Repair of Deep Pitting

[PhilOhio]

This is a subject which has intrigued me for a long time, as restoration of basket case firearms is something I enjoy. I don't expect to ever make a dime from it. It's just a good thing to do, in my opinion. A recent thread prompted me to raise the question. So while some may be unwilling to share their knowledge, others, including me, feel differently. I would like to ask the group about their experiences in repairing areas of deep pitting by replacing metal, resurfacing it, and rebluing. I know that some of you do outstanding work in restoring nice guns which have been badly abused.

In a few cases, I have done this by bead blasting, careful welding, and re-machining with lathe, milling machine, or bench grinder. It works, but is tedious and less than ideal for many situations. It's just a matter of how badly you want to do it. Overlapping the welds to get a smooth machined surface in the end is difficult.

For restoring worn or pitted parts on large machines, like bearing surfaces on my 1941 John Deere tractor's steering shaft, a local automotive specialty shop used high tech equipment to very precisely flame deposit metal where needed. But I don't know enough about that method to know whether it could be applied to much smaller firearms components, and how precisely you can regulate the process. Restorers of very rare and valuable firearms clearly have access to a technique which works well. We see the result often. What are they doing that I don't know about? It must be something predictable, not too difficult, very controllable, and not overly expensive. I would guess the major ingredient is skill and attention to detail.

For what I want, new metal has to be rather permanently fused to the clean pitted steel surface, machineable, and blueable; and it must be a technique within the ability of a normal human being who does not have access to a $50,000,000 factory with state of the art CNC centers.

I'm sure such information is on the Internet, and I have not searched yet; just thought I would ask here first, as some of you obviously know the answer. And I guess it's a good test of how the board sometimes works to broaden our mutual knowledge base to save nice old firearms for future generations.

[Ron Wood]

All the restorers that I am aware of that resurrect basket case pitted guns build up the pits by TIG welding. If you can get your hands on the 4th Edition of Gun Collector's Digest (1985) there is an eye-popping article by Gale Morgan titled "1300 Grams of Rust...a photo essay on the restoration of a rare Broomhandle". It is 10 pages of step-by-step rebuilding of a rust pitted relic of a 20-shot Mauser. It is a TIG welding and machining tour de force.

[Edward Tinker]

I have had a basket case or two that I thought of restoring, and even sent it to a well known restorer. He said, "Id rather not do this one"...

It came down to time and money, it costs too much for the average person to have done, unless it is sentimental or really rare. With the welding, fixing, welding and then bluing to make it look correct. And if sentimental, to me, it would have to be some kind of water accident that happened after Dad brought it home...

One of the restorers messed with a 1900 (or was it a 1906) for months and months, sending it out to a friend, adding metal, smoothing, adding metal. In the end I think the result was still under par.

For a "fun project" it might be worth it, if you can do it yourself, but otherwise, I have sold my basket cases for parts; as it just wasn't worth it to me.

Ed

PS: I don't think I blame a person like Ted in not wanting to share "secrets" as he spent a lot of time and money getting the results just right. He could write a book on the process and maybe make a $1,000 over 5 years selling each book; seems like a small amount, but books like this aren't best sellers only so many folks looking for info on gun bluing / repair etc.

[Thor]

Originally Posted by Ron Wood

there is an eye-popping article by Gale Morgan

Actually a good read! Gale is remarkable and very patient.

Thanks Ed for your comment too, you are right on of course!
How is the Simson Collection coming?? I heard you wrote a book on them! Superb!

[PhilOhio]

Gentlemen,

Thanks for the responses. As Ed suggests, repair of major pitting is never likely to be a cost effective undertaking. I do it (rarely) because I enjoy it and can, if I have the time and really want to. My primitive method has been to bead blast and then overlap a series of weld beads using 1/16" rod at about 50 to 55 amps with a conventional arc welder. All "hits" are less than one second, so good visibility and an instant auto-darkening helmet lense are essential; can't be done any other way. But this is very demanding and difficult. And then you have to do some delicate machining and/or grinding to get back to a level surface. TIG would be much better, but I don't have that gear.

On rounded surfaces, it's tough, unless you can mount the weld-filled piece in a metal lathe and turn it back down. So it can be done with barrels. I did it with one of my Thompson barrels years ago...a barrel which a professional gunsmith had badly carved up with a hacksaw, besides the pitting, because that was the easiest thing to do when removing it, and he didn't think the barrel was worth much; "then", that is.

The easiest part of the whole job is putting on the blue or parkerizing; so far, I've always gotten a perfectly blended match, as long as there is no nickel or chromium in the original gun alloy or the welding rod used for filler. If you use the wrong rod, no way will you match it, although you can cover it over nicely with one of the modern spray-on finishes...but not on a Luger.

Guys, have I learned a lot after a few hours of Internet research yesterday. There is a much better and easier way to do all this if you have access to certain modern technology, which is rather widely distributed.

There is a process called "arc thermal spraying", and there are about three other closely related processes. All involve using clean dry air, or an inert gas, to blow liquified droplets of metal onto your pitted surface, which has been sand or bead blasted and made very clean.

Before solidifying, the droplets flatten and overlap. You have perfectly fused new metal, much like welding, if you did it right.

One of the best part is that the substrate, your gun or gun parts, get barely any heat. They are not warped or distorted. And because of the lack of a heat threat, you can use certain masking tapes to mask off your pitted area, as though you were spray painting; which is exactly what is being done.

Some versions of the equipment dispense powdered metal and others use two wire-feed electrodes which arc, to produce the droplets. All versions do the same thing, build up your surface with newly fused metal droplets.

Much of the equipment consists of small, very portable components; it's intended for field use on damaged equipment or parts. I think most of it looks too expensive for basement hobbyist use, but quite a number of small repair companies have it and advertise that you can send them your gear for repair, at reasonable cost. I would imagine that could include gun parts. I expect that in most urban areas somebody has this stuff.

Almost any metal works. It is being done with steel, brass, aluminum, and a variety of alloys including monel and even carbide, for restoring large cutting tools and such things as scraper blades and industrial teeth of various types.

Sounds to me like some miraculous fun technology, and I thought some of you might like to know. People are offering these services all over the net. Do a search on "arc thermal spraying".

Oh, yes, sorry I did not save the url, but the U.S. Navy is into this in a big way, for repair of everything under the sun on ships, from small stuff to hulls. On the net, I found publication of the Navy's wonderful overview training manual for explaining to new maintenance trainees what main technologies are out there (four, I believe), how they work, and very precisely how you do it yourself...and what to avoid.

For those of you who are incurable restorers, as I am, I hope you enjoy looking into this on the net. It's something to keep in mind, next time you have a worthwhile collector firearm which may be in pretty good general condition, except for a very localized area of deep pitting damage; send it out for a minor skin graft.

What would be really neat is if there were a version of this sprayer small enough to use like an air brush. Maybe there is. The ones I saw were about the size of a gun you would use for spray painting a car.

[Vlim]

Found it.

Have a look at

http://www.rustbusters.com

and

http://www.rustbustersllc.com

One of the sites even has a nice video of the process.

[Ice]

This is an excellent post full of valuable information. Thanks for sharing.

Charlie

[PhilOhio]

Yes, the URLs posted by Vlim involve exactly this ATS technology. They are using it on very thin gauge metal, auto bodies. And they are promoting the use of filler metal which gives a galvanized surface, which we would not want with firearms, because you cannot blue it. But any filler metal can be used with their equipment, including mild steel compatible with firearms which are to be blued.

Note that they say the temperature of the substrate onto which you spray the new metal is not raised above 100 degrees. That's only 30 degrees above typical room temperature. Amazing. The heat rise problem is a major concern when you use arc or TIG welding to replace pitted steel.

Notice their offer to demonstrate the technology if you send in a part for them to fill for you, if you call first.

The gear must be pricey, since they don't want to tell us right up front, and they refer to leasing arrangements.

I sure could have some fun with that equipment. I guess some folks already are.

[Ron Wood]

They mention "about the cost of a new truck".

[alvin]

I read Gale Morgan's article, and summerized out this equation:

professional restoration = build up edges and corners

From his article, most important, he's very experienced and he knew what can be fixed via TIG welding, what does not worth the effort and he just cut it away and weld a replacement on it. That paper implied he did not have factory blueprint either, but he measured from a good one (not exactly the same variation, but close enough). And he had a bunch of parts guns to donate organs, original guns for reference, ....., his summary of German gun finish was accurate to the home "crisp but not sharp, smooth but not over polished" (not exact words, I don't have his artcle at hand)

[PhilOhio]

As Alvin notes, corner and edge buildup is a key part of serious professional restorations. In most cases, it could never be cost effective, even if possible. But with this arc thermal spray technology, I don't think it would be too difficult to selectively/locally add new metal, especially since you can mask. The tough part would be having all the right cutters and skill to remove part of the built up metal to get back to the way things were originally.

I did a quick check of Harbor Freight's website, as they have an impressive selection of modern welding equipment and expendables; some good and some not so good. They don't appear to have it yet. Yet. If and when the Chinese figure out how to build and market a low cost, entry level ATS system we can afford, I want to be at the front of the line. They did it with mini mills, and that was life changing. ATS is next. It would not surprise me at all.

I'm guessing that some of the ATS equipment on the U.S. market is Chinese built, and we are not seeing cheap versions because of contract considerations. But over there, technology leaks pretty fast, and as for contracts and the Chinese...

[alvin]

ATS? Never heard of it. But if can make money, I am sure someone will replicate it. I have seen Mountain Village Edition iPhone, functional, cheap, probably $50-$60 (?) After all, it's not a very complex technology.

I also heard this story on the web. Charles Dickens visited New York in 19th century and felt very angry when he saw illegal copy of his book floating on the market. The purpose of this story was obvious: this is a stage

"Theory before action"

[PhilOhio]

Alvin, you've never heard of ATS? Not even in this thread? See my last post above.

I had not heard the term either, until this past week, when I began researching it. I generally knew of the process, and as early as 1997 I had it done locally on my antique tractor steering shaft's rear bearing surface, but I did not know the term.

So the process is not totally new.

And guys, the Navy says there are three other distinct, but slightly different, technologies which do pretty much the same thing. I forget their names. One uses metal powder instead of wire electrodes. ATS just seems to be the one most commonly seen; maybe its the easiest or least expensive, or something.

...dirt cheap..."almost the cost of a new truck".

[alvin]

Has anyone shot professionally restored Lugers, do they work smoothly?

I played a few arsenal refurbished guns, CZ, Nagant, Browning etc (no Luger), they shoot safe, but none of them are accurate and have various kinds of small issues, such as headspace mismatch, prime piercing, feeding jam, ejecting jam, etc, etc.

[Ice]

I owned one professionally restored 1918 DWM Luger years ago. Was really ignorant at that time and shot it quite a bit. It looked and functioned like a new one and was quite accurate. By definition, a professionally restored firearm looks and functions like one just from the factory. I traded it for a 95% original .45 Colt Peacemaker with 4 3/4" barrel made in 1898. After all these many years I guess I made out better in the trade. I still have the Peacemaker.

To add, this was 30 years ago and I didn't know anything about Lugers except it was a nice pistol. The guy kept bugging me, wanting it and offered the Colt in trade. I made the trade without any idea of cheating anyone.

Charlie

[sheepherder]

Originally Posted by Ice

I still have the Peacemaker.

Charlie

Charlie - I understand peacemakers are susceptible to radio transmissions and neon signs...Any problems with yours???

[Ice]

I keep it securely wrapped in double strength aluminum foil. Sometimes I have to take it out for walks after midnight.

Charlie

[Vlim]

Alvin,

It all depends on what part of the pistol has been restored or refurbished. If the gun is matching to start with and all the major pieces have little or no internal damage (as most restoration cadidates seem to have), the repairs will be mainly of an optical nature. I had the chance to shoot a P08 in Germany that had spent some 30+ years in a river, was retreived, had a barrel liner installed and the springs replaced. After many thousands of shots it was still going strong and grouping nicely. It still looked like it was fished out of a river, though

I also had a 1917 DWM LP08 that looked like it had spent 80 years in a damp basement. The outside was heavily pitted, but the interior was like new. It shot very, very accurately.

As long as they don't mess with the innards too much, restoration shouldn't result in a bad shooting gun.

[sheepherder]

Originally Posted by Vlim

I also had a 1917 DWM LP08 that looked like it had spent 80 years in a damp basement. The outside was heavily pitted, but the interior was like new. It shot very, very accurately.

there was one that sold on GB some time back (I think I linked/copied a pic from the auction) that sold for $440 IIRC, and the description said that the lady of the house had stored it in a rag in a corner of the basement...did you buy that one???

It was really corroded, externally...

[Vlim]

I remember that one, but it wasn't mine.

Here's a scan of the old girl's best side. The major pitting was on the right side, and a restorer had to remove quite a bit of metal to make it presentable. The side plate is a replacement, the original had little or no shape left. I also replaced a number of smaller parts, like the trigger, take down lever and safety lever. At that time I was looking for a shooter arty, so the technical shape was more important than the looks (it also helped to make it 'affordable').