Case hardening mystery

Bruce Bump

Bruce Bump

Joined
Dec 2, 1999
Messages
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I ordered 35 pounds of bone and leather charcoal from Brownells the other day. Also ordered the crucible to pack and heat the parts in. I havent done case case hardening before but have read up on the subject. There seems to be conflicting stories from people on how to do it properly to get the colors and no oxydation on the work surfaces. There is supposedly another ingredient to the mix to add the red tones. Does anybody know what the mystery stuff is or any other cool colors? Also does the crucible need to be completely air tight and how long of a soak time and temp?

I have a video on simple case hardening with casenit. It is really simple but doesnt get any colors. I gotta have those colors:cool:
 
hey Bruce I can case it but I'll be looking on for answers
in the coloring with you:confused: copper maybe just guessing :(
 
Hi,
To get the best colors use Arsenic. Just one problem, deadly poison and most of us only have one mother-in-law to get rid of.:rolleyes:
I have had good luck with a stong solution of Tri-Sodium Phosphate (TSP) in a 10 gallon bucket. You need to VIGOUROUSLY agitate this with air. I use the bubble wands from fish aquariums.
I cook the packed crucible in the back of my forge for about 2 hours at I would guess 1850 - 1950 degrees. It sits back there while I make my hooks and candle holders from mild steel. It needs to be reasonably tight. I smear a bit of satinite around the seam but I don't obsess over it. After it has cooked for the 2 hours, I QUICKLY seperate the crucible and pour the ENTIRE contents into the bucket.
Speed counts. The magic is in the air and agitation in the bucket. It really is pretty hard to get too many bubbles in there. One of these days I am going to try using oxygen/Air mix. Keith Kilby uses oxygen and gets pretty good colors. I haven't dug my torch set out of the back corner of the shop to try that yet.
Remember that Case hardening colors will fade in exposure to sunlight after a few years, so keep well waxed and cased.
My crucible is homemade. It consists of 2 pieces of thick walled pipe that are a slip fit. A plate welded on end of each and the larger piece fits on top so that gravity helps the seal around the base.
If you really get into this, for color consistency you will probably need to cook in a temp controlled furnace and start keeping track of the time/temp. Leather scraps with the charcoal seems to help. Probably something in the tanning.
If you accidentally drop the crucible in the bucket, expect steam burns.
Enjoy, Ken PS: See you at Blade
 
Ken, Thanks for the good response. I also have heard about the air bubbles helping to make better pattern and colors. I plan on buying a lawn sprinkler and useing my air compressor. The TSP is interesting. What color are you getting? I hear that a barrel of water will cool the part before it hits the bottom. For small parts I bet the 10 gallon bucket is big enough. I do have Even Heat digital ovan and can be consistant on the times and temps. I also hear the temp to be 1500 and time should be 4 hours. Does that sound right?

The gun smiths dont share info like knifesmiths do so its hard to get a good procedure from them. It seems that they want to leave out a step so I will screw it up and get discouraged. Some have a secret ingredient that will go to the grave with them. Im determined to do this so I may find my own secret with all the experimenting. That might make em mad:D
 
I was reading the first link and it says a combination of carbon, and nitrogen. Some plant grow powders/fertilizers are packed with nitrogen. The secret ingredient, cr@p!?!?!?!?!?!;) :confused:
 
Bruce you mite try Trinidad State Junior College
At one time they offered that (color case hardening)
in their gunsmithing class
 
Some plant grow powders/fertilizers are packed with nitrogen. The secret ingredient, cr@p!?!?!?!?!?!
Click to expand...

You might find plenty of cr@p where it's not expected if you mix something like ammonium nitrate fertilizer with hot crucibles and forges.
 
Sorry I can't offer much help on this one, but I do have a question of my own if any of you come across it in your research on this topic.

Henry Deringer often put a trademark finish on many of his better quality pistol barrels that looked somewhat like case hardening. Usually most of the barrel would be black, but with vivid red mottled streaks twisted around its length. Seems this process is one of those secret formulas he carried to the grave. The process may have actually been part of the blueing step; I don't know. Any ideas?

The finish on this pistol is rather worn, but if you look closely at the barrel, you can get some idea of what I'm talking about. Deringer pistol
 
Possum-Like many if not most makers of the period Deringer used Damascus twist barrels which were usually made from an iron/steel mix. The iron oxidizing at a differnt rate/level than the steel is what most likely gives the barrels that red color.
The lock plate and breech plug have been case hardened and that is why they don't show so much wear.
 
When I worked in the gun business, we used a product called Kas-e-nite(sp?). It is a liquid that you use on the metal, in conjunction with a torch. We got remarkable case colors from it, plus it was fairly easy. I would guess Brownells sells it.
 
Thanks everyone for the info and suggestions. There are sure alot of different temps. One says no more than 1325 and another says 1625 max for best penetration. I see this is going to be a real learning experiance. I will show you all my finished knife if I dont burn up the fittings.

Any more input is gladly accepted.
 
Bruce,

Leave it to you to want to learn case hardening. I too have been wondering about that.

You are among a few here that I consider my personal hero in which I hope to some long day from now aspire to.

Roger
 
Bruce,
If you figure out the case hardening I've got a couple of frizzens, however it's spelled, that I would be happy to pay!
Lynn
 
I recieved the charcoals and the crucible yesterday from Brownells. The crucible is huge and wont fit in my oven so its going back. For $73 I will make my own. At least I see how they are built. They are simple and not completely sealed just a gravity heavy lid that can be popped off quick for the quench. The instructions came with the stuff and they say 1400 deg. for 1 to 1 1/4 hours. The water needs to be aireated but not rolling bubbles at the time of quench but rather before the quench for an hour. I sprinkler in the barrel forcing air through it should suffice.

If I get confident in this thing I would be happy to do some parts but there is a warp factor to consider. I wont do any hard to replace colt or Smith and Wesson thin wall recievers ect. Hammers and sears and knife parts yeah.

I made a River Boat gamblers knife and want to post pics if this works out.

Thanks again for all the help I love You Guys!
 
Possum
The barrel on a gun that old would have been rust browned. Probably cold. I just did a Lyman Great Plains Rifle that I built from a kit. Its another one of those stupidly simple things that you can screw up a hundred different ways before you know it.
Basically you clean the metal really well and then paint on a browning solution (all I know is that its acidic) then hang the barrel somewhere hot and humid. First it turns green, then bright red rust. You card off the loose rust and paint on more solution and hang the barrel up again for about 12 hours. Keep repeating the process. The more applications you make the darker the barrel will be. I did about 12 rounds on mine and it has the appearance of being blued from a distance.
Different steels respond very differently to the solution. So there is a possibility that the streaks on your gun is because it has a damascus barrel.I had a hard time getting the tang for the hooked breech to match the barrel on my gun.
The smith might have figured out a way to heat the barrel in the process too. I have read where people got the barrel too hot neutralizing the stuff (soak in boiling water)and it gave it a mottled blue/ brown appearance. I guess the process isn't too far off from hot rust bluing. :confused:

Bruce
Sorry, but I don't know anything about the color case hardening besides the very general process which your already more than familiar with.
You might try getting in touch with the folks at www.logcabinshop.com Thats where I picked up the stuff for the plains rifle. They have gunsmithing classes there, but I think its mostly building a rifle from component parts. Emphasis on inletting the stock and finish work. They seemed pretty knowledgable and willing to help folks out though. They might point you in the right direction, or have some books on the subject.
 
thanks for the ideas, guys, but I'm certain this is not the damascus pattern showing. In the book "Peacemakers" by Wilson, there are much better pictures showing what I'm talking about. On one the pattern looks kinda like the streaks in marble. (only different color, of course) I'm guessing it is indeed some sort of finish applied with heat and chemicals.
 
taken from

The Modern Gunsmith Volume 2, Howe
1941

From this site
http://www.stevespages.com/page7d.htm

Direct Download Volume 1 Zip file
http://stevespages.com/zip/the_modern_gunsmith_v2%20-%20howe%20-%201941.zip

direct Download Volume 2 Zip file
http://stevespages.com/zip/the_modern_gunsmith_v2%20-%20howe%20-%201941.zip

the 2 page file I attached states some details on Colour case hardening taken form the second volume.

the whole chapter deals with heat treatment

It has a lot of interesting and relevant info for us.


For the cut n shoot wannabe's - volume 2 also shows the hook method of cutting rifiling
 

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Steven, Thanks for reserecting this 5 year old thread. I cant believe its still around.
I havent seen you for awile either.
Those links may be just what I have been looking for.
 
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