Darkening Stainless Steels

T

timogranzotti

Joined
Jan 22, 2008
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I recently ordered a Predator WSK and was searching for methods of darkening the 440C Stainless Steel blade. I was looking for a method or acid that would be
the least toxic as I will be also using the knife for gutting, skinning, etc. but durable enough for heavy chopping, drawing, etc. Any Ideas? Thanx!
 
Gun-kote sounds solid. I also heard of things like apple cider vinegar or leaving the blade in a potato and chilling it, but for high carbon steels, dunno about the stainless... Thanx for the reply!
 
Not sure what he did but...

Butch Harner (of Harnerknives.com) did this paring knife for me in S30V.

ButchParing005-1.jpg
 
It's just not "finished". On most knives, the steel looks like that after heat treat, then it is satined. That one just wasn't except for the edge grind. It's a "rustic finish" so to speak.
Which is one of my favorite knife finishes BTW!
 
would there be anything that I could brush on that would 'eat' the blade topically and give it that look post-production?
 
Now, Radio Shack sells an etchant for etching copper PC electronic boards. I've used it to make small IR flasher and variable DC power boards, but I can't think of it's name right now! It's a ferro-something or other. Well, anyway, it might work on stainless..... I should dig out my bottle and try it on a Mora.
 
Ferric chloride? Yup, just googled it, that's what it is. Often referred to on the Maker's Forum as FC. However, I don't think it's NEARLY strong enough as an acid to do any serious "harm" to a good stainless.
 
Ferric chloride will etch stainless, but the surface will still be silver with a frosty appearance-like fine sandblasting. The only way to darken 440 is by painting it with a surface treatment. Any surface treatment will wear off quickly. I can think of no reason to want stainless steel any color other than it's natural color.
 
Interesting... Well, it comes down to a concern about glare when out in the field, both in my eyes and the eyes of prey; surface coats kinda sound like a waste of time; could ferric acid have a greater effect if I do multiple applications, or does it reach only to a point?
 
It will only frost the blade. Blade will still be silver. Bead blasting would work better.
 
Thanx for the help! I think I might bead-blast it then...would there be a psi you could recommend? I was looking at a cheap blaster that worked at 90 psi.
 
I used some naval jelly on some stainless to find it etches some types pretty well. It doesn't come out black, but a matte non reflective gray, which may be a good base for some kind of coating.

I used naval jelly on the handle of a Kershaw Chive to get rid of the slippery bead blast finish, giving it a significantly grippier, dry feel, almost like an old blackboard.
 
I dug up this old thread on what I did.

Corrosion has not been a problem with either knife. The Mora even survived several weeks living outside in my back yard getting a nightly spray from the sprinkler with no corrosion at all.
 
I've used ferric choride on hardened 440A and a benchmade pocket clip, which I'm assuming was 420j2 or 300 series. In both cases the ferric gave both a dark matte finish alot like black phosphate in appearance. I actually let the benchmade clip soak for a while and it came out looking like a rough blackened beadblast. Can't remember the concentrations I used but I think the clip was something like 50/50.
 
timogranzotti said:
Thanx for the help! I think I might bead-blast it then...would there be a psi you could recommend? I was looking at a cheap blaster that worked at 90 psi.
Click to expand...


90 is fine.....
If you have some blasting equipment, i can give you some media just for the cost of shipping, i have about 3 tons so just name your amount. It is used stuff that we use so many times then throw it out, however when we toss it, it is a very fine powder that leaves a nice silky smooth satin finish without the typical "sand blast pits" that will for sure take that "shine or glare" out
 
Thanks Shecky I'll try it! The image results on the old thread really worked out and looked good. Just curious, what's the hardness of the Mora?
 
fastcamo said:
90 is fine.....
If you have some blasting equipment, i can give you some media just for the cost of shipping, i have about 3 tons so just name your amount. It is used stuff that we use so many times then throw it out, however when we toss it, it is a very fine powder that leaves a nice silky smooth satin finish without the typical "sand blast pits" that will for sure take that "shine or glare" out
Click to expand...


Good deal fastcamo, I'll keep you in mind if I revert to Bead-Blasting. I think I'll try the naval jelly option first...
 
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