Bluing a knife blade?

May 31, 1999
Has anyone ever successfully (or unsuccessfully, for that matter) blued their knife blade? As well, what does it offer in terms of rust-resistance, etc? Thanks,

"Earth has its boundaries, but human stupidity is limitless."
I used to do a straight cold-blue on several of my knives, but now I use a subsurface cold-blue patina on two series. It doesn't prevent rust altogether, but it does help prevent the rust from penetrating deeply into the grain, which is the real problem so far as blade strength is concerned.

Sean Perkins
A thread on this very topic has been going on on rec.knives for a few days. You might try a little Deja News.

Thank you, but I actually posted this after reading that specific thread. It didn't really answer any of my questions, so I decided to try it out here.
Besides, I was wondering if anyone has ever blued a (factory) knife, such as an Endura or AFCK..

Nowadays, I try to aviod Dejanews as much as possible.. crappy new layout.

"Earth has its boundaries, but human stupidity is limitless
I'm curious as to the differences in bluing a "stainless" versus a "carbon" steel. I've used a cold-bluing compound that will not touch stainless but works reasonably well on carbon steels. I'd almost think that you couldn't even hot-blue stainless, but SOG seems to manage with the very corrosion resistant 440A.

At any rate it's a classy finish that substantially helps rust-resistance (especially a nicely done hot-bluing) and I wish we saw more of it, rather than coatings that wear easily or bead-blasting that actually invites corrosion. I think the reason we don't see more is that it requires a high degree of polish, whereas coatings and bead-blasting can actually mask a rough finish.


(Why else would a bear want a pocket?)

That's actually the basis of my question; I'm thinking of getting rid of the epoxy coating on my Recon Tanto and bluing it. I'm not a fan of that coating, since it gradually disappears every time I cut something with it, and I don't think it acts the same way as the Black-T coating that Benchmade uses.

"Earth has its boundaries, but human stupidity is limitless."
I was interested in this very thing, but the back of the bottle said you can't blue stainless steels. But I am going to try it on a Freer knife I have which is made from a file.
Bluing is basically a controlled form of rust. If it won't rust, it won't least with conventional blues. IIRC, Brownell's may have something that does blue stainless.
I've been wanting to try this with my old CS Trailmaster. I don't have any blued pistols; will the bluing scratch to reveal silver underneath? Is it pretty deep? Can one blue and reblue to achieve a desired darkness? Thanks.

My experience is that bluing provides rather minimal rust protection (if any). It does hide rust somewhat. It looks cool and it has some value on a commando dagger. It seems like mostly an aesthetic thing.
Can you Cold Blue Cold Steel's Carbon V?

I mean, if I went around saying I was an Emperor because some
moistened bint had lobbed a scimitar at me, people would put me away!

You can cold blue carbon V, just be sure to heat the blade with boiling water before hand. Also be sure to thoroughly remove all oils and contaminants on the blade before hand, otherwise it will streak. Bluing stainless steel is very expensive as it reqires special chemicals and special equipment in a process simmilar to hot tank bluing.
A lot of the reason I hate stainless steel is it can't be blued. It can be coated with bake-on teflon paint, Brownells sells it, but it's paint, not blue.

It's been a while since I've posted about bluing.... I like to do a mottled finish, applying it with Q-tips or an artist's brush. Sometimes it comes out not looking so great -- then I just polish it off and start over. It's fragile and easy to polish off when it's fresh. It hardens into a more durable finish in a few days. It can still scratch and wear off and it isn't really great rust prevention, but it's easy to touch up and it's beautiful.

I like Formula 44/40 better than any of the others I've tried. They all have the same active ingredient, selenic acid (cold blues, that is; hot blues are different) but Formula 44/40 works fast and doesn't require as fanatic a degreasing as most of them.

You can use a wax resist with cold blue -- coat the blade with wax and scratch your name in it or an immortal work of art -- I shouldn't say immortal; it'll get scratched up and wear if you use the knife ... you can always polish it off and make a new work of art, though.

-Cougar Allen :{)

Don't waste your time. The bluing will scratch and wear off like any other "coating" you use. Faster than many in fact. Just look at what "holster wear" inside a relatively soft leather holster will do to the finish of a blued gun.

The other comment is quite correct. Bluing is controlled rusting. If it don't rust, it don't blue. As most of us know stainless steel is rust resistant not rust proof so some bluing will take to some degree. This will differ depending on the steel encountered.

Have you considered black electroless nickel plating? Damn strong, damn smooth and looks lovely too.
Well, yeah, it doesn't last forever; it doesn't even last as long as other coatings, but unlike other coatings it only takes a minute to touch up.

-Cougar Allen :{)
I have managed to darken ATS34 a little by letting it soak in some battery acid for a while. It has a nice non-reflective grey color to it and it does not scratch when I hit it with steel wool. I have been told that ferric chloride does about the same thing. I was just experimenting when I did mine and your milage may vary. IT ain't blued, but at least it is darkened with out being bead blasted. And it does look good with the OD green canvas micarta grips..

When I inquired at the local gunsmiths shop whether or not it could be blued, they said that it could, but that they, and probably no-one else in AK had th stuff to do it.


It is not a matter of whether or not you are paranoid, it is a matter of whether or not you are paranoid enough.