TIG welder

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oldredford

Senior Member
  • I have a chance to buy a new, never used Miller Tig welder still in the box. At a good price... I hear so many good things about a TIG welder. Besides better control of heat to avoid warpage what other pluses can anyone tell me. Thanks to all. I am in the middle of restoring a 31 tudor sedan. All patch panels are Mig spot welded in place. Should I grind off these welds and Tig weld them in? Clueless on TIG...:confused:
 
The virtue of tig is to be able to do butt welds and have little or no grinding of the weld line. You get something akin to a torch weld, but with the heat affect zone being less then the size of a quarter or even a dime at some times.

I have learned how to make tight patch panel to base metal patches. I basically melt the panels together. The ER70-S6 tig rods have some silicon in them that helps clean the metal to let them melt together better. I only use small amounts of the rod to help the weld come together. Once the weld cools some I take off any larger bumps, usually when I mess up, and then do hammer on dolly hits to correct for the shrinkage. Then some filing to finish the level. If you did good, then you will just do a few coats of a filling primer to level.

Please remember that you can NOT avoid warpage. All welds will shrink the metal, it is the science of heating metal beyond the plastic point. Less means less area of metal that is shrunk.

You really need to understand how metal moves and shrinks to get the most out of the TIG. There are some videos you can rent from smartflix. Fender arches and Shrinking metal (or magic?) are two of the videos that you might find helpful.

Metal working hints

I also found I could weld up to the edge of sheet metal and not have any burn back, when I did not screw up. I fixed all the cracks in my hood hinge area with no burn backs and full penetration.

Once you see the magic of a TIG weld you will not go back.
 
Kevin is right, Buy it learn to use it and never look back. One way to help on the shrinkage is to hammer weld the joints. This will allow you to minimize the post work.It's tougher with a TIG because of the limited time from heat to cool off. But if you can hammer a gas weld it's very similar.


Tim
 
The metal as to be super clean and the joints should be tight, it's hard to fill gaps with a TIG. The welds are soft so you are able to hammer and dolly the welds with out cracking. I have Miller 200 TIG and I love it. If you can weld with a torch you will pickup TIG welding quickly
 
I have never seen a MIG weld on sheetmetal that looked good, always looks like a lump sitting on the metal with very little penatration. Harder than the base metal that required a lot of grinding and more heat to remove. TIG and gas welding are very much alike and the weld joint looks like the two parts are fused together. I've never had the chance to TIG steel, but spent years TIG welding aluminum bodywork, both new and old. I've been told if I can TIG aluminum I should be able to TIG steel, a friend just bought a MILLER and offered to let me try it. That is one New Years offer I plan to accept.
 
I just got the loan of a small Miller TIG welder. Just a little blue box! In your case, It's probably worth the money. However, In my case, it's a loan and has to be returned at some point. You seem to be totaly unfamiliar with TIG welding, That's good! I am not! The one thing I miss about it is the foot pedal ( Like a sewing machine) Miller has this system using a thumb switch on the side of the handle. I priced the foot pedal (it's available) for $200+. A little much for something I'm going to give back! In reading the manual, I discovered that Miller has something called "Lift start" or something to that effect. Don't scratch the electrode against the work, just touch it a pull away, Slightly! It may frustrate you at first, but you'll get the hang of it. You probably don't have the "baggage" of knowing the "old way" and having to get used to the new way. I found it worked better with a #6 ceramic cone. Good Luck with it! Oh a BTW, Why would you grind all those panels off? Just finish them up.
Terry
 
oldredford said:
  • I have a chance to buy a new, never used Miller Tig welder still in the box. At a good price... I hear so many good things about a TIG welder. Besides better control of heat to avoid warpage what other pluses can anyone tell me. Thanks to all. I am in the middle of restoring a 31 tudor sedan. All patch panels are Mig spot welded in place. Should I grind off these welds and Tig weld them in? Clueless on TIG...:confused:
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If you can't rub your belly and pat your head at the same time, you might have a little trouble adapting to TIG welding. Practice, practice and practice some more.
 
We reviewed TIG and MIG welders a while back in the Model A Times. They each have value and uses, but like everyone says buy it learn to use and don't look back!
 
For me the best thing about TIG is that you are pretty sure to get good penetration. I have made beautiful MIG welds in the past that did not penetrate and just laid on the surface. I learned that on MIG you have to concentrate and make sure that the puddle is deep.
 
A friend had let me play with a MIG on sheetmetal, I JUST DON'T GET IT:mad:There is NO control of the weld. Gas, stick or TIG the welder has conrtol of the puddle, MIG it a total different deal.
Cool Hand Lurker said:
For me the best thing about TIG is that you are pretty sure to get good penetration. I have made beautiful MIG welds in the past that did not penetrate and just laid on the surface. I learned that on MIG you have to concentrate and make sure that the puddle is deep.
Click to expand...
 
Roadster62 said:
A friend had let me play with a MIG on sheetmetal, I JUST DON'T GET IT:mad:There is NO control of the weld. Gas, stick or TIG the welder has conrtol of the puddle, MIG it a total different deal.
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Mig is the easiest of all welds to make pretty. But that doesn't mean they are strong. You are right about the others being much easier to control. Mig is great for certain things and for a Hobby guy is the best way to go. However most people who fabricate have their favorite for different jobs. I have the ability to join/weld all kinds of metal scenarios and have machines and tools to do most of them. I still prefer the old standard Arc for anything over 1/8". It's quick and no question of penetration. Gas weld on sheetmetal is pretty hard to beat especially when you add the hammer weld technique. Tig is also good for sheetmetal but the only hang up is cleanliness, a tig hates contamination and if your in a hurry or dealing with really old tin gas is much more efficient. Mig is used for tacking in hard spots or teaching the neighbor kid how to weld. I haven't used my MIG since bringing home the TIG. Not that I don't appreciate the MIG it is a valuable tool, I just forced myself to become proficient with the TIG. Brazing is also a very valuable skill to have but is more difficult than welding due to the heat and cool control needed for sound brazing. I guess what all this leads up to is expose yourself to all techniques as they all have merit and application. There is no one tool for every job, but the TIG will expand your abilities. Buy the foot pedal as the finger start can be troubling. Buy some stainless to practice on it'll build your ability and confidence fast. It's the easiest to weld with on the TIG. MAster Steel first. Aluminum is still tricky and doesn't give much in the way of color like steel does before you loose the whole puddle. Don't forget about small overlaying half circles, tight joints, and don't add too much filler rod.


Good Luck and enjoy,

Tim
 
With a MIG, you have to leave a gap between the two metals you are trying to butt weld together. If you butt them too tight, you will only surface weld. If there is a gap, it will be as strong as the metal itself.
As far as pretty goes, that comes with experience. There are hundreds of variables that will affect the strength and appearance of your welds. I'm a competent welder, but my uncle has welded for over 50yrs. What he does with a welder of any type is closer to art than welding.
 
One thing I might ask is it a foot pedal control???
Mine has a foot pedal and I use my foot to go up and down with the current level. That means you can change the heat as you go along and I think this is most important. This gives the best control. some of the cheaper units are controlled by a dial on the machine and some on the handle itself (I think NOt sure)
I will concur with everyone else once you learn to tig it is hard to go any other way for sheet metal,
Ken
 
Ken Ehrenhofer said:
One thing I might ask is it a foot pedal control???
Mine has a foot pedal and I use my foot to go up and down with the current level. That means you can change the heat as you go along and I think this is most important. This gives the best control. some of the cheaper units are controlled by a dial on the machine and some on the handle itself (I think NOt sure)
I will concur with everyone else once you learn to tig it is hard to go any other way for sheet metal,
Ken
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There's nothing cheap about my old ESAB and it has a dial on the torch and a pedal. You use which ever is most convenient. Pretty tough to use a pedal when you're on your back or on a ladder. But I guess you could "cheap-out" and hold the pedal in your non-torch hand somehow. Or maybe in your arm pit. :cool:

I've got TIG, MIG, O/A, Spot and Buzz-Box welders and it would be hard to live without any one of them. They all have their uses around the shop and property. Saying one is better over another indicates lack of welding experience or very narrow needs. Probably so narrow you don't even need a welder at all--Take the job to someone that knows how to weld. It's cheaper in the long run.
 
FWIW, The above guys know alot more about welding than I do, but on one of your questions my thought is to keep the MIG spot welds in place unless you really become proficient in tig. I took a welding class at the local JC, which was lots of fun, (arc, gas mig and tig) and wound up buying a MIG for panel replacement and spot welded them in place with a bead every inch or so across the seam on the back side and leaded in the seams on the front and they have held good, but as I say, get a second opinion from the welding guys. Again FWIW, I wanted the rear fender wells fabricated adn replaced which was over my head and took the car to one of the custom restorers around here and he said the spot welds on my panels were fine and did not need replacement or grinding down. I use the MIG now for general non-critical welding (that is, stuff that is not going to kill you if it fails, but did a modern shock mount). Tig is tough. I wanted to replace the ball on my pitman arm and the class instructor was nice enough to use it as a class demonstration project on how to use TIG up close and precise. He beveled and prepared it and you cant tell it was welded, but he of course was a pro. That is the sort of stuff I would not do and dont think amateurs should, such as shortening the pitman arm by cutting and welding. Safety is worth a few bucks. All that said, it is a fun skill and useful around the house for various miscellaneous stuff. Go for it although I think MIG is easier and more versitle for amateurs. I figure one of these days I am going to start welding sculptures and make millions doing wierd stuff and call it artistic.
 
I brought the subject of "handle switch vs foot pedal" up in the first place. (See my earlier post) The machine is on loan to me and it has only a switch on the handle. I priced a foot pedal for it and they wanted $200 Plus more. The machine was over $200 less without the footpedal. Hence, it is cheaper. Why a foot switch is worth $200 + is another matter!

In the late seventies, I used to manage the welding dept for a small machine shop. It was a one person operation, me! I ordered supplies and gas, swept the floor and I welded. We had a big Lincoln combo stick and TIG machine, and a Linde MIG. All were capable of doing every job that came in the door, beautifully! But the TIG was the nicest of all to operate. I got very used to the foot pedal! Thats what I referred to as the "Baggage". It is difficult to get used to pressing the switch and NOT being able to vary the current, for me anyway.
I haven't welded for a living since I left that job. I do have a Linde buzz box and a century MIG. but my welding has suffered a decline. I've lost my hand, so to speak. And I don't consider the Linde BB, or the century MIG, or the Miller TIG to be the equal of the earlier machines.
Terry




CCWKen said:
There's nothing cheap about my old ESAB and it has a dial on the torch and a pedal. You use which ever is most convenient. Pretty tough to use a pedal when you're on your back or on a ladder. But I guess you could "cheap-out" and hold the pedal in your non-torch hand somehow. Or maybe in your arm pit. :cool:

I've got TIG, MIG, O/A, Spot and Buzz-Box welders and it would be hard to live without any one of them. They all have their uses around the shop and property. Saying one is better over another indicates lack of welding experience or very narrow needs. Probably so narrow you don't even need a welder at all--Take the job to someone that knows how to weld. It's cheaper in the long run.
Click to expand...
 
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