True pack Hardening/Case Hardened Colors CAN sometimes be brought back to life if they have been polished off of the surface or removed with something like Bluing Remover.
If the polishing has not been deep, meaning not much metal has been removed, or the bluing remover has not pitted/matted the orig polish of the metal part that was Color CH'd, the now In the White part can be treated to some careful heat to bring the orig CCH pattern back to life along with some colors.
Thin & small pieces can usually be done with nothing more than a propane torch with a pencil flame. A heavier part usually needs an OA torch or oxy/propane. Something with a bit more heat than plain propane.
Hammer/trigger can be done with propane torch.
Don't let the heat get away on you. Meaning you want to heat the part very carefully as the Heat Colors start to appear, back off and watch to see if the old CCH pattern does as well.
Don't let the part get Red Hot. That'll ruin and colors that may appear as the gray color of red heat and heat scale appear at around 900F/red heat on steel.
Tease the color to appear on the part and it will make the pattern reappear as well as it follows the orig pattern of the CCH.
Blues, yellow, red, brown and combinations of them will reappear IF the whole process wants to co-operate!
There is no guarantee.
If unsuccessful,,you have lost nothing but some time and effort.
Let it cool. Repolish the part(s) and send them off to your favorite CCH repair shop for a re-do
There are a couple of ways to create Faux colors. Some are easily seen as that. A couple replicate the look quite well and are usefull for small parts.
The 'Oil and Torch' job is probably the worst way to go and is generally seen as the Hand of Bubba at work.
But Ithaca did at one time use that very method in their Service Dept to refinish older CCH SxS and SBTrap shotgun frames and parts.
I have a copy of the paperwork that was sent to the service/repair dept and outside service repair stations explaining it and how to do it.
Marlin stopped doing any refinishing of older CCH rifles or LCSmith shotguns in very early 70's. Col Brophy put a stop to improper refinishing
of these classic firearms at the factory if they came in.
Then that was followed up with a general business position that MArlin would not 'Repair' any of the older guns that they had mfg'rd.
Lack of Parts was the reason given.
Truth was, sitting above us in the Repair/Service Dept on a second floor at the North HAven factory was tons of orig old Marlin parts.
They had been all tagged, marked, carefully boxed, bagged and wrapped and carted from the NewHaven factory to NorthHaven when the old factory was closed in '69.
A few of us had fun going through them!
'Pack Hardening' (Case HArdening) done w/a Water Quench will give you the 'colors' many associate with the term Color Case Hardening.
If you do the exact same Pack Hardening/Case Hardening process but use an Oil Quench, you will not get the pretty colors that most expect to see.
You will however still get a Surface Hardened part just like with a water quench.
The finish done with an oil quench will be a Blue color and sometimes have a slight swirl of off color grey/blue within it.
The US Krag and the 1903 Springfield rifles were done this method.
Any case hardening final finish appearance can depend on the polish given to the metal, the metal alloy itself, what state of hardness the metal is in when it is introduced into the process (especially if it has been CaseHArdened previously.
The 'pack' make up,,common is a 3:1 and a 2:1 Bone to Wood char mixes.
Furnace temps can be all over the place depending on who does the work. Generally they will be betw 1400F and 1500F
We used to run a very strict 1430F,,+/-2 (or maybe 5?). It's been some yrs now.
Everyone that does the work and gets good results will swear that their time/temps/quench/ box size & shape /drop height /etc are the correct ones.
Of course they are. They are getting you results.
There are way more than one set of correct variables to get results.
Each of the old gun mfg's that did their own CCH finishing had their own 'look' to it. That's because they each had a little different way of doing it by technique and recipes.
They even changed looks over time as newer employees came and went from the finishing dept's.
Polishing has a lot to say about the final look as well just as in bluing.
You have to just find one of those sets in the mass collection of variables you are dealing with.
When you do,,yours are the correct ones,,,for you.
