Classic old British, German, and other early double shotgun and double rifle actions were made from mild steel, A low carbon steel, usually color case hardened. While talking with one experienced gunsmith, in his very well equipped shop, about the color case hardening process I learned in gunsmithing school, he told me that each time you run such an action through the process of re-color case hardening, you alter the steel in a negative way, and it can never be returned to its original condition. I was thinking, "come on, you don't really believe that, do you?" But he did, passionately so! Another time, when talking to another very experienced gunsmith in his equally well equipped shop, I was just as astounded when he said that you could not TIG weld on a double gun action, saying that he tried it. When I told him the reason for that, is because it first needs to be annealed; then it could be welded, and finally re-color case hardened, but he sounded as if he didn't believe me at all; remained very skeptical. WHAT DO SOME OF YOU EXPERIENCED GUNSMITHS THINK ABOUT THIS?

They were 'not-knowses'.
Regards, Joe

I would agree about tig welding on the case hardened steel. I have experienced some problems with the material "spitting" when welding. Worked through it and did the touch up and the project looked good when finished. I have had the same problem with old steel that wasn't casehardened too just to be fair, so I wouldn't bet my life it was the case causing the problem, just my opinion

He was correct on the first issue and you were correct on the second

For those of you who don't seem to know, the truth is that mild steel, low carbon steel can be annealed and re-color case hardened indefinitely. If you are careful with your heat, and know how to use it, you can anneal a mild steel double gun action and re-color case harden it any of a number of times, without hurting it in the least. Once annealed, you can TIG weld it without any problems, if you know what you are doing, and know how to use the TIG process properly. I have done it, and another chap I know has done it too, so know it can be done. Also, I have repeatedly done color case re-hardening without a problem as well. This covers an area of metalworking that is filled with misinformation, ignorance, and superstition, so it continues to be no surprise that so many people are still unaware of the true facts on this, but for a gunsmith to be uninformed to such an extent is appalling.

well, lets see your evidence.

What Jack said, and plenty of it.

Counselor, we aren't in court and so the rules of legal evidence don't really apply here.

Often the welding problems with early steels are due to inclusions, frequently some sort of carbon. The older steels of the late 19th century are notorious for this, and the carbon seems in my experience to be distributed rather evenly throughout the steel, in tiny pockets rather than in clumps or laminations. VERY difficult to weld attractively, regardless of the welding process.

Also, the inexperienced electric welder, whether TIG or SMAW or MIG, will sometimes encounter microscopic post-weld cracking around the weldment. This is due to no preheat and no Post-Weld Heat Treatment (slow cooldown) in almost every case.

By 'inexperienced' I mean someone unfamiliar with heat-treatment of various steels. A 20-year man may have 20 years' experience or he may have 1 year's experience repeated 19 more times (grin).
Regards, Joe

quote:

I learned in gunsmithing school, he told me that each time you run such an action through the process of re-color case hardening, you alter the steel in a negative way

Well, yes and no. You do run the risk of damage that IS certain. All the guys that specialise in this in "the trade" will always say that there is a risk of "craking" an old action.

And you may need the action to be "rectified" afterwards as sometimes it will slighty "move".

But altering in a negative way? Nothing that I have ever been told here in the UK!

quote:

By 'inexperienced' I mean someone unfamiliar with heat-treatment of various steels. A 20-year man may have 20 years' experience or he may have 1 year's experience repeated 19 more times (grin).

just exactly correct.

quote:

Originally posted by doubleriflejack:
For those of you who don't seem to know, the truth is that mild steel, low carbon steel can be annealed and re-color case hardened indefinitely. If you are careful with your heat, and know how to use it, you can anneal a mild steel double gun action and re-color case harden it any of a number of times, without hurting it in the least. Once annealed, you can TIG weld it without any problems, if you know what you are doing, and know how to use the TIG process properly. I have done it, and another chap I know has done it too, so know it can be done. Also, I have repeatedly done color case re-hardening without a problem as well. This covers an area of metalworking that is filled with misinformation, ignorance, and superstition, so it continues to be no surprise that so many people are still unaware of the true facts on this, but for a gunsmith to be uninformed to such an extent is appalling.

I read your post twice and just scratched my head for a moment. I kept thinking, "Why the fuck did he ask the question if he was not going to listen to any answers that contradicted his already held opinion?"

Why? IMO he did it in order to stimulate a discussion that would further the knowledge base of some of us here, regardless of the opinions we may have held before viewing the discussion. And of course he also did it to show off his own opinion (grin).

An open mind will welcome any further knowledge, even if the factual information is disconcerting or unpleasant. Similarly, a respected person's opinion is always significant, or should be, but how can the average person here actually find out the information unless someone starts a discussion about it?

Many of the posters on this thread, me included, seem to have a portion of the pertinent info but not all of it. By allowing everyone a chance to either impart more knowledge or make a fool of himself, each of us can better arrive at & decide upon the truth for ourselves.

And it's good clean fun and keeps us off the streets (grin).
Regards, Joe

Jack
Correct with stipulations. One you can't just anneal a piece of steel on the bench with a torch and not expect some of the alloying elements to creep out.
Any heat treating process should be done in a controlled furnace by a skilled experienced person. If that requirement is met then yes you could re heat treat a piece of steel with little worry about alloy loss. You could always have it shot to find out what the exact makeup is.

Tig welding on the other hand is a loaded question. What is the base metal??? cast iron can be welded but it depends on the type and grade. and it is usually with very poor results. Cast steel and billet steel is different all together. I've heard more BS spouted in a gun shop then just about anywhere else and it never ceases to amaze me what it passed off for "first hand knowledge"

I think that some of the problems that we run into when welding casehardened steel is that the process itself (casehardening) involves forcing carbon into the surface of the steel from an outside source (charcoal mostly) rather than having the carbon introduced into the metal during the melting process which makes a more homogenous mixture. Then when we try to weld we run into pockets of carbon or other impurities that haven't mixed well with the steel and we get a "spit" from the torch. How annealing helps this problem I don't know. Can someone explain? Thanks.

Every piece of steel has its own challenges. There are so many types.

One certainty from gunsmithing....

A gunsmith dies of old age before he knows it all.

Here's a link to estimating preheat requirements for unknown grades of steel from AWS. I think it's quite handy.

http://www.aws.org/wj/supplement/wj1108-273.pdf

kcstott, Yes, I anneal only in controlled furnace, for this sort of situation; it is the only way to do it for purposes mentioned. I should have mentioned that.
J.D.Steele explained exactly why I posted this, and I also wanted to see if you contributors had similar experiences with business gunsmiths, regarding these concepts. Sorry I may have sounded like a pompous ass in posting this, I didn't mean to come off that way. The base metal is as I stated, mild steel, a low carbon steel. Thank you for all the contributions, a lot of you seem to have a handle on these issues.

quote:

Originally posted by clowdis:
I think that some of the problems that we run into when welding casehardened steel is that the process itself (casehardening) involves forcing carbon into the surface of the steel from an outside source (charcoal mostly) rather than having the carbon introduced into the metal during the melting process which makes a more homogenous mixture. Then when we try to weld we run into pockets of carbon or other impurities that haven't mixed well with the steel and we get a "spit" from the torch. How annealing helps this problem I don't know. Can someone explain? Thanks.

It's not so much that the torch will spit or the metal will pop (same thing either way) It's more of getting a crack after the fact.

The reason this happens is in any welded object the weld bead and HAZ (Heat affected Zone) contracts as it cools to a size smaller then it was before welding. so if the metal near the weld bead is hardened it is also by nature more brittle and therefore can and usually does crack. There are only two ways to deal with this. One as mentioned is to anneal, weld then re heat treat. The other is pre and post heating and maintaining a maximum interpass temp.

In layman's terms you pre heat the part weld on it but don't get it too hot then keep it warm at a certain temp for a given amount of time. This does not anneal the material but it does allow the material to come back to room temp at a much slower rate and therefore reduces the risk of a crack. Keep in mind that if you weld on any part that was heat treated it should be re-heat treated.

What KC said, wish I could have said it that well.

This is the area where the amateur or otherwise inexperienced welder gets caught in his own ignorance of basic heat-treat requirements. The use of TIG, MIG and SMAW procedures is fast, VERY fast when compared to gas welding, and so the beginner is impressed with the speed and lack of widespread heat. He thinks that the lack of heat means that the part isn't adversely affected and, as KC has said, that is just WRONG.

The extremely localized heat of electric welding often results in cracking when, upon completion of the welding, the mass of the unheated portion simply SUCKS the heat right out of the weldment and the rapid 'quenching' causes shrinkage cracking at the perimeter.

I hafta laugh at anyone who says that TIG is so wonderful that they don't need to heat-treat the steel. They are cruisin' for a bruisin', sooner or later.
Regards, Joe