doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Case Coloring

Yes prolonged exposure to UV will have a negative impact. HOWEVER, we are talking years. Why anyone would not at least use a case is beyond me. Case coloring will fade because of handling. Why any idiot would put naval jelly on a new gun is beyond me. Naval Jelly is infused with phosphoric acid!

Those "Texas" guns had obviously been heavily used and handled.

That "pewter" appearance can be achieved after a gun has been hardened by removing the case colors with toilet bowl cleaner aka dilute Hydrochloric acid. It is called a French finish. Ken Hurst uses that "trick". Or simply have the metal recase hardened using a product like Kasenit.

Pete

Don't confuse Cyanide processing with Charcoal pack processing.
I'd love it if someone would just make a PE showing .5 in thick pieces case hardened, representative samples sliced and polished, and then re-cased at an agreed apon temperature for the purpose of coloring. Finishing with slice and polish, and measuring of the case after round 2. Just think how boring the vintage machinery and gun sites would then be.

That would tell us more than we wanted to know.
I read an additional article from way back about japanning the pieces to shield them when re-coloring. A paint on protectant might be much easier than Cu plating for round 2.

Latest guys to get poisoned around here were stripping stolen X-ray film in a garage. Some others were rendering the gold from recycled computer parts.

Ed and Pete thanks for the pointers. A friend has an old H&H that lost its case color, the surface is an even grey patina that gives that shotgun a lot of character. I will try the weak acid on an old piece and see what happens.

I have used naval jelly to remove bluing before but never on case colors. Will give that a try too and see how it works.

Clapper Zapper posted

Pretty common currency in Birmingham around forty years ago; we used a cyanide copper bath. I'm not exactly sure what the following heat treat process was, that wasn't our bag, but it wouldn't have been charcoal; almost certainly gas carburisation. Where edge nodulation occurred the copper had to be machined back to a datum surface, so there was a lot of toing and froing which made it very expensive and thus suitable only for "special" high value parts.

Usually applied to seriously big parts that needed crane hoists, from memory the deposit was around .050", but we went over that quite a bit on occasion.

Eug

PeteM, or anyone, can you explain the sunlight fading mechanism? I can't find anything about the "stuff" that makes up the CC film that "should" be photoreactive. I had a long talk with Dr. Gaddy about this and his opinion was it is not photoreactive. I. too , have heard often CC will fade in sunlight, but as of now, I'm a skeptic.

DDA

I can't think of any reason why the carbon would leave the case and participate in the colors. The colors, AIU, involve oxides of iron and other stuff in the quench, not carbon.

DDA

Don,

I seem to remember a long discussion about this that took place here many years ago. I can't find the post. Apparently I did not save the thread in my archives.

So, I guess I was repeating what I can't back up. After a web search about the effects of UV, I cannot justify the notion of fading having an impact on case colors.

Perhaps some one with practical experience can help.

Pete

Years ago on a thread on this BBS, I brought up the fact that UV fades the case colors, and many key board engineers argued as many normally do and disagreed vehemently .......It is common knowledge with people who have practical experience with case colors as guns are brought in that are faded from years of UV exposure and without normal handling wear/carry patterns on the bottom of the receivers, this fading does occur normally from both natural sun light and indoor florescent lighting.

Ken Hurst finally chimed in on that same thread and agreed also, noting that Colt, where he worked for years as an engraver, had a problem with the UV from florescent lighting fading the case colors in their show room on new guns , so Colt would remove and replace the faded CCH guns every year, which were faded on the UV exposed upper side only and they would re-case them........

But many of you still argued endlessly because you couldn't find some Phd's paper on the internet referencing this subject......but I can tell you for a fact that UV fades case colors......and it is well known with people who work with CCH-----NO, it's not overnight, but UV fades case colors.......the old glass doors on wood gun cabinets were famous for reflecting sunlight and fading case colors on either the morning or afternoon sunlit sides only......

As Wonko says, have a day.......

Doug,

Thank you so much. You confirmed that my memory is not yet achieved Swiss cheese status. I found the thread, Deja Vu all over again....

http://www.doublegunshop.com/forums/ubbt...true#Post130682

Pete

What's the issue? These films are very complex chemistry, locked into unstable crystal structures at quench via fast cooling. Some are stable, some are weak, some are brittle, and they are microns thin. They lay over each other like potato chips. Some are stuck to the base material more strongly.
Energy of any form will release some of these structures from their temporary state. Rubbing, UV, solvents, heat, they'll all break the potato chips.

At some point they have to equilibrate. But if you are vibrating atoms with UV energy, some are going to move around.

No one ever mentions it on these discussions, but quench chemistry can be very exciting stuff.