doublegunshop.com - home
I need some help. How do I Properly prepare my receiver to be sent to Turnbull’s for case hardening. Ithaca boxlock. It was case hardened when new obviously. So, before I polish it should it be annealed?? I know it will polish up but does it NEED to be annealed? Is this to relieve stress and make it easier to polish? I’m just worried about the fit after all this heating. If I have to heat it to anneal then again to have it case hardened. I’d rather just polish it as is and have it colored once. Can you guys help me? Thanks!
If I were you I would not heat(anneal) receiver to take the temper out. First you could ruin gun and second there is no need to anneal it to polish it. Unless you know how to polish it I would let them do it. I don't know how much extra it is but if you have never done it, I wouldn't.
If the receiver is not pitted or rusted, it's pretty much ready to go. If there are surface blemishes you need to get rid of, let Turnbull do the heat work and polishing.

If you are handy around tools you can save some bucks by doing a little disassembly ahead of time. NIDs come apart pretty easily, aside possibly from some sticky pins. You will need properly sized cupped punches, a couple fitted screwdrivers, and a custom-made spanner for the mainspring retainer nuts (up front). If you can't get those little nuts on and off properly, pass the job on to the pros. The little screws that hold the firing pins may or may not come out. No matter, the pins can get cased too and Turnbull represents that everything will work fine.
What grade and gauge is this gun? If you let Turnbull Restorations do everything, the cost will exceed the value of the gun.
why don't you ask turnbull?
Turnbull used to offer a short video called "Introduction to metal preparation". I have a copy on VHS but no VHS player. Anyway, it has what you want in there, Jim.

Personally, I see no advantage to annealing if no metal sculpting, engraving or such is going to be done. Both, the annealing and casehardening process will take it up to critical temp. There's nothing obvious to me that would make annealing worth doing in your case.
I have always annealed frames before CC. I learned this many years ago when I worked/engraved for Colt & Win. It is also much easier to hand polish when metal has been annealed. My preference for CC has always been Classic Guns Inc. ---- just my preference only..............
"The original quenching and any subsequent "hard fitting" almost always produces stresses in the steel. Recase-hardening without relieving these stresses can lead to serious warpage and improper fitting after the parts are recase-hardened. Furthermore, parts need to be properly polished and sometimes engraving needs to be recut before refinishing takes place. Polishing a case-hardened steel surface is difficult and surface waviness can result due to slight differences of hardness of different regions...... All of these problems can be alleviated by first annealing all of the previously case-hardened parts. Proper annealing relieves the stresses mentioned above as well as diffusing the carbon in the original case deeper into the metal and transforming the phase of the high-carbon steel to a softer more easily worked material."

This was written by the master, Oscar Gaddy in his excellent articles in DGJ, in part II, Spring 1997.

I have a close friend who has done recase-hardening of double gun receivers and other parts in his home workshop for many years. He has never had a problem with warpage of parts, and gives credit for that to the annealing process always done prior to polishing and subsequent work.

Stan
I too always anneal before re-hardening.
Post deleted by Dave Weber
STAN, You and Oscar are absolutly right. I have used Classic Guns for 10 years without any guns CC by them ever having to be hard fitted due to this process.
© The DoubleGun BBS @ doublegunshop.com