Case Coloring and Case Hardening

P

Paul Skvorc

Guest
Gentlemen,

I am looking for information on case coloring and case hardening. It is my understanding, that case coloring and case hardening are the same, EXCEPT that when one wants "special" coloring when hardening one uses different materials around the object being case hardened.

Please correct me where I am mistaken with regard to this/these processes.

Secondly, I have recently purchased an oven in which I will be able to temper/harden/color various metal objects. I am considering case coloring a Turk '38 receiver I have - IF it is reasonable to do so. By "reasonable", I mean:

1) Will case "coloring" ruin the "temper" of the receiver?
2) Will case "coloring" actually "improve" the temper of the receiver?
3) Is there some 'fatal' flaw with respect to trying to case color an old milsurp receiver?
4) Can I use Kasenit for case "coloring"?

What I don't know about case 'coloring' would fill volumes, so I'm 'all ears'. Please feel free to make suggestions beyond that which my limited knowledge has allowed me to ask.

Thanks,
Paul
 
Paul,
I'm not the expert on color casing, but I do know you can case harden metal with kasenite but you cannot color case with it. You have to use charcoal, bone charcoal and other ingredients to color case metal and there are all kinds of recipes for determining what colors turn out on the metal. As far as color casing old Mauser actions, it's done all the time by companies that really have the technology to control the color, hardness and especially the depth of case. Too much depth and you can make the receiver brittle and dangerous. Don't be in too big a rush to do the receivers.
 
The color case hardening I witnessed 40 years ago required heating the action red hot and quenching in a boiling bath of cyanide salts...

Not all metal is suitable for this procedure.

Sometimes the workpiece is destroyed in this process.

Cyanide fumes are very poisonous.

You have a ton of researching and experimenting to do. I would not rely on just talk forum replies.
 
If I understand correctly, most Italian Cowboy guns are Chemically colored to give a color case hardened apperance but does not actually harden the metal.

Here is an article about olor Case hardening that mentions kasenite.
http://www.thehighroad.org/archive/index.php/t-315807.html

Also Brownells sells a Color Case Hardening kit.

https://www.brownells.com/aspx/ns/store/ProductDetail.aspx?p=1026&title=COLOR CASE HARDENING KIT

Remembeer the issue with early 1903 receiver failures was believed to be caused by OVER hardening making the metal brittle.
Ted
 
It's really tricky. I played around with an electric kiln, and ANY contact with the air between the sealed steel box packed with bone and wood charcoal, and the bubbling water quench bath will ruin the colors. It has to go to 1400 deg F for about 2 hours, and be highly polished and degreased before packing. I wouldn't risk any high pressure action by myself. Too much carbon, or wrong alloy of steel, and it goes brittle. Almost ruined a Win Low Wall, cracked a Stevens Favorite action. Sub it out!
 
The best case coloring I have seen is available from Doug Turnbull Restorations at 1-585-657-6338 turnbullrestoration . com(remove spaces before and after the dot). If you are only going to do a few pieces I'd use them.

Mike Swartz
 
As Dennis Sorensen said "Sometimes the workpiece is destroyed in this process" I would do a lot more study on the subject I learned how to do it in the 60's and we used a bar-b-q with sand and charcoal, horse hooves and old saddle parts after soaking in Cyanide, I haven't tried the kits from Brownells but they would be safer then the old ways. I have seen Doug Turnbill's work it is very nice and I think very affordable.
 
Thanks to all!

I've been to Turnbull's site, and the best I can figure to case color a bolt action receiver (which he doesn't list as something he "colors" as far as I can see) is somewhere between $250 and $300. One man's ceiling is another man's floor I suppose, and while I suppose $300 is 'affordable' to some, it doesn't teach me how to do it, and, if I like it (Turnbull's doing it), I'm not going to be inclined to part with $300 every time I want to do it.

The Turk receiver only set me back $10 so I figure it is as good as it's gonna get for 'learning on'. The furnace I got has computer-controlled temperature and time, so I'll probably get Brownell's bone "charcoal" and give it a whirl. I've got some scrap I can practice on.

Thanks to all for your help. If I try it, I'll post some pictures.

Paul
 
Paul Skvorc said:
That I'll do!

Paul
Click to expand...

While you're on with Brownell's, ask them which issue of 'Gunsmith Kinks' addresses color and case hardening. I've got them all and could go look but I'm too lazy to walk down to the range.....and it's cold outside :D

al
 
THere may be a reason why Turnbull doesn't Case harden Bolt action receivers.
Maybe you should contact them and ask why. Have you ever noticed that the cylinders for revolvers aren't Color Case hardened? There surly is a reason.
 
A Danger

If you do not know exactly what alloy the Reciever is made of, or it's specific hardness, (temper), then you will have to guarde against going past the transformation range, which will start to bring it back to an annealed state. That 1400 degrees mentioned in one post seems pretty close, could possibly compromise the strength of the part. Anyway, I would never intentionally heat a finished machined high strength part to anything near 1400 degrees F temperature.

Improving the temper?? There is a wide held notion that a double temper will increase the toughness of a particular alloy, but that is a very controled proccess. Probably a little more controled than what you are going to do.

I would find some sort of chemical coloring to give the piece the cosmetic affect you are looking for........jackie
 
Butch Lambert said:
Paul,
The $10 you lose is only a small part of your concern.
Butch
Click to expand...

I agree with Butch...

Paul, I don't think you realize the action you experiment on will most likely NOT be safe to use afterwards...

The $10 you lose is not big deal, if someone builds a rifle out of it and it blows up, that is a big deal.
 
Paul Skvorc said:
Thanks to all!

I've been to Turnbull's site, and the best I can figure to case color a bolt action receiver (which he doesn't list as something he "colors" as far as I can see) is somewhere between $250 and $300. One man's ceiling is another man's floor I suppose, and while I suppose $300 is 'affordable' to some, it doesn't teach me how to do it, and, if I like it (Turnbull's doing it), I'm not going to be inclined to part with $300 every time I want to do it.

The Turk receiver only set me back $10 so I figure it is as good as it's gonna get for 'learning on'. The furnace I got has computer-controlled temperature and time, so I'll probably get Brownell's bone "charcoal" and give it a whirl. I've got some scrap I can practice on.

Thanks to all for your help. If I try it, I'll post some pictures.

Paul
Click to expand...
Get a copy of Guy Lautard's 'Machinist Bedside Reader' Vol I II or III has an article in it that describes the process. If I remember correctly it's very labor intensive. I'm not sure which volume has the article in it. All the volumes are worth owning.
 
Really, when you.......

come right down to it, the color case is only recommended for small parts; doing an entire receiver( I've seen photos of a Mauser so done), unless it will only be inside on display, is a waste of time & money. There are other ways to get the strength, but I guess you are looking for the aesthetics of the color. Has anyone told you these colors fade over time, & w/exposure to sunshine??? Old shotguns that have been hunted a bunch are often almost silver where the case used to be, & I've seen many photos of old Colt revolvers w/the cased frame that was almost totally silver, while the rest of the gun could pass for almost new in appearance. If you call the guys at Turnbull's, be sure to ask them about the durability of this finish, & ask about the pros & cons of this finish & how it fits into your plans. Turnbull's father, I believe, was a chemist that chased that technique for many years, & I think Doug himself may have carried on the search himself(picked upwhere Dad left off) to get where he is today. I would guess, too, that some raw cyanide is also placed in the package with the bone & wood charcoal. The physical aspects of the operation are not simple, either. Good luck.
 
Long time ago, I was fooling around with an old Stevens Favourite (second model) & wondered if I could "color" it. After a lot of polishing, gentle heating, filddling & splashing with cold blue & plum brown Birchwood finishes, I turned out something that didn't look half bad. Trouble is, I should have dunked it in heated petroleum jelly or something like to get in the pores & stop the rusting, so I lost all my good work in a year or so.

You could maybe try the same with any old bits you have lying around.
 
I certainly didn't imagine the interest and wide range of responses this topic has received. However, in retrospect, I should have, as the physical characteristics of receivers is a "hot" topic.

I've got "Kinks" 1 thru 4, so I'll have a look there. Good idea. Thanks.

I'll be chatting with the folks at Brownell's today, and pick their brain for what evr they are willing to reveal.

I'll give Turnbull a call too to see what 'he' says about the process for a bolt action receiver.

I am aware of the 'longevity' of case coloring. I read that there are well-established ways to mitigate the effects of aging and slow the fading process. I'm quite certain a piece of steel colored 'today' could, with a little care, be made to keep that coloring well past the end of my life.

And I'll practice with some other pieces of tool steel so I get a 'feel' for what the process, in general, entails.

That said:

I'm not one to 'walk this life in fear'. I'm 57 years old. I've been reloading since I was 16. I have all my appendages and sensory organs intact. I've never been to the emergency room as a result of my firearms activity, and more importantly for some of you, no one around me has either. I started experimenting with duplex 'smokeless' charges very early on, in spite of several warnings that "Civilization as we know it will end if you do that." I have recently started building rifles, all chambered for wildcat cartridges. Of the 5 currently built, with three more 'in the works', all are functioning quite well. I have a fairly comprehensive ballistic lab set up which includes the ability to actually measure (as opposed to guess at) chamber pressure. I have a multi-disciplinary Ph.D. in Physics, Electrical Engineering and Fisheries Science, so I am at least trained, in how to properly conduct experiments.

I mention the above with some reticence because I am totally unimpressed by "credentials". Credentials WAYtoo often cited in order to "win an argument". I hate that. Credentials are meaningless for "making a point". If one's arguments can't stand on their own merits, all the credentials in the world don't make the argument valid. I chose to mention them, because I was getting the impresson that several that have offered their opinions here - all I genuinely appreciate - were 'concerned' that I was incapable of conducting this particular process safely. In that case, citing my "credentials" is relevant.

I will continue to pursue this matter until 1) I find some reason to stop, or 2) I try it.

Thanks for all the info and suggestions. Please don't stop offering them.

I'll keep you posted.

Thanks,
Paul
 
Credentials

There has always been a divide between those with recognized credentials in a given subject and those who lack the formal education, and base ideas on what they have experienced. While I am a student of "real world" experience, I never discount the value of those who have the education, and hence the credentials, to evaluate any given circumstance.

I own a Machine Shop, where we do Marine Repair work. This involves general machine shop work as well as the repair and re-conditioning of parts that can be salvaged for re-use.

Quite often, I deal with Marine Engineers who design and build vessels and the machinery involved. It is not uncommon for a customer to send us a design from a Marine Engineer to get our input, based on what we see in the actual application of designs when they are subjected to the rigors of everyday abuse.

However, anything we choose to change will have to be run back by the design engineer, because he DOES hold the credentials that recognize him as the true authority in the matter.

As for myself, I have a lot of general knowledge about a lot of things. A lifetime of experience has endowed me with the oportunity to gain this knowledge. But, when it is all said and done, I am nothing but a Machinist who happens to own a business along with two other Brothers. That in no way makes me qualifyed to give the final say-so on criticle areas of design that must be certified my one who is recocognized by the "powers that be" to
put the final approval on any design concept.

I value and respect those who have taken the time and put forth the effort to aquire the formal education that is required to gain the "credentials" that allows them to be an authority on a subject.........jackie
 
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