really updated. all i know is that those knives where hand rubbed then etched in ferric chloride, no stone wash or anything. what you see is just the structure.

here are picture of the damascus like knife i talked about. it´s homogeneous 145sc steel, forged and ht´d as hard as the maker could

%255BUNSET%255D.jpg

IMAG0041_BURST009.jpg


first pic is natural patina, second is ferric chloride etch after polishing the blade up to 5k naniwa SS.

and to end the off topic, here is a ikkanshi tadatsuna sujihiki, shirogami steel, natural work patina the pattern appeared when i tried to polish the patina with flitz

IMAG0083.jpg


love those blades and to clarify they are all very pure carbon steels with no alloy whatsoever, very fine grain and top notch performance at very high polish and very low angles...

end of the OT.
 
james terrio said:
"orange peel" is very common in D2, as well as some recent versions of 440C and 154CM that are not quite up to the original manufacturing standards. It has nothing to do with vanadium content or how much you polish it (CPM-3V has more than twice the V of D2, but can be taken to a very high polish with no "orange peel" look... it's not easy or fun, but it can be done). It's in the structure of the steel itself; it results from large clumps of poorly-distributed carbides. The more you polish it the more apparent it will be. Ever notice how nearly all D2 knives have a very basic satin or stonewashed finish? In part, that's why.
Click to expand...
Ok. DM
 
Thanks again guys for the explanations.

I'm going to try to polish my knife in d2 to a full orange peel finish then give it some FC acid. Hopefully it will come out nicely because that will be a lot(!) of work. A lot of work that could quickly be undone with acid. :o
 
This is the knife.

IMAG1587_zps67d36610.jpg


I'll have to do the full tang of course,but I'm not sure how. Any suggestions?

Maybe a q-tip soaked in the acid? I'd rather keep it from getting under the scales. Does FC interact with CA (super) glue?
 
several options,if you want it to look clean you'll need the etch to reach all the way to the scales or keep the ricasso polished. what i'd do is either apply carefully whith a q tip or mask the scales at the ricasso then refinish there. or you can find an adequate container put the knife securely in and fill with acid carefully until it reaches the ricasso but not yetthe scales and then polish the ricasso and spine to get it clean.

i'm affraid the etched blade and polished ricasso and spine will look weird but i'd be worried about the acid going under the scales by capillarity. dont know how it reacts with epoxy and CA as i've always avoided contact. someone who knows may chime in.
 
Right, I'm in agreement. I wonder if there is a neutralizer that could be used after treatment just in case the acid does get under the scales. Not sure, maybe baking soda? I can fill any potential gaps with CA, but I'll need to know if there will be an interaction first. If nobody knows I suppose I could CA treat a piece of wood and test it out.

Man I wish I could go back in time and use FC before I made and installed the scales. :)
 
just a general advice before someone answers regarding FC and CA/epoxy (you epoxyed the scales right ?), for revealing steel structures, the more polished the blade is the crispier the "pattern" or details will be, thats why i polished my blade up to 5k naniwa SS before etching.

baking soda neutralises FC for sure thats what i use, not sure if it will be enough if the acids creeps under the scales.
 
Etching the tang on a finished knife is asking for big problems. If you're super careful you might get away with it, but there's a good chance you'll ruin the seal and end up rebuilding the handle. It depends on the etchant and the epoxy/CA whatever... there's really only one way to find out :D

When I etch blades, I either do the entire thing before building the handle, or just etch the flats and polish the spine/tang edges.
 
james terrio said:
"orange peel" is very common in D2, as well as some recent versions of 440C and 154CM that are not quite up to the original manufacturing standards. It has nothing to do with vanadium content or how much you polish it (CPM-3V has more than twice the V of D2, but can be taken to a very high polish with no "orange peel" look... it's not easy or fun, but it can be done). It's in the structure of the steel itself; it results from large clumps of poorly-distributed carbides. The more you polish it the more apparent it will be. Ever notice how nearly all D2 knives have a very basic satin or stonewashed finish? In part, that's why.

The powder version of D2, CPM-D2, does not exhibit the orange peel look; nor do any other powder/particle metalurgy steels I've seen. This is simply due to a finer, more homogenous structure.
Click to expand...

James,
I have made about 10 culinary knives so far with the CPM-D2 and was very happy with the results as chef knives.
I did still get that orange peel look because of those "clumps of carbides" as you put it, are still there. It was not as noticeable as plain D2, But still there.
 
this discussion made me want to etch some d2 with ferric chloride.

%255BUNSET%255D.jpg


IMAG0560.jpg


looks pretty good i think, the dark blade really pops with orange g10. the blade was already close to mirror polished, it took 2x10sec on ferric chloride to get this.
 
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