I have a fox ae grade that i want to have re-case color.The engraving is in great condition and does need any work.Do i need to anneal the receiver and polish it lightly or can it be sent out like it is to have it re-cased.I didnt know if it had to be annealed to take the case again.thanks for help.

I think that you need to anneal it. From what I have read by re-casing you can cause the frame to become quite brittle. Again from what I have read and heard annealing is what you need to do.

I am sure someone else will come along shortly to verify.

Regards, Gordon

Also, during the metal preparation the action will be burnished, which will soften the engraving. I strongly advise you to reconsider new case and just let it be what it is--a vintage gun that has earned its' wear.

If I had a Fox I'd have it recase hardened....anyone saw a Fox with a cracked frame that's been recased ?

Per Joe above, think long and hard before you recase.

If your decision is to recase, contact one of the guru guys who does it for a living and discuss; John Gillete comes to mind. It will almost for sure be annealed prior to being recased. I'm of the opinion that annealing is superfulus as the case soak temperature is well above critical (the temperature at which the steel goes dead soft - cooling slowly keeps it soft; annealing). However, it is known that annealing works with warpage being rare. I can't see any downside to annealing first and I mean no criticism of current practice in re-case hardening.

Over many, many years of having different actions color cased after being engraved, I have never had a problem with warpage as all metal is first slowly annealed by John Gillete Of Classic Guns. John also does all my CCH and I have never heard of any of them cracking. FWIW

This gun was bough to be a project gun.the stock is broken on both sides.it got to be restocked.It had a small dent in one barrel that I removed ,so I am going to reblue the barrels.I will have new checkering added.with all this ,why would I not want to have it recased .I know a lot of guys here beleave in keeping it orignal,and I do to when I find a great condition orignal gun,but this is not one.in my opion (and it's not worth much) it would be like wearing a new suit with old shoes.

Anneal first then reharden, let a pro do both steps both end of the process must be controled.

bill

Anyone saw a Damascus barrel blowed up?

The Question here is not necessarily one of "Originality" vs Re-Finish". Case "Hardening" is done by heating a piece of low carbon steel in a carbon rich atmosphere to "Above" its critical temperature & then quenching in water. In 35 years in a machine shop I never saw a piece of steel, either through hardened alloy or case hardened plain carbon, go through the process of being heated above its critical temp & quenched in either an oil or water medium, end up with its "EXACT PRE TREATMENT" dimensions. When these guns were originally made they went through what was known as "Soft Fitting" which was fiting up the gun prior to hardening by file etc or a metal removing process & then "Hard Fitting" which was done after hardening with a "Hammer"; Bending it back into shape after whatever amount of warpage ocured.
Personally I will never submit one of my ±100 yr old guns for "Re-Hardening" & I for sure don't want one annealed & just "Re-Colored".
I am highly skeptical that anyone who says they have never had a frame warp in process are not re-hardening, but just re-coloring, which can be done below the critical temp.
It is likely true that the "Hard" case is not an absolute necessity for the gun to remain safe, they were afterall "Proofed in the White" ""BUT"" the makers went to all that trouble of putting that hard Skin on for a reason (Color was Secondary). I don't want that destroyed on mine.

Heating any shotgun receiver without controlling the temperature and heat duration is potentially dangerous and can damage guns and potentially harm shooters. If a shotgun receiver is heated to critical temperature, such as that required for the bone charcoal hardening process to be effective, then the structure of the metal has been changed and the metal should be tempered back to provide some elasticity. Otherwise, the receiver is as brittle as glass and may crack or shatter upon firing of the gun.

Incorrect tempering of receiver metel is the inherent flaw in the use of the high heat bone charcoal process when applied to shotgun receivers. A dangerous situation may develop as a result of incorrect tempering of the receiver metal after the high heat bone charcoal coloring process is completed. This is particularly true of older shotgun receivers, made prior to ww2. Factory tempering specifications were inconsistent, as receiver metallury formulas changed from time to time. Unfortunately, much of the original factory hardening and tempering specifications have been lost. Even the best of mechanics are only guessing when they attempt to correctly re temper a shotgun receiver after subjecting it to a high heat bone charcoal hardening process.

A low, controlled heat process, combined with specific chemicals is the safest way to recolor a shotgun receiver. So long as the heat is kept low and controlled, the original receiver metallurgy and heat treatment is not changed. No harm is done to the gun nor is there any potential for danger to the shooter, as a result of the re coloring process.

I normally wouldn't post on a subject like this, but I've had it with the misinformation and disinformation on this board, much of it peddled by proponent(s) of "torch coloring" shotgun frames. To start with, the vast majority of prewar guns' frames are made of 1018 or 1020 steel. This is a mild steel with a low carbon content that is NOT hardenable, meaning it can be heated to any temperature no matter how high and quenched and it will not harden. It lacks the carbon content to do so. This is the reason for case hardening. There is no tempering necessary after case hardening in mild steel as the core of the material remains unchanged. Only the surface is hardened to a depth of between .002 and .005". All this talk of drawing and tempering only applies to "through-hardening" steels. No prewar American made shotgun ever used a through-hardening steel in the manufacture of it's frame. I know this because I have the factory drawings for most maker's guns. The material is called out for each part on the drawing. The only thing that torch coloring accomplishes is localized annealing of the remaining case hardened skin on the frame. I contend that this practice is more dangerous than proper case hardening. Before one makes proclamations about metallurgy and what the factories did, they should do some research. Otherwise keep your hazardous opinions to yourself.

Very well said Dewey.......I was biting my tongue myself.
Steve

Thanks Dewey, the facts period.........AMEN....!!..........

Yes, a Charles Boswell. But, most anything can be blown up if improper pressures are applied.

the use of the term torch case hardening infers that the heat source is uncontrolled. i agree, uncontrolled heat applied to a shotgun receiver is a bad idea. almost as bad as heating the receiver up to around 1600 degrees, beyond it's critical temperature and then guessing at what is the correct tempering procedure.
as for research, it ignores reality. the reality is that i and others with far more experience than myself, have seen too many fine pre war guns ruined by high heat case coloring mechanics, who guessed wrong, when they attempted to temper the receiver metal after the high heat bone charcoal re hardening process was completed. the wisdom of experience says not to alter the original factory heat treating in a vane attempt to restore case colors.

Boy,...how I wish Oscar was still with us

Maybe we could light a 'torch' for him...

There is NO tempering involved in case hardening! The material being case hardened is not a through-hardening steel! There is also NO guesswork involved. I am done trying to piss up this rope. Keep doing what you do and I will keep correcting it.

Obsolete material + obscure process + misguided charlatan = eczema. I'll settle for the "ephemera" of case hardening in "protected areas" or graying down. Heat eyes belong in scrap boxes or on steel sculpture.

jack

the wisdom of experience says not to alter the original factory heat treating in a vane attempt to restore case colors.

i have noticed that when this topic comes up, the most fanatical advocates of high heat bone charcoal case coloring usually are individuals that have a vested interest in the process. they often turn out to be some kind of over priced gun refinishing mechanic or engraver who needs a receiver re hardened and recolored, so they can continue to work on a gun and take lots of money from their customers.

Mr. Good quite frankly you and your hypothesis are dead wrong. Please go peddle your adulterated wares elsewhere.

twicebarrel: i am not peddling anything here. that is against the rules.
care to reveal your real name and what your interest in this topic is all about?

Don Kass, who apparently had some experience of the Good/Lander connection, said that Lander had doubleguns shocked up like corn in a very small room. He had to do something with them! Seems to me that lately Mr. Good is searching for "legitimacy" by forsaking the "hot spots" method for something resembling Pipes' description of the oven heat and cold blue artistically deployed method which he derived from--IIRC--published recs. from Perazzi. Whatever Ed's doing to the scrubbed guns for sale on line, his attempt to project his own failings onto others in the trade isn't going to receive aid and comfort here.

jack

Time for a DoubleGun Turkey Day Traditional Torchlight Parade?

That is funny Drew. I laughed out loud.

Mike

Drew for President !

That was funny,man you should be on cable Rev

That's very funny and deservedly so.

There is one way to settle this once and for all. Take one gun and re-case color it repeatedly and see if any distortion or brittleness in the receiver results. Three or four times should settle this for everyone. I have several guns which are candidates and would be willing to submit one of them for testing. Any interest in finding out? I accept Dewey Vicknair's opinion and remarks and willing to back it up with a gun. Maybe we can end this rehash of "to color or not to color" once and for all.

Dewey- After getting a second "professional" opinion, I'd like my PAC 12ga back

Drew- Very nice.

Could you please handle the riot Marc? It's a long cold walk to NH this time of year for me and Mike, and Mearns season opens Sat.

I freely admit that I certainly don't know it all BUT, that being said --- in my now 52 years of ennealing, engraving & having said guns re-color cased vis bone & charcoal --- I haven't had any of them crack or blow. FWIW

John,..I have a box full of SCRAP frames that I've been using over the years to experiment with and perfect my CCH process., some of them have gone through the furnace as many as 10 times and I found that some are more susceptible to movement than others, but they will by the most part have some micromovements after a couple of cicles,.. but it all depends on the action type, the more delicate and dainty the frames are the quicker they start to show signs of movement, but all will anneal back to the softness of butter if properly done.

I've also gone the other route just for the hell of it and quenched some above the critical temperature,...and can tell you from experience that the colours will be unbelievably intense, but the warping comes quick and if done enough times tangs carburize right through and can be easily snapped with a light blow from a hammer.

Doing this will take a lot of dedication because of the big learning curve,..and spending a few bucks on equipment and ready set up components from brownells usually won't cut it. I've been contacted by a few guys that had started to do CCH and were looking for help, but none of them where willing to go the extra mile and put in the time and money required do it right so they gave up, unfortunately the reason they called in the first place was because they'd already screwed something up....well these are the guns that we hear about,the ones that got screwed up, the other ones ( most of them) are still in service and doing great.

CJ

OK, I'm no restoration expert but if I found out after the fact that some guy took a torch to my shotgun so as to phony up case hardining I would be compelled to either kick his a%% so hard he would have to unbutton is collar to take a leak or I'd sue the crap out of him for falsely presenting a bogus restoration. Ed, you may think you're right but you're not.

Be glad to Drew. I know you're really limited on hunting time
Wish I was joining you in a couple weeks.

Marcus

When you run this test don't just "Re-Case Color" but ""RE-CASE (Color) HARDEN". There is a vast & distinct diference between the two. Re-Case "Coloring" will have no affect on the metallurgy except to draw out most of the hardness of the case & leave it in a softened condition.
It is of course quite true the core of a piece of carburized low carbon steel will not become brittle upon quenching. It is also equally true the "Case" itself can & sometimes will if left totally "UnTempered" develop hairline surface cracks. Some steels are more susceptical to this than others. A tempering in the range of 300°F ±25°F will ususally provide adequate protection against this with little detrement to the hardness.
I have personally witnessed this surface checking on a piece of 1018/1020 steel which was "Professionally" case-hardened (not for color),then finish ground into a paralell bar to within ±.0002" dimensions. (Fortunately it wasn't mine).
It is also noted that "Chemical Coloring" (Paint on) is done on warm metal, NOT HOT which does no damage at all to any steel. This method has been described here on several ocasions & was taken from an Ithaca Service Manual for use on Perazzi Receivers, which were I believe an alloy steel & only artificially "Colored" originally.
Some I think are totally confusing this process with "Torch Coloring" in which patches of the steel are heated till they form "Temper Colors". This should be a Crime punishable by hanging from a New Rope for 30 days.
My personal preference on an old gun with the case colors gone is to simply enjoy its character "AS_IS".

i think 2-piper has come up with the best idea yet:

"My personal preference on an old gun with the case colors gone is to simply enjoy its character "AS_IS". "

trouble is, many fine guns have had their receivers polished bright and look awful. re coloring seems to be the best alternative to leaving the gun with a crome plated looking receiver finish. almost as bad is to find the receiver blued.

I have a great little 28 gauge Parker with blued receiver. It will remain blued until it wears off from hunting or goes somewhere else to live. It has more character now than it will if the blue gets polished off or someone decides to make it "new" by recoloring it.

i must confes, i hav no tised ah few blued recever gons from tim tu tim. every now en den, one o dem winchester 21's ore ah brownin bss coms ah long. man, i jes cant wait tu hit it wid de navel jelly an den watch dat blue jes disapears. den i runs de torch over hit, jest ah little bit, don ja know, an den i splashes on ah little pickel juice, an wa la! i got dem bright, i daslin case colors, jes jumpin rite out at me....

ed, i sho is glad you didunt do dat to dat thutty inch bss you sole me las spring!

stan: how did dat won git bye me. ah usuly cuts um back too 24". den de maks nice truck gons.

My '32 Manufrance Ideal 12 showed up this morning from Arizona. Nothing fancy--grade 1 or 2--also a blued frame gun according to the lights of an eagle-eyed friend to the south of here. The fleas come with the dog of course so there are a few cons to this one but it's nice to know I don't even have to momentarily contemplate a metallurgical nightmare over some irridescense the thickness of a soap bubble!

jack

I just noticed that Ed "The Torch Artist", and Dewey Vicknair, SKB, and Miller all have a 3 star rating. Ain't that a bit like adding Jimmy Carters' face to Mt. Rushmore?

Actually, it would be more like adding B. Hussien's face to Mt. Rushmore........

I can see it happening....

Well now i don't know what I may have said to have much Bearing upon my "Star" rating. I have tried to point out the difference betwen a "Torch Job" which is done by applying the tiop of an accetylene torch in a stationary position to a piece of steel until it changes to the desired color, & artificically "Painted ON" colors which are applied to steel warmed to about 160°F. The first is an abomination & Certainly Detrimental to the gun. The 2nd is Non-Damaging. I have advocated neither, simply tried to popint out their differences. Neither will ever provide the beauty of a true "Color Case Hardened" job.
I have also tried my humble best to point out that "ANYTIME" you put a piece of steel in a furnace & heat it to above its critical temperature, there is "RISK" involved. If anyone wants to "Take That Risk" for the sake of a prettier gun, then its thgeir choice, their gun & their money. I just think anyone contemplating having it done needs to be aware there are risks involved.
They also need to be made aware that those beautiful colors can be produced by heating to "Below" the steels critical Temp, but doing so will draw all the hardness from the original treatment (Which incidentally is still there, all that has been lost over the years is the color) & will put none of it back. A quench from below the critical temp does not add hardness, this comes about only from the molecular change of the steel as it exceeds that Critical Temp. This molecular change is also the cause for the risk of warpage etc.
Anyone having "Real Facts" which refute anything I have said on this matter, "Say ON" I am perfectly willing to listen to "Facts".
As to my number of Stars I'm sorta like the Wise Ol Owl, I just don't really give a Hoot.
Me I have some guns with a good amount of what I believe to be original colors, & others with virtually none left. None of them are going into a furnace. Even if I were to acquire one which had been totally polished up it still wouldn't go into a furnace, they'll age real quick if you just sorta let them be.

Lots of discussion, figures I’ll add my two cents.
I always anneal the frame of a case hardened gun when it comes in. Besides normalizing the steel, annealing has a few side benefits; it removes that hard case, making parts easier to polish, it also converts rust to a powder that is easily brushed off, it also makes it possible to re roll tang marking (no way am I using a roll die or stamp on a hardened frame), and makes life easier on my engraver if there is any touch ups that are needed.

Case Hardening is an age old process, the effects are well known to those willing to do the research.

Warpage is going to happen, it might be undetected but will happen, key to minimizing warpage is knowing the correct temps (parts & quench water), proper blockage and knowing how to drop the parts into the quench.

I've only seen one frame that was significantly warped & the buttpalte cracked when the gunsmith tried to install it.

That CCH job was done by another shop( I won't name names) and the gun's owner sent it down to me to "fix". Just by looking at the colors on the frame, the frame had been held too long at temp, quenched at too high a temp & the quench water probably had saline in it.

After annealing,about 5 hours to straighten the frame, and a bit of welding then polishing the frame & parts were re case hardening. Expensive lesson for the owner, I didn't ask what he paid to have it case hardened the first time, but I'm sure it was too much.

Color Case Hardening is a pretty low risk operation, if the person doing the case hardening understands the process.

That abomination called torch coloring…is just that an abomination. You don’t have a clue what you are doing to the metallurgy of the part. Just heating the part to 400 (straw) will start to change the properties.
Don’t know anything about “painting on colors”, I guess it’s like those Beretta “painted” fancy stocks.

Mike Hunter
Hunter Restorations
http://www.Hunterrestorations.com

I have had 3 guns re-casehardened in the past 15 years. A Parker, a Smith, and an Ithaca. Two were done by Turnbull and one by or through Gunter Pfrommer. The colors and workmanship on all three appeared excellent. All three experienced minor warping which did not affect the usability or shootability of the guns. Its just that some of the parts didn't fit as well as they did prior to the re-case. On the Parker, the entire frame spread apart at the rails about .002. On the Smith, one sideplate warped slightly so that it was .001 or 2 proud at one end, and flush at the other. On the Ithaca, the toplever wiggled slightly in the frame. I agree with 2-piper: in the old days, master craftsmen known as "hard fitters" would bend or smack a part back into alignment after the casehardening was complete. If the part broke, they got another one and started from scratch. Today, there aren't any "other ones" to replace a broken part with, so (rightly so, I think) no one is willing to take the risk of smacking or tweaking a warped part back into alignment. JMHO. Bottom line is that I will not re-case another gun. If it too bad to live with, then I simply pass. Good luck.

CJ, I think you have this right. I plan to check a few heat treat facts and will get back with you to see if we are in consensus.

Limapapa;
This agrees exactly with my experience of heat treatment of steels over 35 yrs in a machine shop. This was on both through hardening & case hardened steels, though "Not" shotgun actions. In my experience a piece of steel just "Does Not" go through a furnace & be brought above its critical temp & then be quenched "WITHOUT SOME DIMENSIONAL CHANGE". Ceertainly carelessness in temps can magnify the problems, but it must be understood if that critical temp is not reached then all the hardness of the case will be "Tempered Out" & the part will only be "Colored".
I feel any person performing this work who does not make their customer "FULLY AWARE" of the possibilities is a "SHARK" (If the shoe fits Wear it). The customer can then make their own decision & bear the responsibility.

Sending just a double's frame and furniture to CCH is fine if done between people in the trade,..and this should always be with the understanding that some " proper" hard fitting "could" be required.

Providing this service to the average guy who sends and receives his parts via mail that he himself is expecting to put all back together at home is in my opinion a pretty dangerous practice from a business stand point, word travels fast these days and a couple unhappy clients can cost a lot more in the long run than the few buck that were made taking on the work.

Just like Miller said,...if someone claims to be able to heat up intricately machined pieces of steel in a furnace, subject them to high heat for a long period of time, then rapidly cool them in a tank of water and have them all perfectly engage with the rest of the original components (lockwork , stock and barrels),...100% of the time, he's not telling you all he knows,...but if he is!........... he should buy a lottery ticket

CJ

i would avoid re-color.
look at the bottom view below and you'll see why.

http://www.gunsinternational.com/2834-C-E-Fox-12-g-30bl-98.cfm?gun_id=100106381

Hello Tom,

What area of the Fox are you referring to? The floor plate, or the joint? Just curious. I nearly bought this gun from the fellow that sold it to the current listing dealer, but passed after a brief phone call... Kind of regret it as I would have had her for 1/2 of current asking price and if it wasn't up to snuff, could have returned it.

Jerry

it looks like some heavy buffing was done on that floorplate. cpmpare it to this

http://www.gunsinternational.com/Fox-CE-...un_id=100106106

A low, controlled heat process, combined with specific chemicals is the safest way to recolor a shotgun receiver. So long as the heat is kept low and controlled, the original receiver metallurgy and heat treatment is not changed. No harm is done to the gun nor is there any potential for danger to the shooter, as a result of the re coloring process.

We know precisely how Pipes deploys his low, controlled heat and his cold blue. Precisely how do you do the voodoo that you currently do? What specific chemicals do you use--specifically? Care to share, Ed?

jack

ah useuely holts da torch in mah left han, fur control, dont ya no; an den ah splashes on de pickel jewce wid my right han...

Hadn't thot of pickel jewce in that app. About that fur control--is that for full moon nites when you're really barking?

jack

I have to agree that I have experienced some dimensional changes with a gun being redone using traditional methods. Which brings to mind some of the past discussions about faux case coloring a receiver. Here are some quotes:





I have played with this approach. For a "torch" I used a hand held hair dryer, some have heated the parts in oven at about 160F. It gets hot, but nothing that will affect the metal (stay away from heat guns!) I have "played" with various coloring agents, including betadine, plumb brown, etc. It is easy to correct any "mistakes" with some steel wool.

The result will never pass for a traditional process. But it does no harm either.

Pete

Maybe a little more metallurgy. Steel has several characteristics we need to keep in mind; compressive strength, tensile strength, shear strength, hardness, wear resistance, surface finish, machinabiity, ductility and brittleness. Classic guns have been made of mild steel. It is relatively low in all strengths, hardness, wear resistance, and brittleness. It is high in surface finish, machinability, and ductility. Medium and high carbon steels are much stronger, harder, wear resistant and brittle. They have lower machineability and ductility. All plain carbon steels have about the same modulus; the amount of force needed to deflect (bend) the piece. Springs could be made from mild steel but would have to be limited in deflection to avoid permanent bending; high carbon steel can stand much greater deflection without permanent bending if properly tempered after hardening

Mild steel is nice to work by means of relatively simple (hand) tools and has good surface finish. It is made strong enough for gun parts by designing the part large enough so as not to permanently deform under design loading (cycling and firing forces). Permanent deformation of any gun part is considered failure; breakage is not required. Springs can be an exception by way of small deformation without loss of utility or breakage. Wear resistance is dealt with via case hardening wherein a thin layer of medium/high carbon steel is formed by soaking in a carbon rich environment at elevated temperature.

With higher carbon steel, we now must balance hardness against brittleness. Brittleness is the characteristic of breaking/cracking prior to permanent deformation (ductility). Medium and high carbon steels are subject to heat treating. Hardening is accomplished by heating above a critical temperature and then freezing the steel’s structure by dunking into a quench medium. This produces a very hard, but excessively brittle piece. Some hardness can be traded for less brittleness by tempering, reheating the steel into the 300 – 700 degree F region, depending on the hardness/brittleness balance needed. This same process applies to the core and case of a case hardened piece. If the case is very thin, brittleness doesn’t seem to matter. However, when the case becomes “thick” relative to the thickness of the piece, then brittleness can become an issue. Recasing will thicken the case layer and may increase the percent of carbon (medium to high carbon).

So, annealing will make the case layer soft. Annealing, along with hardening, will have no effect on the mild steel core. Warpage can/does occur with any steel that is heated; it doesn’t take much to affect a precision fitted joint. Fortunately, those craftsmen good at case hardening have found ways to minimize warpage. If, however, a gun part is exposed to multiple case hardening cycles, temper will become an issue. Per CJO above, a tang (relatively thin) can become so carborized as to suffer a brittle fracture unless tempered. I’m not aware of anyone doing post quench tempering on case hardened gun parts; although I think it would be a good idea.

R'Man;
A most excellent & informative post. You have brought up a point which needs to be understood by all contemplating having this done. This is the fact that a carburizing cycle "Changes" the composition of the outer layer (The Case) of the steel. Indeed the depth of the case is controlled by how long a part stays at temp in the carbon mixture. Every time it goes back in the furnace for further heating a little more carbon is added to the case. Thus every time a part goes back in the furnace it will be slightly "Changed" from what it was previously in actual composition. Even alloy steel can experience a slight compositional change in heat treatment from certain alloying elements "Cooking Out" of them, from oxidation. These steels are often heated in a molten salt to minimize this.
The problem with the color case hardening is we cannot simply heat enough for "Just" the color without destroying the hardness of the case, & we cannot process in such a way as to preserve its hardness with out going up into the range where more carbon will be absorbed & the part then be quenched from above its critical temp, which is almost certain to result in "Some Amount" of dimensional change.
To me the Risks are simply not worth it for a little Vanity for the colors. The proper original hardness of the case itself has not been lost, only the color.

Rocketman and Miller,

Those are the two best posts I've ever read on this matter. Thanks for taking the time.

Stan

2p, thanks for the reply. Here are some comments.
You have brought up a point which needs to be understood by all contemplating having this done. This is the fact that a carburizing cycle "Changes" the composition of the outer layer (The Case) of the steel. Indeed the depth of the case is controlled by how long a part stays at temp in the carbon mixture. Every time it goes back in the furnace for further heating a little more carbon is added to the case. Thus every time a part goes back in the furnace it will be slightly "Changed" from what it was previously in actual composition. A craftsman who understood the "change" issue could make a rehardening cycle very short and without a carbon rich environment and still have a hard case. Thus, you would restore the hardness to the case with a minimum of change in case carbon content or depth. Even alloy steel can experience a slight compositional change in heat treatment from certain alloying elements "Cooking Out" of them, from oxidation. These steels are often heated in a molten salt to minimize this. I agree that cooking out and cooking in (usually carbon) alloying elements are issues. Anyone can do a simple case hardening of a simple piece of mild steel. Gun actions are not simple pieces, not at all. Therefore, I will always suggest that gun actions that are to be recased are done only by craftsmen.

The problem with the color case hardening is we cannot simply heat enough for "Just" the color without destroying the hardness of the case, & we cannot process in such a way as to preserve its hardness with out going up into the range where more carbon will be absorbed & the part then be quenched from above its critical temp, which is almost certain to result in "Some Amount" of dimensional change. Certainly recoloring without tempering out the hardness of the case is an issue. Dr. Gaddy thought it paractical. But, I can't yet cite the metalurgy to do it. A careful study of hardness vs temper temperature would need to be made (the higher the temper temperature, the lower the hardness and brittleness). If rehardening, there is no need to soak the piece above critical temperature - reheat and immediately quench will produce full hardness (core temperature is not an issue as it will not heat treat under any circumstances, only surface temperature). Nor is there any need to expose the piece to additional carbon. So, we can see a method to minimize ally changes. There remains the issue of minimizing dimensional changes due to the heating and cooling.
To me the Risks are simply not worth it for a little Vanity for the colors. The proper original hardness of the case itself has not been lost, only the color. [/quote]

In my opinion, and it is only an opinion, most guns can be refurbished to a very acceptable level without recoloring. However, when one is to be fully restored, made as near new as possible, then recoloring is in order. My caution is that recoloring, including rehardening, is not a step to be undertake lightly. A recolored action on a refurbished gun looks out of place. However, a "silver" action on a restored gun also looks wrong. One needs to understand the difference in work and cost between a refurbishment and a restoration.

R'Man;
Several good points there. Yes I think it is true that a total soak of the action would not necessarily be required as long as the surface was heated to aboive the critical temp for the depth of the case. This would be somewhat akin to the process used on some machine tool ways referred to as "Flame Hardened" though a slightly diferent process. Since case hardening itself does not necessarily produce color, I simply don't have the experience here to say whether the colors could be restored with out the addition of "New" animal carbon being added.
Of all the things I ever read from Oscar this was the one place I disagreed with him. I had some correspondance with him via PM, but didn't really get to carry them to their conclusion from his untimely death. His contention was that it was totally unnecessary to quench from above the critical temp & that only the hardness in the case resulting from the higher carbon content was needed. In fact he thought perhaps this was the way the factories processed them. I Disagree. Done this way the only reason for a quench at all would be to produce the colors. It is of course true that even unhardened a high carbon steel is harder than a low carbon one by some amount. I am though firmly convinced that the original method was not just "Color Cased" but "Color Case Hardened".
It is true I believe that the action if totally unhardened would be capable of carrying the load of firing due to an adequate amount of steel, but that wear resistant surface would be lost.

1922



Pete

Case hardening can't increase the tensile strength of the action as the modulus of the case is very near to that of the core. Therefore the core will fail from plastic deformation at the same force with or without the case layer. However, the case layer will be harder and will be more wear resistant; can that be called strength? Also, the higher carbon content will make the case layer more corrosion resistant.

I'm quite sure that the hard layer came before the colors were recognized as "pretty" and desirable. Rub the color layer off and you still have a hard, silver colored, corrosion resistant layer.

Rocketman --- John Gillete of Classic Guns inc. does post quench after the CCH.

Lot's of chatter from lots of people who 'never have'....and 'never will' color case harden any guns......but just read books...and pass out mis-information...

I've only done a hundred or so over the years but have learned:

a...The Manufacturers intentionally serial numbered each part of a gun for a reason...not just because they had nothing better to do.....

b...The guns were in an assembled state, minus the springs, hammers and other parts not cased.....and are the same now by good smiths....screws in place, floor plate or lock plates or both in place ...a tight, secure unit....

c...Then put in a crucible then the furnace....

d...The critical temperature was never surpassed back then and is not now days by experienced smiths...

e...Once all these serial numbered hand fitted parts are cased together, and quenched the proper way...they all become a beautiful matching set of parts.

f...Uberti...Turkish firms...Beretta...Pedersoli, just to name a few are doing quite well with CCH....and even take return guns for re-case....as Colt does...or did...

g...If you've had parts move around, someone screwed up...period


If you like torches and pickle juice or someone elses wear and tear on your gun and you have convinced yourself that it looks good....the 'ol run hard and put away wet look that some call ageing....then leave it like it is and smile from ear to ear.....just throw 'er behind the seat of your pick up.....

I've never understood how a lockplate could be cased without producing a potato chip but reading all whatever it is that I've read and haven't done led me to believe the bits and pieces were packed in there in a disassembled state. I saw a critique of recoloring on a gun which was alleged to have been torched that suggested that the colors (read heat eyes) were bogus because they were continuous across mating seams (say trigger plate and bar or lockplate and bar in the case of a LCS) and that that wouldn't occur if parts were heated separately, as,according to the unstated assumption, they would if the guns were cased by bone charcoal and heat in the time-honored and legitimate process. . . mumble, jumbo, jumble mumbo. Personally, I didn't think that indirect evidence of torching was necessary with that gun but it does make clear that some folks think that in the legitimate process(es) parts were packed in an unmarried state so to speak and might take exception to b. above. Course some folks are wrong some and a lot a lot and a few just a little bit so undoubtedly it might take a team of historians (and a book) to prove or disprove that the one true process has always been followed by everybody (without a clock and a pyrometer) now and forever, world without end, Amen.

Stamping parts with a serial instead of a generic part no. is understandable when and where parts are hand-fitted and one part fits but one gun but I don't see it as more necessary to a procedure for which parts that go together are together than it would be for many procedures (including repair) where they wouldn't. But I admire your confidence that you've seen it all.

jack

On one of your above statements you were absolutely correct, I have "Never" cased a shotgun action. I did serve a certified 4yr machinist apprentiship which included a course in heat treatment of metals. I worked another 31 yrs in machine shops & was in on a lot of heat treatment, just not gun parts.
I can "ABSOLUTELY ASSURE YOU" if the "CRITICAL TEMPERATURE" is not reached the part has not been "CASE HARDENED", only colored. I can equally assure you the gunmakers of old did not go to all that work, expense & time doing all that fancy packing of the parts in charcoal which you have mentioned "JUST FOR THE COLOR", No they Case Hardened Them. They knew there was a high possibility of dimensional changes & did all in their power to minimize it. "If" you didn't go to the critical temp most of that would be totally unnecessary.
If you anneal parts, then heat them "BELOW" the critical temp of the skin then you have Destroyed all the hardness of that original case & insofar as I am concerned have "RUINED" that gun. As Lily Tomlin used to say in the big rocking chair "THAT"S THE TRUTH".
Of course "I DON"T HAVE ANYTHING TO SELL".
PS; Ask any metallurgist what it takes to "Harden" a piece of steel. Hardness is not produced by quenching unless the part is over its critical temp. Just because a piece of 1020 steel happened to be forged into the shape of a dbl shotgun action it doesn't harden any different than a part for anything else. This is a basic metallurgical fact & I was a metal worker.