U. S. Arsenal color-case methods?

[Kevin Tinny]

Hello:

Perhaps our experts will share their knowledge about the process used at Springfield and Harpers Ferry to harden lock plates, hammers, etc.

From my very limited experience and some research it appears to me that at least the coloration and hues of U.S. arsenal hardening are significantly less vivid than the Colt Peracemaker/Turnbull versions. I have been told that the arsenal version is almost a washed out grayish with little contrast or has the appearance of "gasoline floating on water".

So, if anyone can help, please share why the arsenal version appears less vivid and if known, how it was achieved.

Many thanks,
Kevin Tinny
42nd NY

[Bruce Cobb 1723V]

There are very few originals, as issued, that have never seen the light of day. The daylight is what fades the case color.

[John Holland]

First of all, there is a world of difference between "Case Hardening" and "Case Coloring". Case hardening was done to actually harden the surface of the material, with no regard as to what it looked like. Which in most instances the finish is a dull gray. Not only was it not attractive to look at, it wasn't intended to be so either. It was a process to accomplish an end result, which was to harden the surface of the material from 0.015" to 0.030" deep. You have to remember in the time frame of the Civil War they were working mostly with Iron, or Malleable Cast Iron, so it required a case hardening process to give it some durability.

Today they are working with Steel Alloys which go through a heat treating process first, then the commercial grade products are "Case Colored" to make them visually attractive to the potential customer.

In my career as a Tool & Die Maker, for many years I had to manually case harden low carbon die steels which would weigh from 10 to 25 pounds apiece. This was accomplished by heating the steel in an oven to about 1700F and then quenching it in a Sodium Cyanide bath. After that treatment it was immediately quenched in a water/oil bath to wash off all the Cyanide. The end result was a dull gray color with maybe a few traces of faint oil colors. Another side effect was every time we did that we were breathing in the vaporized Cyanide fumes. I am firmly convinced this is one of the underlying causes of some of my medical issues today.

[John Bly]

John is correct in that hardening of parts in the national armories was for durability and not appearance. Any colors other than gray was a side effect. Commercial arms needed to be attractive so the hardening process produced more colors. I can't tell you what the individual processes were but they all involved carbon producing materials such as bone meal, leather and charcoal. Widespread cyanide use began in the 19th century I believe. It produces good case hardening but not necessarily very good colors. Bone meal and leather are still use for colors.

John, I worked with cyanide and was well informed on safety with it. Hydrogen cyanide locks CO molecules onto hemoglobin and won't allow it to carry oxygen causing suffocation. You either get enough of it to kill you or you recover fully when given the antidote or your body makes new hemoglobin. I don't think it has lasting effects.

[John Holland]

Thanks, John, for the additional info on the Cyanide vapors I had breathed in. We also worked with a lot of carcinogens which weren't identified as such until many years later. I know by the time I retired there were a lot of chemicals we weren't allowed to use anymore. It was different times a half century ago and I thank God I am still here!

[ms3635v]

For what it's worth, I have an Colt rifle-musket that appears to have never been fired, with the exception of proofing the barrel. The stampings on the metal and the cartouches are extremely crisp, so I am not sure if had been issued or not, but it is bright steel with no signs of color case hardening or case coloring. The musket had been in private hands for many years and it shows no signs of attempts to polish the metal. I do not know much about Colt's manufacturing process during the war years, so I don't want to pass any information on that may be erroneous or incorrect. All I can say about my Colt is it looks factory new.

[Curt]

Hallo!

I am at great disadvantage as 95% of my books are boxed and in storage for coming up a two year never-ending house remodeling "project."

:( :(

But I will throw it out, right or wrong. IRRC, the process was "carburizing" case-hardening where the parts were oven heated and then quenched in oil over water to impart the carbon (provided by the oil) in the surface with the water producing the
"waves" or spots of mild color apart from gray.

One problem with the whole picture is that there appears to be a gap in our knowledge as the armories do not appear to have been consistent with how the "Springfields" left the factory. Meaning, one finds the heat hardened quenched and blackened say rear sights black on say a M1861, bit sometimes bright. Sometimes on really minty guns the screws were left "heat" blue rather than being polished bright. Internal lock parts are heat treated blue still, others bright.

Last but not least, are the colored lock plates of the the M1863 found on some but bright on most.

http://i4.photobucket.com/albums/y104/Michael1787/M187172Springfield.jpg (http://s4.photobucket.com/user/Michael1787/media/M187172Springfield.jpg.html)

Curt

[John Bly]

Here are pictures of two near mint condition Maynards with totally different color patterns. Same process??? It would seem that something was done differently.

[John Holland]

Regardless of the topic at hand, those are a couple of beautiful Maynards!

[RaiderANV]

I have five mint Maynard's which span serial numbers as low as 21XX up o 27,1XX and all are prettier then the top one in your posting. I've examined couple 100 more minty ones and never seen one like your bottom picture. Maynard actually imported "Dutch steel" to build his guns which I imagine steel would take a lot better color also.

[John Bly]

I don't own those Maynards, I got the pictures on the internet. I just thought the differences were striking. It has been stated that Maynard used "Norway iron" in their guns. Norway iron is somewhat of a misnomer as most steel labeled Norway iron was Swedish steel. Norway is not known as a steel producer whereas Sweden is. Norway iron is not mentioned in ledgers from Mass Arms. They bought most of their steel from Arcade Malleable Iron Works. They bought barrel steel, stubb steel, cast steel, iron rod, decarbonized steel and others but no mention of Norway steel or Dutch steel. There was a firm called Norway Iron Works in the northeast in the 19th century but no mention of purchases from them. The iron in Maynard frames is really pretty crappy stuff with lots of slag inclusions. The barrels seem to be good sound steel.

[John Holland]

Great information, John, thank you for sharing it with us Maynard enthusiasts!

[Gary/CO]

Can’t help as I’m still learning about color case hardening. I’ve only done it once and it was without cyanide. Canadian John Seim has a book out on color case hardening.

[Kevin Tinny]

Hello:

Here is something interesting that I accidentally observed since starting this Thread in March, 2017:

The original question was posed because it seemed that all four of my original locks and hammers were almost devoid of colors. Each of them is in especially nice, but used appearance and on a Nixon built rifle with original parts, Dunlap wood and either a Hoyt or Whitacre barrel.

I agree with Bruce Cobb that sunlight eventually fades traditional bone and charcoal hardening. This is common knowledge on the Shiloh Sharps Rifle Forum and in Shiloh's FAQ's.

What I found about six months ago, when removing a hammer from an 1841 lock was a patch of original coloration on the lock plate UNDER the hammer. I did not take a photo, but could sometime soon. Anyway, the coloration is as described above by the gray-beards, namely subdued gray, with some shading of almost charcoal gray and a bit of almost black. No yellows, reds or blues, that are more common today.

All the best,
Kevin Tinny

[John Holland]

Well said Kevin, I have also experienced the same, so called, phenomena!

[Southron Sr.]

FWIW....The late Bill Edwards (who wrote "Civil War Guns") told me that back in the 1950's he opened a wooden box of Springfield spare parts that had been sealed since they had left Springfield Armory back in the 1860's.

That the Springfield lockplates and hammers had bright "case coloring." He attributed this to the fact that the box they came in had been sealed for 90 odd years back then. i.e., there was no sunlight in the box to fade the colors of the casehardening.

[gmkmd]

My understanding was that in the 1800's, the vibrant colors imparted during case-hardening were simply a pleasant by-product of the techniques used at that time, not a specific goal. More modern and expedient techniques of case-hardening achieve the same hardening result, but without imparting the colors. Hence in modern literature, we have to specify "color case-hardening" versus "case-hardening", while in the original 19th century literature they don't make that distinction.

[Maillemaker]

Has anyone been able to document the actual historical process used? I thought it involved bone meal?

I case harden with scraps of leather.

Steve