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

John,
Glad that you are enjoying this thread!

Bailey,
The salt tanks would be perfect for thermal cycling the barrel tube!

The stainless steel heat treating foil might be a plausible aid to removing the riband from the mandrel. I maybe should step back from my comment about the difficulty of removing the mandrel. The barrel that I made had very thick walls, for use as a muzzleloader barrel, with a breech plug. My riband was 1/2" thick. If your riband is thinner, you may not have so much difficulty. I was winding the heavy riband around a 5/8" mandrel. I couldn't afford to allow the mandrel to get hot enough that it would bend inside the riband coil. I used my forge to heat short sections of the riband and wound just a couple of turns at a time. If your riband is thinner, you may be able to heat the riband with a rosebud torch and wind the riband continuously. You're a skilled smith. I'm sure that you'll figure it out.

Craig,
I can understand Bill's difficulty with finding a machine shop that would take on the task of boring a barrel with a forged bore. I wouldn't trust a machine shop to do that work for me.

I did experiment with can welding a barrel tube. I still think it has some possibilities, for a short barrel. Though it poses some challenges. With a can weld, you need to heat the entire can to welding heat. This could require a very large forge, or furnace. You can't see what is happening to the barrel tube during forging. So, you have to make some calculations about how much to compress the unit to close all of the turns in the riband. Not a real problem and additional forging can be continued after removal from the can. The scary part, is that you cannot see that the riband coil is being compressed straight down on itself. It can kink over sideways. If the coil bends sideways, it compresses the turns of riband on one side and wrecks the damascus pattern.

Pete,
I contacted a metallurgical analysis company about testing an old damascus barrel tube forging that I have. This tube, I bought from Peter Dyson. I explained to a representative of this company, that this was a piece of damascus. I was told that they knew what damascus was and that they would have no problem doing the tests on the individual layers. The cost for these tests, would be around $1,000 per sample area. To analyze the two elements in the barrel, plus the chemise, that's $3,000. This conversation was all over the telephone, without them seeing the barrel that I wanted tested. My gut feel, was that they were a little too anxious to promise results, just to collect a payment.

This old barrel tube that I have, is three iron crolle pattern. I have serious doubts that testing can be pin-pointed on the individual layers in the pattern. I might feel better about testing a barrel with Bernard pattern, where the materials in the damascus are laid out in a broader cross section. However, knowing with certainty that there will carbon migration between the layers of material in the damascus, plus the probability of sharing of alloys between the two materials, the results from any testing likely will not give us an accurate analysis of the original composition of the materials before forge welding. We will still be left to make assumptions about the original composition of the materials.

Perhaps we should consider examining other artifacts from the region, and/or find an analysis of the iron ore that was used. If assumptions are to be made, perhaps it would be as accurate to analyze other artifacts that were made in the region. Tools of steel from the area were the barrels were made, as well as wrought iron items from that area could be more easily tested. It would only be a small stretch, to assume that raw materials (steel/iron) produced in the region and supplied to all craftsmen in the area would be of similar composition.

I REALLY would like visit the museums in Belgium to see the other movies and view the barrel making artifacts. I have some very specific questions that I feel could be answered, if I could get there. Just can't afford the expense to do it right now.

Steve: TSI in MN performs industrial metal testing, and has evaluated a few pattern welded barrels
http://www.tsi.com/

Thanks for taking the time guys. Interesting stuff, and all of you have great contributions.

Drew,
This is very interesting and I would love to see the results of their analysis. I would also like to talk to them about the capabilities of their testing process. Still, I am skeptical about the value of the results, due to the expected alloy sharing that happens at welding heat. Guess I would just have to see the numbers before I could trust that they were valid. I think that I could make a semi-educated guess about the materials used, and come as close to being correct as the results from lab testing forge welded steels.

Over a year ago, I gave samples of the barrel tube that I have to a couple guys that I know through knifemaking circles. One guy thought that he could get it professionally analyzed for me; the other has a small metallurgical lab in his shop. Haven't heard back from either of them. Guess I should rattle their cages and see if they have done anything with the samples. Hate to bug them too much, as I was asking a favor to have the testing done on the cheap.

Given the right lab, I am willing to cut a bit of the ribbons from the end of my demonstration barrel.



This will be the very end where they have not yet been twisted.

Regarding the billets at the rolling mill. They were huge. I calculated the numbers once, can't find my notes at the moment. The mills ran this specialty product on a monthly basis based on orders supplied in advance by the barrel makers. So for example, a couple of billets would supply all the chain damascus for a month. The billets would be sliced to produce the correct number of ribbons to fulfill the orders.

In Liege, they have the actual billets. Unfortunately, they are no longer on display since the reorganization of the display space.

I have a set of barrels from Dyson as well. I always thought they were too complicated to get good results.

Steve if you can find the right lab.... let me know. But they have to prove themselves before I start cutting.

Pete

Pete,
I would consider calling TSI to ask what they can do. Perhaps they can explain to me how the testing would be conducted. I am interested to hear what Drew knows of their previous testing on damascus barrels.

The end of the unwound riband would provide the best material for testing. It would still require pinpoint accuracy at the center of each layer, to get a representative analysis. I feel that it would be tough run a good test on patterned material. But I have to be honest, I really don't know much about how metallurgical testing is done.

I looked at their website. I will call. They will need a SEM, Energy Dispersive X-ray and a Wavelength Spectrometer.

I went through my old emails. There is a gentleman who posts here on occasion who may be able to help.

Pete

I called TSI. They do not do metallurgical testing of the type required.

Pete

Mike Franzen's thread on PGCA regarding testing done by TSI. I am unable to comment regarding the techniques used
http://parkerguns.org/forums/showthread.php?t=9647

I can not see the images, as I am not a member. From the sound of it, he was looking for very different information. I am not interested in occlusions or wall thickness.

If someone here is, then I invite them to finance the effort and use TSI.

Pete