TIG weld question for the experts

rsako

rsako

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Hi fello smiths.

Working on a mod to an old Mauser 98 bolt handle. My welding looks like sparrow poop šŸ¤ ...so my expert welding buddy is going to give it a go.

Question is: what rod to use? Stainless 309? Regular carbon steel rod produces real small air bubbles when i dress out the test welds he tried with carbon steel rod.

This bolt had a big crack from a previous weld 50 years ago. And then i discovered a big air pocket when profiling it the way i wanted it to look. Ground it out...test welded again but still getting air bubbles and contaminents during weld with the carbon steel rod. Perhaps it was originaly silver soldered on...we don't know that now.

We've never seen in this in all the years.

Tips from the pros? Rod type...settings.. etc..
 
That is what I have always used for bolt handle alterations. Works beautifully with oxy-acetylene.
 
1 It has to be a de-oxidized rod with tig welding mild steel.
2 When using stainless always go up to a more noble metal. So if the item is 309 I would use a 310 or a 316 filler rod with tig.
tigrr is my handle from tig welding for 30 years.
Nickel is used for cast welding, it is soft. The bubbles could be from not using the de-oxidized rod or poor gas shielding.
Polish the lugs for easier bolt extraction.
 
To tig that steel all you need is er 70s6 or es70s2.
Any one who tig welds mild steel uses this rod all day. Mig wire is the same designation on steel.You u can find it at a bus stop very common.Blues quite well.
There is no reference by the op as to his weld process.If it is tig when steel is prepared correctly there would be no problems at all.Tig welding jobs have to be very clean or it can give you much trouble.Remember stainless doesn't blue. Tigrr has sound info as well.
 
Awesome info. Many thanks to all! Anyone know if there is a source for this welding rod in Canada?
Or perhaps someone can spare a couple for $$. ?
 
ronnie01 said:
To tig that steel all you need is er 70s6 or es70s2.
Any one who tig welds mild steel uses this rod all day. Mig wire is the same designation on steel.You u can find it at a bus stop very common.Blues quite well.
There is no reference by the op as to his weld process.If it is tig when steel is prepared correctly there would be no problems at all.Tig welding jobs have to be very clean or it can give you much trouble.Remember stainless doesn't blue. Tigrr has sound info as well.
Click to expand...

You mean, other than his post title? "TIG weld question for the experts "

:)

Having aided and abetted in a couple or three TIG welded bolts over the years, all I have to say is that if it is blowing out chunks and generally causing grief, then the problem is probably not going to be cured by a different rod.

It may be worth a try, but have a plan that may include replacing more of the bolt handle than you initially thought reasonable.

FWIW, the nastiest weld I ever saw a guy pull off was a set of cupons of laminated steel shimstock, call it around 40 layers of thin steel held together with a low strength solder. The welder was pretty sure he had some bad rod and bad gas, powered on through to the end of the bead. Got a good laugh out of it too, after he found out what he was welding. Proof positive that sometimes, stock off the rack isn't what it is supposed to be, eh?

Cheers
Trev
 
ronnie01 said:
To tig that steel all you need is er 70s6 or es70s2.
Any one who tig welds mild steel uses this rod all day. Mig wire is the same designation on steel.You u can find it at a bus stop very common.Blues quite well.
There is no reference by the op as to his weld process.If it is tig when steel is prepared correctly there would be no problems at all.Tig welding jobs have to be very clean or it can give you much trouble.Remember stainless doesn't blue. Tigrr has sound info as well.
Click to expand...

X2 the rod is very common and can be found at any welding supply house, Linde, Praxair, or Air Liquide.
 
If the bolt handle is just steel than i don't know why your having such a hard time welding it. If your getting porosity than my guess is either gonna be wrong shielding gas, wrong tungsten or wrong filler rod. Try welding on a piece of scrap first and see if you still get porosity. But what gas, rod and tungsten are you using?
 
rsako said:
Hi fello smiths.

This bolt had a big crack from a previous weld 50 years ago. And then i discovered a big air pocket when profiling it the way i wanted it to look. Ground it out...test welded again but still getting air bubbles and contaminents during weld with the carbon steel rod. Perhaps it was originaly silver soldered on...we don't know that now.
Click to expand...

^^THIS^^
Once a joint has been brazed or soldered it will be very difficult to weld with any process. OP you may need to take more off the work piece, the entire infected area needs to be removed or it will continue to contaminate the weld.
Joe
 
rsako said:
Hi fello smiths.

Working on a mod to an old Mauser 98 bolt handle. My welding looks like sparrow poop ļ¤ ...so my expert welding buddy is going to give it a go.

Question is: what rod to use? Stainless 309? Regular carbon steel rod produces real small air bubbles when i dress out the test welds he tried with carbon steel rod.

This bolt had a big crack from a previous weld 50 years ago. And then i discovered a big air pocket when profiling it the way i wanted it to look. Ground it out...test welded again but still getting air bubbles and contaminents during weld with the carbon steel rod. Perhaps it was originaly silver soldered on...we don't know that now.

We've never seen in this in all the years.

Tips from the pros? Rod type...settings.. etc..
Click to expand...

You are in Edmonton just go to Princess auto they have the tig rod you need it is not special. Go to a body shop and get a couple of feet of mig wire in .045" it will be what you need.
If you ask your tig buddy he will have it. If you can't find some let me know and I will post you some I have ton's of it in .035" .045" 1/16" 3/32" it is just the every day tig rod for mild steel. A picture of your weld so far would help a lot. Is it a weld you did yourself? If so what welder did you use the gas and the amps and the filler rod would help much. There is no magic rod to do that job. If you have pores and bubbling welds something is contaminating the weld.Tig welding has to be squeaky clean no exceptions.If it was brazed or silver soldered you can't tig it,with any of the previous repair present or you will give yourself a non tig weldable joint. Pictures will help.
Hope this helps out let us know how it is progressing.

R
 
joehunt said:
^^THIS^^
Once a joint has been brazed or soldered it will be very difficult to weld with any process. OP you may need to take more off the work piece, the entire infected area needs to be removed or it will continue to contaminate the weld.
Joe
Click to expand...

I second that.Only thing I would add is whatever you do don't use stainless filler rod.Stainless steel will weld nicely-no doubt there,problem is that weld will be very soft and ductile.

I'm not educated enough to explain that correctly but SS when heated and not treated properly is incredibly soft.Welded bolt handle with it will brake sooner than you think.
 
I recall someone a little while back saying to degreas, and then apply cold blue. If there is any brazing or solder, it won't blue, so is easier to see, and grind off. Sounded like a helpful trick to help identify possible issues.
 
donor said:
I second that.Only thing I would add is whatever you do don't use stainless filler rod.Stainless steel will weld nicely-no doubt there,problem is that weld will be very soft and ductile.

I'm not educated enough to explain that correctly but SS when heated and not treated properly is incredibly soft.Welded bolt handle with it will brake sooner than you think.
Click to expand...

If the bolt itself is stainless then that's a very bad idea. Introduction of carbon steel to stainless causes contamination and the affected area will soon begin to rust. Tiggr had the best info as far as I can tell. I'm new to TIG welding, but can tell you that he's 100% correct on using a higher quality rod than the parent metal, otherwise you'll end up with contamination.

Some pictures may help to show what you're working with and what the issues may be. What type/series of metal is the bolt made of?
 
Marlon94 said:
If the bolt itself is stainless then that's a very bad idea. Introduction of carbon steel to stainless causes contamination and the affected area will soon begin to rust. Tiggr had the best info as far as I can tell. I'm new to TIG welding, but can tell you that he's 100% correct on using a higher quality rod than the parent metal, otherwise you'll end up with contamination.

Some pictures may help to show what you're working with and what the issues may be. What type/series of metal is the bolt made of?
Click to expand...

It's an old Mauser 98 bolt. If you got info that there were ever a bunch made in Stainless, I am sure a bunch of folks would like to hear!

Stainless filler is out, unless the OP wishes to only ever paint the gun parts going on in to the future.

In my best (unseen, first hand) estimate, the original repair that he ran in to was like as not, an issue for the guy that welded it, but he got through and made it work. The weld did eventually fail, which is why the OP is in there now.

Aside from the residue of a questionable weld, there is like to be a fair bit of residue from various oils, maybe cold blue, etc., in the crack, all of which needs to be removed. The original crappy weld, all has to go.

Then it becomes a matter of cleanliness, good welding practices and patience, building up the cut away area, without resorting to hiding your errors under a good looking top layer, like the last guy seems to have done.

With a TIG machine that will go low enough, and a decent foot pedal for control, you can literally build up arches and build a web of bead across open space. It is a good deal tougher to do that kind of welding if you have a fixed amperage rig, like a scratch start, or a machine that just won't dial down low enough.

Like I said before. Make a plan that might include having to weld on an entirely new bolt handle. At the very least, welding in a section tor replace what gets cut away in order to find sound metal to weld.

Enough bolts have been welded with Oxy-Acet and coat hanger wire for filler, that I am of the opinion that settings and filler choice changes are not what you need to be looking at all that hard. Clean away the bad, and build from there.

Cheers
Trev
 
For what its worth, here is the method that I use with oxy-acetylene...
For the nicest looking job, replace the bolt handle, with a nicely contoured, swept one.
Set up the bolt handle stump and the new handle with a notch that will be filled when welded. Use a jig to securely clamp the bolt and handle in position. Double check. Install a heat sink in the rear of the bolt. Use anti-scale compound. Cover the rear of the bolt with anti-scale compound, wrap the body and locking lugs in wet rags. Use a medium flame, bring the stump and handle to heat quickly, fill the notch with Brownell's rod.
Clean, file, polish.
Original military handles can be altered, using a similar technique. Saw diagonally almost all the way through the root of the handle. Heat the "hinge" left after cutting, bend the handle down. Fill the notch. Heat the handle shank, bend for outward and back sweep as desired. Use a heat sink and anti-scale compound as above. Clean, file, polish.
No doubt a handle can be reworked with TIG, using a similar setup.
Can't imagine using a stick welder for the job, although apparently it has been done.
 
tigrr said:
1 It has to be a de-oxidized rod with tig welding mild steel.
2 When using stainless always go up to a more noble metal. So if the item is 309 I would use a 310 or a 316 filler rod with tig.
tigrr is my handle from tig welding for 30 years.
Nickel is used for cast welding, it is soft. The bubbles could be from not using the de-oxidized rod or poor gas shielding.
Polish the lugs for easier bolt extraction.
Click to expand...

Great content there.

I'm only a newbie to TIG also. But from what I've read so far using a higher flow rate on the gas on rounded items helps too. Or lay them into a corner of something to aid with containing the gas? Thoughts on that aspect tigrr?
 
Sorry Trev, I'm by no means a professional when it comes to Mausers, but had seen all the suggestions regarding stainless and assumed that's what the bolt was made of. After reading through the post again I see it's made with carbon.

To OP, depending on the extent of the damage the previous weld did you will be better off cutting/grinding out the affected area and rewelding it with a TIG rod of equal or greater quality than the metal of the bolt.

Trev and most others are right in what they are saying. Remove the steel from the original weld and every other part that is affected. Clean everything up nice to remove any remaining oils, lubes, blueing, etc. The nice thing with TIG is with the proper set up you can weld thin materials and "build them up". I would suggest using a rod with lots of deoxidizers.
 
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