doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Rifled pattern welded tubes

Damascus exterior liner
http://www.google.com/patents?id=rRlVAAAAEBAJ&printsec=abstract&zoom=4&dq=1181704#PPA1,M1



A modern rendition by Bowen Classic Arms
http://www.bowenclassicarms.com/workshop.html#DamascusBarrelSAArmy
"This particular gun started life as United States Firearms Single-Action Army model in .45 Colt. The composite damascus barrel sports an overlay of English gun tube material..."

How about that Doc Drew. If I'm not mistaken, that modern rendition was made by knife maker Bill Fiorini in Wisconsin. He has since passed away and I don't think Bowen has come up with an alternative.

The commentary on Bowen's site, states that the pistol barrels were a composite of a fluid steel liner and an thin overlay of English gun tube material. This suggests to me that an old damascus tube was applied to the outside of the liner material. This overlay could be silver soldered in place, or could simply be fitted using Acraglas. The downside to this process, is that it would be difficult to have much taper in the barrel tube. Note that the barrel on the Colt and also the barrel on the Vaquero appear to have very straight profiles. Too, for the damascus barrel purist, the liner would always be visible at the muzzle. I don't mean to be negative about the Bowen barrels. I think they have created beautiful guns. Just pointing out how they would differ from an entirely damascus barrel tube.

I am curious if any barrels were ever made by the Warner process. Or, was the patent just for the concept of making them. As a blacksmith, I see some challenges to forge welding that assembly of materials. Not that it couldn't be done; just might be difficult.

I talked to Bill Fiorini several year ago. We didn�t discuss all of the ways that he had welded, or attempted to weld damascus barrels. But at the time, his process was to wrap a riband of damascus material around a solid steel rod. Before wrapping, the riband was shaped to an elongated diamond profile. The edges of the riband were overlapped as it was wound around the rod. While this is a workable method, it is difficult to control the amount of overlap. Variations in the overlap will affect the damascus pattern significantly. There would also be a limit to recreating the old gun barrel damascus patterns by the overlapped riband process. Several of the old patterns, could not be made with an overlapped riband.

Heinz Denig made at least a couple of damascus pistol barrels. It appears to me that Denig used a very similar process to that of Fiorini's.

None of the old gun barrels that I have examined show an indication that the riband edges were overlapped. The riband had square edges and the connection between the turns was a butt weld.



Below are a couple photos of Fiorini doing a barrel welding demo.

Bill Fiorini was a fantastic smith.

Having watched the old documentary video "Making Damascus barrels", I don't think the process is unobtainable now. One of the challenges that would be faced is the stuborness of modern steels compared to the steel/iron mix used in the old barrels.

Watching the way the steel moved under the hammer and when it was being twisted in the video tells me it was much more ductile than what I am used to forging ( all tool steel ). That being said, the right mix of steels to produce a strong barrel but one that is forgeable without so much difficulty would be a key to sucess. Steels like 4140 have an air hardening quality that can be a real pain to deal with.

A mix I would try might be 203E and 1018 with a 4140 core. One issue is wrapping the ribbon around the core and dealing with scale on the inside of the ribbon that would end up trapped. Perhaps a tapered core could be used and once the ribbon is wound, the core could be removed so the scale could be removed and then reinsert the core and finish welding it up. The barrels are obviously tapered anyway so it may save a little machine time in cleaning up the barrel.

Substituting modern steels certainly has its drawbacks. But I think with some testing and research, we can find suitable materials. There is a company in England that sells reclaimed wrought iron. So, the avenue exists to try to match what the old barrels were made of. There are also some modern steels for electrical products that are high silica content. I asked Aldo Bruno (New Jersey Steel Baron) to locate a source for these high silica steels. He hasn't got back to me on them.

I have myself considered 203E and 1018 for damascus barrel steels. I think they are worth a try. I have also thought that it would be great to have a mix of materials that could easily be colored by hot bluing. I've been told that 203E will take color in hot bluing. But I know that nickel will not. Perhaps a combination of nickel and 1018 would be a good choice. It certainly would work for a damascus overlay on a steel liner. There would be no need for etching and fussing with finishing to get the damascus pattern to display. Should be able to just drop it in into a bluing tank and come out with a nice black and white pattern. This mix would also be suitable for any other type of damascus finishing.

You may find it challenging to remove the tapered liner from the wound riband. I often had to use a hammer to start the tapered mandrel out of the riband coil during winding. This is with only a couple turns of riband. I think the turns of riband contract on the mandrel as they cool. Certainly the liner could be separated from the riband coil, with enough force. Just have to sort out how you will do it.

You probably need to consider how you will do some heat treating of the finished barrel tube. The forge welding temperatures will enlarge the grain structure of the steel. You will want to thermal cycle the tube to reduce the grain size and then maybe spheroidize anneal it for machining. I am pretty confident that the old barrel smiths also thermal cycled many of the tubes that they made. There are old writings that state that the best barrels were hammered at a black heat. The amount of cold hammering was sometimes related to the amount of beer supplied to the smiths. They believed that they were compacting the steel, same as the old teachings of packing the edges of knife blades. We know now, that the thermal cycling of the steel was all that was required to refine the grain structure. I believe that many of the old barrels that the barrel finishers have problems with, are a result of the tube not having been properly thermal cycled to reduce the steel's grain size.

This gets complicated pretty quickly, doesn't it?

The thermal cycling is no problem. Salt baths can be used for that to great effect. I had already planed on refining the grain as I don't think the barrel would survive heat treating without it. I used to forged japanese style swords, and still have long tanks and am used to heating and working 30 to 40" bars.

A layer of tin around the mandrel should help remove the mandrel after winding the riband. I wonder if stainless heat treating foil would do the same....

Bailey, aside from the grain refinement, in general what other heat treat would you consider on such low carbon steels. I wonder if tin might contaminate a forge weld. Do you think maybe scale could be removed chemically by some acid and then weld the coil and core in a can, section of pipe. Only curious is all, fun stuff.

I can recall past topic discussions that I believe Bill F. welded the core in rather than remove it because he couldn't get any machine shop to clean up the rough hole, but a solid core could be deep hole drilled. On a thin shotgun barrel, the entire core would be removed, but it acted like a solid bar for machining. I believe he used modern barrel lining techniques with acraglass when he did those barrel projects with Bowen for higher pressure cartridges.

I have enjoyed many, many threads on this fine board, but I must say this one ranks right up near the top. Amazing stuff you gentlemen are writing here about something very few people care about except folk like us. Please continue your posts.

Though I can identify with very little of your techniques and materials, I still grasp enough to appreciate your efforts. You all have wonderful writing skills to boot. Really interesting stuff.
JR

This is an interesting point. I have lost count of how many times I have watched the movie. I have spoken with countless people about it, from gunsmiths to bladesmiths to those that reblacken the barrels. Everyone has a unique observation. It is only through such astute observations that we begin to understand.

I wish I could obtain the rights to the two other movies. One shows the billets being formed in the rolling mills, the other was a 1934 redo of the 1924 movie. I got caught trying to capture them on my camcorder and was quickly stopped and put under very close observation by everyone within ear shot I felt sorry for Marc who was with me.

We really do not know the precise formula for the metals they used. We do know that it became a specialty item over time. I believe the infrastructure could not justify it as newer formulas were developed with a broader market and Belgian gun making began to shrink.

One of these days, the countless conversations about having some samples analyzed and photographed will come to fruition.

Pete

Craig,

The idea of the layer of tin is to provide a sacraficial shim around the tapered mandrel to allow the coil to come off after winding. The tin would be removed from the mandrel before being reinserted. Yes, scale could be removed chemically, reinsert the tapered core and probably tig weld the seams closed for welding the whole together.

Another interesting point would be to setup a fixture in the hydraulic press to help with the jump welds. Hammers tend to swell the steel closer to the hammer blows, while a press will make a billet swell from the center. Having both available during the operation would be handy. Being able to hammer or squeeze the sides, and press the barrel lengthwise would allow the smith to get one more angle on the welding.

Peter,

The use of a rolling mill is a great idea, and I've seen them used to weld billets. I wouldn't use them for my own billets because the way I start my billets the rolling mill wouldn't offer any advantage. I like to use 1/4" thick bars stacked at about 4" tall and 4" long by 1 1/2 wide. The idea is to have thick enough bars to hold their hear for the initial weld, and continue to forge weld for three more cycles as the billet is drawn out. The more drawing of the weld the better as the surface area of the weld surfaces is increased and weld heats are repeated, the more sure each weld will become.

I would love to see more movies. It's a shame anyone would think the process needs to be kept secret, but I guess thats the way it is.

Regarding heat treatment, the core is what needs to be heat treated. The riband needs to be stress releived (along with the core of course) to reduce any warping. It would be heat treated using the times and temps for 4140.

Grain refinement is the absolute key to heat treating. Back in my bladesmith days, I tested a couple of smiths whose blades passed the cutting tests, but groaned and almost imediately broke during the bend tests. The grain structure of the blades were like pyrite. HUGE!! I asked what kind of grain refinement they did and I got the cocker spaniel look.....My Mastesmith test blade went a little past 90 degrees and came back to a 15 degree set. The bottom 2/3 of the blade measured 57 Rc, the spine 1/3 measured 42rc. I did three cycles of subcritical anneals and then hardened the blade and drew a higher temper on the spine.