Colored damascus

[jdm61]

I have seen a number of folks coloring mosaic damascus and getting blue and red colors. How do they do that?

 

[Darrin Sanders]

Either by heat or by Nitre bluing. There may also be other ways that I'm not aware of. I've seen simple mild (1018) steel polished and heated to a beautiful blue. I've been wanting to try it but haven't had a chance yet.

 

[Augus7us]

I've wondered about this myself. Some knives its obvious they just heat blued it or used something to darken it like gun blue. But then I see a lot of art knives, like some from Michael Walker and Bertie Rietveld for example, where conventional wisdom does not seem to apply.

Walker has some folders that have blades where half of it is a very even bright blue as if he had it anodized like you would aluminum. I would really like to know how these guys are achieving this.

-Clint

 

[Frank Niro]

Some metals with steel in their make up will color in reds, yellows, purples, and browns. If the piece is a mosaic Damascus and there is a mix that might show more than one color, it will require care to catch more than one color. I use a spatula made from stainless. I heat color most of the Damascus I use and have done so for probably mnore than 20 years.
Frank

 

[Stacy E. Apelt - Bladesmith]

I made a nitre bluing pot that is nothing more than a simple low temp salt pot. Many folks use a hot plate and a can or pan of nitre bluing salts. BTW, it is "niter" to many people. The salts are available from Brownell's and other knife and gun chemical suppliers. IIRC, HTT&R carries them, too.

Be aware that whatever the method and color - it is only a surface effect. It will immediately sand off and wear off with use. That said, nothing make people pick up a blade on the table faster than it being peacock blue. For the same reason, many damascus suppliers bake the final billets at a temperature to give them colors, or use a nitre pot, to make the billets look better to the buyer.

 

[Karl B. Andersen]

Be aware that whatever the method and color - it is only a surface effect. It will immediately sand off and wear off with use.

That was the first bluing effect I tried - at a bit of an expense - about '98-'99, until I discovered that with a simple aggressive rubbing with my thumb it would come off. It looked cool but was pretty worthless for any knife that will see use.

 

[jdm61]

Well, there is that. But you have to ask how many of these fancy colored knives will actually see use? I'm still wondering how they get the red colors.
Karl, on a related note, what kind of surface "finish" do you get with your hot bluing method? This may not be correct, but I have read that with the old traditional rust bluing, you tend to get a very fine "satin finish" no matter what.

That was the first bluing effect I tried - at a bit of an expense - about '98-'99, until I discovered that with a simple aggressive rubbing with my thumb it would come off. It looked cool but was pretty worthless for any knife that will see use.

 

[Karl B. Andersen]

Well, there is that. But you have to ask how many of these fancy colored knives will actually see use? I'm still wondering how they get the red colors.
Karl, on a related note, what kind of surface "finish" do you get with your hot bluing method? This may not be correct, but I have read that with the old traditional rust bluing, you tend to get a very fine "satin finish" no matter what.

My hot bluing is the exact same process used by the firearm industry for millions of guns every year.
My surface finish is determined by how I finish the steel before bluing - satin, etched, mirror polish, etc.
I'm not sure this answers your question.

 

[Stacy E. Apelt - Bladesmith]

Hot bluing will last longer against wear, but eventually will also wear with use ... and immediately with any sharpening or sanding. It requires equipment and training to do right. It is also very dangerous if the safety rules are not followed.


Here is a link that may help people understand the salt coloring process:
http://www.knifeblog.com/coloring-damascus-how-its-done/

 

[Karl B. Andersen]

[video=youtube;AX6E_K_DMxg]https://www.youtube.com/watch?v=AX6E_K_DMxg[/video]