Perhaps this has been discussed here but I couldn't find what I need doing searches.

Soldering barrels together is not really like soldering sights on or any other soldering job I've done in gunsmithing. I've repaired loose ribs on several double gruns, but I'm tired of all the time spent cleaning up. I use techniques and tools I got from the ACGG's tape of Bill Nitler showing how he did it, but I have two areas I'm looking for help with:

First, I'm having trouble with building a long double torch which can heat the barrels from inside. I first made one up using Oxy-Acetelene, but it pops and sputters badly and just won't stay lit. I made one up using just Acetelene, but the flames go out as soon as I put it down the barrels, so I'm looking for help with a torch. It has to have two heads and about 30-inches long.

The other problem is the flux and solder. Nitler used a paste tinning flux and almost no added wire solder. He mentions in the film that the product he uses has 5-percent silver and is neutralized by heat so clean up is easy. I cat find anything like that. The 5-percent silver tinning flux I found leaves a sticky residue that neither acetone nor soap and water will clean up. I'd sure apreciate hearing from those who've been doing this job.

John,
I don't understand why you want internal heating.

As to solder, 5% silver will raise the melting temp significantly. Hi Force 44 is a 5% silver 95% tin solder and available at Brownells. The melting temp is 475F. I've used it. I see little reason to use it again.

Solder pastes with either acid or rosin flux mixed in are available. I have some I bought. Not worth the trouble and expense IMO.

My technique is to clean all the solder joint surfaces with abrasives, tin them with 60/40 tin/lead solder (360F) using acid flux, clean all the parts with soap and water with Scotchbrite pads, use rosin flux to join the tinned components. I use a large propane torch. Dewey made a fixture and burner arrangement. Heat transfer in steel is pretty quick, internal heating isn't necessary to solder barrels. Oxy-acet inside barrels would cause me concern since the mixture can get well beyond the melting temp of steel.

A few years ago, I documented how I did a re-lay, Dewey had something similar and Drew Hause compiled and posted it here.

http://www.picturetrail.com/sfx/album/view/18691676

I'm attempting to duplicate the techniques of Bill Nitler, as in his video, done by the ACGG. It's the only reference I have. He used internal heat to solder upper and lower ribs all at once. Heating from the inside prevents the flux and the joint from getting contaminated. He used some sort of 5/95 lead-free solder, and considering that when he was alive he was the only factory-authorized Purdy repairman in the US, I figure he'd be a pretty good man to copy from. Thanks for the replies.

I made up some old style soldering irons for the job. I took some copper rod and spun it in the lathe just under bore size and threaded one end. I then attached it to some 1/4" rod threaded to match and welded two of them side by side to fit in the bores. I put the whole unit into a wooden handle and it works well when heated with an acetylene torch. I use kester brand rosin flux and am careful to not over heat it.

John,
HiForce 44 is 5/95 silver/tin solder. It's harder to work with but will give you higher strength if you believe that's necessary for your application. Some guns have high silver or bronze/silver brazing of the ribs. I had a Uggie that was brazed. I worked on a set of barrels from a Belgian gun that were brazed likely with a silver/bronze or silver/tin alloy.

Again, I'd be worried about using oyx/acet in that manner. I think the risks of damage outweigh the benefits. An electric heating element would be my choice if internal heating was what I wanted. Much easier to control IMO.

I believe virtually millions of guns have been put together heating from the outside, probably most or all of the Purdey's as well. H&H heats from the outside in a video I viewed.

I use 60/40 and a paste flux.
Simple no-corrode that washes clear with hot soapy water.
If I do use an acid flux,,it's only for tinning so it can be washed from the surfaces before assembly. Never used for final assembly.

I have use the Force44 tin/silver stuff. It works, works well, but I don't really see any advantage. It needs a little higher temp to work at and I don't care for the forever bright silver line it leaves along a joint.

Lead/tin solder oxidizes to a dull grey with some time and blends in much better. Not an excuse to use solder as a putty filler of sorts though!
Parts must fit together well before hand.

I tin the ribs and most of the bbl surface with a electric soldering gun (WEN pistol grip type, nothing fancy).
Surprising how much of the bbls you can do with one and how quickly.
Ribs are especially easy to over heat while tinning them with a torch,,even a propane. No chance with the 'gun'.

From about the forend lug back to the breech, the bbl mass is too great for the small soldering gun, so I finish that up with the use of an acetylene torch.
I use acetylene here only because I like to be able to take advantage of it's heat potential,,not that a propane won't work, and work just as well. You have to be awfully careful w/acetylene that you don't overheat things.

After the tinning, check it again to make sure it's a nice, thin, smooth coating. Remove any excess lumps and bumps.
I clamp things together w/ a pile of small C clamps and use lengths of rod along the ribs. A few clamps cross wise on the bbls to prevent separation too.
You should have (3) spacers soft soldered in between the tubes along their length also.
(Though I did have one with what appeared to be pieces of popcycle sticks, Never did figure out how they put that together w/o burning them.
They sure did when I went to remove the loose ribs!)


I use clamps,,some use the twisted wire method to secure the new work. What ever works.
I'd been a failure with the wire thing so I started and continue to use the clamps.

I solder everything up when it's set to go using a propane torch. I start at the breech.
Making sure the top rib is set corectly against the short section that's brazed in place.
If you start from the muzzle you can find yourself with an expanded and lengthened rib that's a bit too long to mate nicely with that section at the breech.

Gently tighten the clamps as necessary as you go. Watching the solder melt and flow along the joints and if necessary add a touch of solder.
Hammer flatten the solder wire before starting. It makes for easier access to the joints and the thin profile melts quicker when touched to the steel. Gives just enough. Any excess is just more cleanup work afterwards.

A full length burner sounds nice but I don't know how you'd control the thin portions of the bbl from getting too hot and possibly overheating before the breech section.
Having a full 30" long 400F bbl assembly of several parts clamped or wired together isn't what I'd want to wrestle with.
A temp controled oven of some sort would work, but then there's no easy way to man handle the rigging if you need to adjust the clamping fixtures, add solder, ect.

Take it slow and easy and it works just fine. The entire bbl set doesn't have to fuse at the same moment to make a good soldered joint.
In a factory setting, perhaps that would make for a more time efficient ($$) manner.
But I don't think that's what we're after here. Certainly not what's on my mind when I put one back together.

Simple tools and sound, basic soldering techniques have been the way for a long time.

If your oxy-acetylene torch rig is "popping and sputtering" here's a few thoughts- from my 45 years in the welding trade- First off- make sure the tips are clean and clear- Oxy-acetylene produces a 6000 F temperature with a "balanced" or neutral flame-If you just use acetylene alone, all it will do is smudge- and today, with the explosion at the Union-Carbide plant in TX a while back, acetylene is rationed and very expensive- Mapp gas with oxygen gives about 5600 F at a neutral flame, and commercial propane about 5200 F- propane is mainly used for scrap yard rough metal cutting, and also for heating die bases etc prior to welding--

You cannot interchange fuel gases- without changing both the valves in your torch set, the tips, and also the regulator- I two-stage regulator is always the best buy- both for fuel gas and also oxygen- more expensive, but the cheaper single stage regulators will drop off delivery pressure as the volume in the tank decreases- dual stage regulators will maintain the delivery pressure no matter the volume in the tank(s)--

Trouble-shoot your hoses and connections- use soap water or "Bubble-leak-Check" on all fittings, if you have older hoses with kinks or bends, check- with the delivery value open (you don't need to light the torch here) check under delivery pressure for leaks- if you have them, R&R (remove and replace)-

In regular oxy-acetylene cutting of mild and fab steels, too many 'rookies" use way too high a pressure setting on both acetylene and oxygen- without changing the tip size- thinner gauge metal- smaller tip and orfice openings, lower op. pressures- also- you might see the "red-line" on your acetylene regulator delivery gauge- at over 10-15 range (usual red line markings) acetylene becomes unstable- and if you have multi=-head heating torches, that might be the cause of your problem. Also be careful with delivery and handling of your acetylene tanks- that must be transported and store in the cart UPRIGHT- if you tip an acetylene tank on its side, you should re-stand it upright and wait at least 5 hours for the calcium carbide gas to work from the inert (Fuller's earth or clay compound) that holds it in a somewhat stable condition in the tank-

Solder has a critical temperature of about 500 degrees F--one reason why the Hardware store Turner propane hand held torches will work for "sweating" copper pipe joints--I would like to see photos of this dual torch heating rig of yours before I can comment further- RWTF

I was looking into my Hi Force 44 5/95 and it appears to be a 650F melt temp. 4/96 is apparently 475F melt temp. 63/37 tin/lead melts at 361F Bernzomatic says their propane torches burn at 3450F flame temp

I believe the internal burner rig is running out of oxygen. Some of the underwater oxy-acet rigs had air piped in on top of the o2. Would this setup be used for small gauges too?