Remove CASE hardened color.

[flashpanner]

Lime-away works too.
You can also use it for removing water deposits from the sink as well!

 

[Russ T Frizzen]

Well it does harden the steel alright, but it doesn't look much like the the old fashioned bone charcoal method does.

 

[Trench]

I'd love to post pics, but I haven't figured out how to do it yet. Where the heck is that "photo bucket"? If anyone wants to PT me some instructions, that would be great.

 

[44-henry]

The cyanide process was used by some arms companies in the 1800's and is an appropriate finish for these guns, it just wasn't used by Colt. If the metal is properly prepared it is actually quite attractive, but it does give a different look from that of bone and charcoal.

Somewhere on this board I have a post where I show the process of bone and charcoal, which I do quite a bit of, I probably will never do the cyanide because of the risk factor.

 

[paulvallandigham]

The process Oscar Gaddy wrote about is called BONE CHARCOAL Case Hardening, and the Charcoal is made from reducing powdered bone. Its benefit its that it makes a finer charcoal, than what is produced from wood products.

I only point this out to make sure people understand you are dealing with ONE product, Bone Charcoal, and not two separate products, Bone, and Charcoal. Bone Charcoal can be purchased from Chemical Supply companies.

 

[Trench]

Okay, I figured out the photo thing. This is how it looked coming straight out of the toilet bowl cleaner.

 

[dallas10c]

that's the look I want also...thanks

 

[44-henry]

Paul, Bone charcoal is a part of the process but wood charcoal is also used along with it. There is no difference between the size of the charcoal in either bone or wood, both can be made equally fine. There is a difference in the chemical composition of the bone charcoal and it is a necessary element of the process because of this.

You could probably use dead grass to caseharden low carbon steel, but you also probably wouldn't get good colors with it. I've made my own charcoal, but now I have settled on the stuff that Brownells sells. Different ratios of wood charcoal to bone charcoal changes the colors produced. I've gotten nice results with 50/50 ratios, but I've worked with others also.

I've also found that temperature and quenching technique are important elements in the equation. I typically have between 30-40 students perform this process on their steam engine parts each year so I get lots of opportunity to experiment with different techniques.

I have heard of parts cracking when going into the quench and have never had it happen. I do anneal everything before I do the polish and make sure everything is blocked properly to help prevent warpage, breakage has never been an issue. I've talked to others who do a lot of actions and most admit to annealing beforehand which tends to suggest to me that this is an important step in the process. I also bring the parts up to 400 degrees after the casehardening operation to remove stresses in the material and it also helps to enhance the colors on the finished part.

 

[Dphar]

I own a Pedersoli Frontier rifle. The lock has that ugly CASE hardened mottled color. What would be the easiest way to remove this color and get the lock back to it's original metal?

Chrome polish. Or other very fine abrasive. Will make it look like it actually silvered out or was worn. Acid makes it look like it was removed with acid.

Dan

 

[paulvallandigham]

Alexander: I am sure you have read Dr. Oscar Gaddy's articles on Bone Charcoal Case hardening in the Double Gun Journal. He wrote the articles, and submitted them for publication because he didn't want the process lost again. It took him years to figure out the original technique, because the old masters took the formulas to their graves. He found the few published "formulas" were missing steps or actually had misleading information in them. He consulted Professors of Chemistry and Metallurgy to unravel the secrets, and find out where missing steps needed to be filled in. One of the things he found left out was the need to soften the water used to quench by aerating it for at least 1/2 hour before its is used. Oscar used a compressor to put air into the bottom of his water tank to do that. Oscar used Distilled water, also, finding it gave more consistent colors than did tap water, even though the water in Urbana is considered the best in the world, in quality. ( I can tell you that only because Urbana is the home of the University of Illinois, and draws students and faculty from more than 110 different countries from all over the world, and, obviously, people from all across the USA. They are the ones who tell the natives how good the water is.)

 

[Zonie]

I wonder if Cyanide made Hardened Criminals?
I know in the good old days they tried it on a number of them. :rotf:

 

[paulvallandigham]

Zonie: I am sure it did, about 2 hours after death, when Rigor Mortis set in! :rotf: :hatsoff:

 

[dallas10c]

My thanks to Trench who showed what his looked like after REMOVING the color case hardening, which was what his original question. Somehow it morphed into how to DO case hardening...funny how things change from the original question?!

 

[Randy MacInnes]

Trench I'm glad this worked for you without a lot of cost. I believe you can take some 0000 steel wool to it now and maybe able to buff it up a little. It's hard to see in the photo's and what type of finish you are looking for. I hope this helped you if you need anything else you can PM me.