doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com Questions about TIG welding for guns

If you're buying any set it'd be worth finding out where the internal components are made. Many makes use far east parts which are not reliable.
Don't be tempted to buy a scratch start set.
Miller and Lincoln seem to be the favourites on your side of the pond.
An Ac Dc set is great if you'll be welding alloys but a DC only set will save you a lot of money if you only want to weld steels.
Smaller torches such as wp17 and wp9 make life loads easier for more intricate stuff.
Perspex gas lenses that let you see more around the electrode are good but not a necessity, you can stick the electrode out far enough to see what's happening if your gas supply is set right.
Prepare to find out your eyesight isn't as good as it once was, 2.5 or 3 mag reading glasses or 'cheater lenses' that clip into your shield will sort that out though.
Choosing one can be a minefield, I bought a Brit assembled set from a firm over here called R-tech. They use Siemens components and give good guarantees. I've gotta say it's been fantastic having one of my own rather than farming out jobs. Lots of practice has paid off and parts which used to be fit for the bin can now be fixed as good as new.
Good luck with your search.

The pressing job right now is a set of 32" NOS Fox barrels that had never been fitted to a gun by Fox. A file or stone had never had never touched the hook when I got them. Chambers cut, chokes cut, rib matted, ejectors fitted, barrels roll stamped, never blued. I sent them off to a renowned doublegun smith out west to have them fitted to a Fox that has already got a set of 30" barrels. He ruined the hook and when it came back it had maybe 50% contact with the breech face on the right barrel, and none on the left. The hook cut was not circular, but in a long oval, just screwed up.

After some time, I sent it to another doublegun man who advertises that he fits barrels to actions. He welded the hook and "fitted" them. When I got them back there was the same problem. Right barrel on face, left barrel off by at least .003", top to bottom. A good Fox hinge pin is right on .375". A good, clean .375" drill was pressed into the hook and compared to a machinist's rule laid snugly cross the breech face of the barrels. It revealed that the hook was filed way out of square, resulting in the problem. It has to be corrected by welding, or it will never fit properly. You can easily see that the cut on the hook is canted.



I'm sick and tired of paying people who claim they can do something and can't. When they send me a mess like this, I won't even call them and tell them it's screwed up because they will want me to send it back so they can do it over, and that ain't happening. They've already showed me what they are capable of.

I'm going to learn to do this myself, and am making preparations to get the necessary equipment to do it. I plan to build a fixture to hold a set of barrels on a mill table, so that I can set them up with a proper sized pin. Then, I will take them out and weld the hook without moving a thing on the fixture. Next, I will replace the barrels in the fixture, put in a plunge cutting mill, make a few thousandths adjustment to the location, and make a plunge cut to cut a perfect circular cut, leaving just a tiny bit to be removed by file or stone to smoke it in properly.

Thanks for the suggestion, Der Ami. But, in this particular case, that's not the issue. I appreciate the question, tho'.

SRH

Thanks for the suggestions, Nick. C

All points I will give consideration.

SRH

Stan,

Consider taking a class from Dennis Potter. He will show you the correct method. Best teacher in this field I have encountered.
Steve

S

Where and when does he hold his classes, Steve?

SRH

Stan, Dennis held his class at the summer classes in Trinidad ,Co but their schedule is out and the class is not listed.

Fitting "new old stock " barrels can be full of pit falls. Hook may be cut too high or too low, fire pins may not be concentric with chamber centers, out of square breach and lump, 4 end loop issues to name a few.

At the point you are at I would check to see if FPs hit center of primers. If so I would put temporary shim on the hook to set the barrels back enough too smoke fit them tight with good contact to the face. Then remove the shim , build up the hook and smoke fit .

Working both ends to the middle will give you results like you have.

If FPs don't center on primers that would need to be addressed 1st and is whole other issue.

Others may have other ideas but this is how I would go about it.

Thank you, Mark. I had already looked and seen that there wasn't a class listed for next summer, by Dennis or in gunfitting. Maybe 2020.

Thanks for the other information as well. I will check as soon as I can to see if the strikers are hitting dead center. I think they are going to be very close, though, judging by the way the exterior of the barrels fit the breech. The canted cut on the hook causes the right barrel to be off face a little without the forend in place. But, when the f/end is in place it pulls it away and causes the off face barrel to be reversed. In that case, it is the right barrel that is on face and the left that is off.

I think the cut needs to be trued up so that it is dead parallel to the breech faces before I shim and smoke fit the breech faces. Otherwise I'm still going to be "blowing smoke", and really making no progress.

SRH

Stan,
When the hinge pin is replaced, it would be replaced with a larger diameter one to take up the wear( or in the case of your barrels abuse). The fitting of the hook to the hinge pin would be done by "Spot" and "scrape". If the barrels are canted, it wouldn't hurt to check the lugs for fit in the receiver, they shouldn't be able to close canted. There is no doubt that you are better with a mill, than I (everybody is better); but if I tried to straighten this problem out with a mill, I would have it so screwed up, I couldn't sell it for scrap iron. With a scraper, you can take less and take it in a limited area, where the smoke or Prussian blue tells you to take it.
Mike

Stan, don't assume anything is square , parallel or perpendicular on the original gun. Have you checked the original barrels to see how they compare?

Mike, the barrels aren't canted when they close. The cut on the hook is what is canted, badly. What this amounts to is that only a small portion of the hook bearing surface is actually contacting the pin, and only on one side. It wouldn't last 'til the water gets hot, with a lot of shooting.

The mill will only be used to get the cut "close", to hog out most of the excess weld, and establish the proper position of it. The rest will be done as you describe, but I prefer using my little kerosene lamp to smoke the surfaces, as opposed to Prussian blue.



Mark, the firing pins hit dead center on both barrels, so that is not an issue. And, the original barrel set has the hook cut perfectly square, or parallel with the breech faces of the barrels. I checked them in the exact same way I checked the new set shown in the picture.

Thanks to all for the great info and pertinent questions. I called a friend a few minutes ago who teaches welding at a local technical school campus. He said I can sign up for the continuing education course for tig and he will show me the ropes concerning it. He says they have some of the small machines like I would use for delicate work, micro-tigging, as it were. Things are coming together.

SRH