Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Blackening Steel
elementcollector1
International Hazard
*****




Posts: 2679
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

[*] posted on 16-6-2014 at 06:26
Blackening Steel


What would be a good way to do this at RT for long-lasting results? The reason I can't use a hot bath is because the steel has industrial-strength glue on it, and I don't want to mess with the composition of that.



Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Ge
View user's profile View All Posts By User
Burner
Hazard to Others
***




Posts: 100
Registered: 28-3-2014
Member Is Offline

Mood: No Mood

[*] posted on 16-6-2014 at 07:07


There are a number of commercial solutions for this (ex. http://www.amazon.com/RT-S25-blackening-concentrate-bluing-s...). If the item is something you are willing to use for experimentation I suggest that you find a copy of the Metal Finishing Handbook. If I remember correctly they had a few recipes in there that you might find useful.
View user's profile View All Posts By User
elementcollector1
International Hazard
*****




Posts: 2679
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

[*] posted on 16-6-2014 at 10:56


It's not for experimentation; this is intended to be the finished product.
Plus, that product doesn't seem legit...




Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Ge
View user's profile View All Posts By User
Burner
Hazard to Others
***




Posts: 100
Registered: 28-3-2014
Member Is Offline

Mood: No Mood

[*] posted on 16-6-2014 at 11:29


Quote: Originally posted by elementcollector1  

Plus, that product doesn't seem legit...


Why do you say that? I suggest that you google the product before you clamp down hard. The company that makes it has been in business a long time and you will find many positive reviews on the web. Of course you may not trust them. That is your call.

[Edited on 16-6-2014 by Burner]
View user's profile View All Posts By User
m1tanker78
International Hazard
*****




Posts: 685
Registered: 5-1-2011
Member Is Offline

Mood: No Mood

[*] posted on 16-6-2014 at 16:00


Would the glue withstand a dip in strong acid? Can you re-glue the pieces if needed? Do you roughly know what the alloy composition is? Industrial strength.... as in liquid nails or some super secret proprietary stuff???

If you're unwilling or unable to experiment with the item, you might try calling around to antique shops and/or gun shops. Usually, the more mom-and-pop-ish, the better - to a point.

Oh, and what sort of abrasion resistance are you aiming for here? Have you considered a durable spray-on finish?

Tank




Chemical CURIOSITY KILLED THE CATalyst.
View user's profile View All Posts By User
Texium
Administrator
********




Posts: 3424
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline

Mood: Triturated

[*] posted on 16-6-2014 at 16:08


I wonder what that solution contains. Possibly some copper salts, based on the blue color?
If that's all, it could be cheaper to make yourself rather than buying it at that price. Of course, there's probably other ingredients, and the concentration would be important too.




Come check out the Official Sciencemadness Wiki
They're not really active right now, but here's my YouTube channel and my blog.
View user's profile Visit user's homepage View All Posts By User
IrC
International Hazard
*****




Posts: 2710
Registered: 7-3-2005
Location: Eureka
Member Is Offline

Mood: Discovering

[*] posted on 16-6-2014 at 16:28


Quote: Originally posted by zts16  
I wonder what that solution contains. Possibly some copper salts, based on the blue color?
If that's all, it could be cheaper to make yourself rather than buying it at that price. Of course, there's probably other ingredients, and the concentration would be important too.


Copper-Selenium compounds (varying recipes abound) for cold bluing. Rubs off too easily, and must be kept coated with a waxy-oily mix. Mid temp bluing is still in the 220 degree F range. Only hot bluing gives a decent result. A boiling hot 300 F mix of Sodium Hydroxide, Nitrate, and Nitrite. Mixture must be made outside or in fume hood as Ammonia gas is given off for the first while when preparing the solution. If cold working is mandatory no way will you make your own anywhere nearly as cheap as the bottle you can buy at Walmart or various other places, identical to the link already given that EC1 didn't seem to like. Whats not to like? It's either that or go the hot blue route.

http://en.wikipedia.org/wiki/Black_oxide

http://www.smokstak.com/forum/showthread.php?t=68321




"Science is the belief in the ignorance of the experts" Richard Feynman
View user's profile View All Posts By User
bobm4360
Hazard to Self
**




Posts: 56
Registered: 18-4-2011
Location: On a wretched little island.
Member Is Offline

Mood: No Mood

[*] posted on 16-6-2014 at 20:46


Rust blue is as permanent as hot blue, just labor intensive!!! If the piece will stand 100 deg. C., you lightly rust the part, remove the rust with steel wool or a SOFT wire brush, boil to turn the rust black, and repeat as necessary. There are slightly less formulae for rust bluing than there are known stars in the universe and most of them work. Otherwise, I often use Birchwood-Casey cold blue cream, and heat the part in running hot water as hot as I can stand, and swab it on. Usually takes 2 or 3 coats. Wear latex or nitrile gloves!
View user's profile View All Posts By User
aga
Forum Drunkard
*****




Posts: 7030
Registered: 25-3-2014
Member Is Offline


[*] posted on 17-6-2014 at 12:29


you can use a 'tampon' with a weak acid (not sure which) and pass a current thru it and the steel.

the tampon should be a bag of some sort with cotton or rockwool in it.
The tampon is where the acid is, and where you connect one electrode.
Other electrode goes on the steel.

Cold process and you can choose which bits go black.

[Edited on 17-6-2014 by aga]




View user's profile View All Posts By User
wallschem
Harmless
*




Posts: 6
Registered: 17-11-2010
Member Is Offline

Mood: No Mood

[*] posted on 17-6-2014 at 19:41


I use cold blueing to protect from rust the spring of the mechanism I manufacture, and I get very good results cleaning the spring with iso propanol, then in a 50ml of wather add 10g of Selenium oxide, 15ml of Nitric acid and 10g of Cupper sulfate. And it takes 3 seconds to get a very nice blueing, I have a video of the making of the mechanism and the steps to make the cold blueing solution.

http://m.youtube.com/watch?v=t9V_b8ANCGg
View user's profile View All Posts By User
franklyn
International Hazard
*****




Posts: 3027
Registered: 30-5-2006
Location: Da Big Apple
Member Is Offline

Mood: No Mood

[*] posted on 21-6-2014 at 04:59
Read & view the lower part here _


www.sciencemadness.org/talk/viewthread.php?tid=24480#pid2864...

Baking in an oven will set the finish. The finish shows the
level of polish of the bare metal. A dull finish will look dull.
A mirror finish will appear as such.

.
View user's profile View All Posts By User

  Go To Top