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

We nitride pump housings for wear resistance, and strength improvement. Without secondary machining operations. Finished soft parts go in, wear resistant parts come out.
Does that sound like a cheap shotgun to anyone?

Here's a link to a decent, concise article, that shows most of the blank spots in this discussion. http://www.iaeng.org/publication/IMECS2011/IMECS2011_pp1244-1247.pdf

FWIW, Casenite(sp) changed it's formula a few years back to a "safer" mixture. Should a person have a can of their old formula, you could re-create the article above.

I don't have any idea of how old a can one would have to have but upon my first introduction to casenit some 50 years ago it has always been stated to be Cyanide Free. I have also seen references to, but never further investigated, that one of the chemicals used in film development could be used in the same manner as Casenit.
For those not familiar with temp conversions those temps given in the referenced article in "C" convert to 1454�F to 1688�F.
It should be noted that heating in this very same bath to 1200�F, while it may give a good color will not harden the part but will in fact draw its temper very close to its fully annealed condition.

Having read your vague, non-specific spiel a good number of times throughout the various color case hardening threads, I want to better understand what you are talking about when you say "specific chemicals" and "low controlled heat".

Are you talking "color" restoration with cold blue chemicals, temper colors enhanced by salts, water color paint, what chemicals are you talking about?

How low and controlled of a heat are you talking about? Room temp, 250F, 500F? Applied with a torch, furnace, easy bake oven? Light yellow on steel doesnt start showing up until about 400F and blues and purples dont show up until about 550-600F, how are you achieving color without heating to at least those temps? Unless its a room temperature application I think you are incorrect about your process not affecting the metallurgy, especially if the heat is applied to selective locations via a torch.

Do you really believe that your low/controlled chemical process is better and safer than the original process that hundreds of manufacturers over the years have used as their standard for heat treat? Are you really worried that all the major restoration shops today are producing dangerous work via "High-Heat" color case hardening?

The reason I ask is because I grew up in a gun shop restoring guns and later worked for a well known gun restoration shop throughout college and I have color case hardened hundreds of guns via the traditional bone and wood charcoal method. When I hear things like "specific chemicals" and "low-controlled heat" I cant help but to think what BS that is. I read that as an amateur gunsmith reading the Ithaca-Perazzi manual wiping cold blue all over a receiver.

I actually found that with many restorations the receivers were superficially case hardened from the factory to begin with due to what I believe was the guy at the furnace "eyeballing" the crucible color. Other receivers were quite hard in comparison, especially some L. C. Smiths from what I remember. By todays standards the color case hardening process used by all the major manufacturers to heat treat their actions was an imprecise crap shoot. Funny thing is, for how comparatively imprecise it was we rarely see a cracked frame to this day, but we do see a good number of loose guns. Overall I think the low/controlled heat chemical process you promote is more dangerous to receivers than the modern, precision controlled bone and wood charcoal (original factory standard) of years past does.

Channing Will

joe: after appomattox, some of my ancestors left Alabama and went to brazil. some stayed. some came back. none ever gave up the cause, so far as I know...

and with rare exception, recase hardening a shotgun receiver lessens the value of most guns...this is due to the unknown quality of the receiver metal after it has been subjected to the rehardening process. turnbull and delgrego case hardening work seem to be the most accepted in the market place, with batchelder coming on strong in the stretch...sadly, many buyers are concerned more with looks than function.

cm: please reread the narrative I posted earlier in this thread. it will answer some of your questions regarding the difference between factory case hardening and after market re case hardening. a low heat, chemical process is not case hardening. it is case coloring, in an effort to simulate factory receiver case colors. unlike recase hardening, the low heat, chemical process does not disturb the original factory receiver metallurgy, and hence poses no danger to the gun or shooter...

and please note, i do no gunsmithing work of any kind. i have little specific knowledge of case hardening or case coloring. tony treadwell's book is the best description of the recase hardening process that i am aware of...my approach to all of this is as a hobby gun dealer. if enhancement increases the value of a gun and makes it more sellable at a higher price...great! if not, then don't do it.

...unless you are trying to re-sell them??

If you think "enhancements" that increase value are good for sales, why do you then go on to condemn re-color case hardening in "vain interest of restoring the cosmetic effect of case colors"?

Lets say you purchased a used Parker shotgun and the receiver has been blued by some idiot. You would rather take that action, polish it in a hardened state, and then add imitation case colors with a low heat chemical process that is nothing like what the factory ever produced just to re-sell it at an "enhanced" value? That would be like installing a Pleather covered recoil pad and calling it Leather.

If you admit to having little knowledge of case hardening and case coloring subjects why are you constantly chiming in on these threads?

cm: your posts are starting to get some what confrontational. however, I am trying to keep my responses civil...in an earlier post, I listed three firms that do re case hardening in order to achieve factory like case colors...in my opinion, these three firms have established themselves as experts in the field. whats more, the cost of their work is often recoverable come resale time, but not always. if you have work done to a gun, you should keep the receipt as proof of who did the work. otherwise, it is just another redone gun and worth typically less than if you have proof of who did the work.

as to your parker example, much would depend on the grade and gauge of the gun and what else needed to be done to it in order for any enhancements to make economic sense. wish it was simple, but it is not, particularly in this continuing stagnant economy of ours. buyers and sellers for profit, have to be very diligent and should guard against rapidly changing markets.

although I have little knowledge of refinishing processes, I have lots of experience trying to recover consigner investments in poorly done refinish work. even the cost of well done refinish work is sometimes difficult to recover, particularly if an item was not worthy of the expense to begin with or the work is undocumented. the best rule of thumb I can give you is this: if it is likely that the cost of enhancement will increase the value of the item enough to make a profit, then consider it. if not, or you are not sure, then don't do it. the expense of recase hardening is rarely recoverable. and the risks to damaging the receiver are considerable, regardless of who does the work...this may be why the experts charge so much?

My apologies, I am not aiming to be confrontational. I thought you could shed some light on the subject since you often suggest people should use the low temp controlled chemical process rather than traditional method. I worked for one the three firms you listed and appreciate your rule of thumb regarding restoration, but I can assure you the cost is not related to any risk of damage. The cost is related to the hours it takes to disassemble, clean, anneal, polish, chase engraving, prep and process the parts, reassemble, etc. Send in a prepped part and the process usually cost a couple hundred bucks, not much more than regular bluing. I think with any restoration you will be much better off choosing the original factory processes, thats jmho.

cm: regarding original factory heat treating processes as compared to re case hardening, when a factory heat treated a receiver the metal started out soft and to a known spec as rolled or cast or perhaps annealed to a known spec.

an after factory re heat treating process starts with a receiver that has already been factory heat treated to a known spec. as I understand it, the first step in the re heat treating process is annealing, which destroys the original factory heat treatment of the receiver. step two is coloring, via cooking the receiver above critical temp in a high carbon environment. step three is rehardening the surface of the receiver metal via a quench. and finally step four is tempering the metal back to a less brittle, more elastic state. much of the specs used in re heat treating processes are developed by trial and error, as much of the original factory heat treating specs have been lost...what works for one brand of shotgun receiver, does not work for other brands. and as I understand it, what works on say a parker receiver, vintage 1880, will not necessarily work for a parker receiver, say of vintage 1935, and so on. the tricky part seems to be the tempering step. this is where many inexperienced case hardening mechanics go astray. as you have worked for one of the more successful firms engaged in re case hardening, I would be interested in hearing about your experiences.

as previously indicated, a low heat, chemical process recolors the receiver only and does not change the original factory heat treatment of the receiver... some like the appearance of chemical induced case colors. some do not...perhaps it is best to just leave a fine old gun alone and let it be as is? but, if you must recolor, it makes more sense to me to not mess with the functional parts of the gun, particularly the receiver. better to keep it as originally manufactured and avoid the unintended consequences of reheat treating receiver metal.

As Yogi said, "It's like deja vu all over again" Back under my rock.