Gas, MIG and TIG: Best For Which Uses?

[HawkRod]

So I am a novice welder, but trying to learn. Like anything it takes practice. Currently I have a gas and a MIG welder.

I use my gas mainly as a "hot wrench" on stubborn hardware and also to heat up metal cherry red if I need to bend or shape something. Rarely, but sometimes, to cut metal. I really have not welded with it.

I use my MIG for welding stuff together. As I said, I am a bit of a novice so my results vary, but that is just practice.

Can I ask the welders on the forum: What type of welder is best for what types of situations? I see now a lot about TIG welding, so is this preferred in general over MIG? And is TIG welding much harder than a MIG? Pros and Cons?

Thanks in advance!

 

[MoparLeo]

TIG like all welding relies on good technique. Gas welding is the weakest of the three. Generally used in low stress areas like exhaust systems or cutting ( with the proper cutting torch attachment) . Brazing, soldering etc... Must be careful not to overheat parts that require temper as heat severely weakens metals. Also open flame is more of a fire hazard so you should always have someone to keep an eye out for this when you are using it. Like any welding a must is having the proper fire extinguisher(s) on hand.
MIG is next. Easiest to learn. Generally limited to Ferrous welding ( Aluminum is possible with additional accessories) and thinner metals at home.
TIG Used for more types of materials, very easy to focus heat. Needs very clean metals to give best results. Basically fusion welding wih minimal filler required.
As with any acquired skill, get lots of scrap metal and practice, practice, practice.

 

[747mopar]

The reason guys like TIG over MIG for sheet metal is it produces a softer weld. As you weld the metal shrinks at the weld pulling the metal in causing warpage, the softer TIG weld can be dollied down to counteract the shrinkage where MIG is a lot harder. Gas welding also produces a soft weld but can really add a lot of heat causing even more problems if you don't know what your doing. There's a guy here in town that does all of his welding with gas on his hotrods and does some really impressive work. MIG of course is the easiest and handiest especially in places where feeding with one hand while welding with the other is difficult.

I've had good luck with MIG but have also warped alot of stuff in the process, you have to be more patient and knock the welds down as you go. When I smoothed my firewall it lent itself nicely for TIG (easy to work the pedal and use both hands while sitting), that was the best results I've had as far as the metal being easy to dolly and smooth out with almost no filler.

Yes TIG is harder, I tend to use both hands when I MIG for better stability but you can kiss that goodbye with TIG. Like anything else it's practice but TIG gives you a lot more control, you decide how much filler goes in and you can fluctuate the amps as needed.

 

[snakeoil24]

So far above is good I would add that Mig is porous and Tig is not. Tig is like Gas Welding takes time and patience to learn.

 

[Photon440]

So far above is good I would add that Mig is porous and Tig is not. Tig is like Gas Welding takes time and patience to learn.

Mig isn't necessarily porous; if you have a dirty surface, rust, paint or grease, yes you can get porosity. If you're not using enough shielding gas, same thing. But when done properly, the weld is solid. I welded up compressed air lines and fittings for brakes on trains for years, zero leaks allowed in a 90 psi. system.

 

[VANDAN]

Hawk, I Love my Miller 211, for an All Around Machine ! Prep & Process is the key, along with the "Touch"...

 

[snakeoil24]

I find with the best shielding co2/Argon at 1- 15 psi Mig is still porous

 

[Photon440]

Your flow meter should be between 30 - 40 cubic feet per hour, in still air conditions.

 

[Nate S]

For me I like TIG because I can reflow etc without adding more metal. In particular for sheet metal butt welds I find it easier. Always seems to end up cleaner too. Like anything of this sort, I'm quite sure there are many who have the opposite take on the whole deal.

 

[HawkRod]

Thank you all for the helpful replies! I currently have two welders and limited space, so I am trying to determine if I should take the plunge for a TIG welder. I don't do enough welding to get proficient on both, so I'm trying to decide if I should stay with MIG as I have partially learned that or jump to TIG instead. I know there are some units that can do both MIG and TIG welding. Maybe I need to save some money to buy that type of unit?

Hawk, I Love my Miller 211, for an All Around Machine ! Prep & Process is the key, along with the "Touch"...

Ah, yes, the "touch". THAT is what takes time to learn and get right, at least for me! I am still in that learning phase with my MIG at least.

 

[747mopar]

I guess my simple answer would be a TIG but... TIG is more limiting to getting into those hard to get spots. It's not fun to weld an exhaust in place with a TIG or getting inside a rocker, etc. If you go with a TIG just keep a little 110V MIG around, I do everything car related with my Lincoln SP135 and it's very small. You could even make a welding cart that holds both.

 

[HawkRod]

I guess my simple answer would be a TIG but... TIG is more limiting to getting into those hard to get spots. It's not fun to weld an exhaust in place with a TIG or getting inside a rocker, etc. If you go with a TIG just keep a little 110V MIG around, I do everything car related with my Lincoln SP135 and it's very small. You could even make a welding cart that holds both.

Thanks. I do have a small welding cart with a 120V Craftsman MIG unit I bought maybe 8-10 years ago (not sure what unit they slapped their name on). I have shielding gas with it too. It works fine for most of the stuff I work on. Perhaps the biggest issue isn't the welder, but more so that I need more practice. When I welded some valve covers I found that I blew through the metal in a few spots. So I have struggled with thin metal welding. I guess this is just an experience thing...

 

[747mopar]

Thanks. I do have a small welding cart with a 120V Craftsman MIG unit I bought maybe 8-10 years ago (not sure what unit they slapped their name on). I have shielding gas with it too. It works fine for most of the stuff I work on. Perhaps the biggest issue isn't the welder, but more so that I need more practice. When I welded some valve covers I found that I blew through the metal in a few spots. So I have struggled with thin metal welding. I guess this is just an experience thing...

Wire size is very important, the heavier the wire the more amps it takes to make it lay in smooth. I run mostly .023".

 

[Mike67]

I bought the Lincoln 200, seems to be more than I'll ever need in a small package.
I havent spent a whole lot of time playing with it yet but am pretty happy with it
I know there are cheaper models out there but felt this was a good compromise @ $1500.

 

[Mike67]

Just did some searches and saw this...thinking about buying it just to have a throwdown...
https://www.jegs.com/i/JEGS/555/81542K/10002/-1

 

[Jeff Peterson]

Just an FYI, if your going to weld aluminum, you need an AC/DC unit.

 

[451Mopar]

Sounds like you have some equipment. What are you trying to weld?
What steps are you taking to learn to weld?
Most machines will weld carbon steel pretty good. TIG is nice for welding aluminum, stainless, and such, in addition to carbon steel but it gets expensive.
I started like many of us doing gas, stick, and mig with very little training and could get decent results after some practice (or so I thought.)
About 10 years ago, I finally went to welding school at night (Lincoln Tech, Denver), and learned quite a bit that I wish I knew when I was just starting.
Also, most of the 4-hour per night 4-day/week class was practice (about 50+ hours a month?)
It would be nice to say, just take the classes, but they were really expensive (I think around $15K.)
There are a bunch of good you-tube videos to learn from also. The problem is how do you lean a weld process without the equipment?

 

[ckessel]

I have all 3. Gas I use just for heating or soldering heavy cable. Example: battery cables. Wire for most fabrication or doing spot welds ahead of full tig welding. Tig for sheetmetal, important structural, aluminum, stainless and some other stuff. When using tig on steel, you can't be using hot rolled steel as it spits like the 4th of July from the outer coating. You can sometimes grind through it but I've had times when it still spit. Better to use cold rolled or what's called PNO which means pickled and oiled. And yes you need an ac/dc unit to tig aluminum. Tig is the slowest process too. You use both hands and one foot to tig. It would be beneficial for you to take a welding class that covers mig and tig. tig takes some doing to nail it down unless you are one of the lucky mofo's that master it like they have done it all their life. In the class I took, there were some kids[ I was in my late 50's, they in early 20's] that had never done it and did quite well. Made me envious. I can do it decent but need lots of time doing/practicing. Kind of like shooting. Have to do it a lot to stay proficient. Of course unless you are a lucky mofo.

 

[HawkRod]

Wire size is very important, the heavier the wire the more amps it takes to make it lay in smooth. I run mostly .023".

I'm running .025". I had thinner wire before the .025" and I actually think I had slightly better results with it.

Just did some searches and saw this...thinking about buying it just to have a throwdown...
https://www.jegs.com/i/JEGS/555/81542K/10002/-1

My knee jerk reaction is to say I need a TIG machine, but I think perhaps I should get proficient with MIG first.

What are you trying to weld?
What steps are you taking to learn to weld?

I still need to finish up some valve covers to weld a baffle in them. But in general, I am merely trying to understand the pros and cons of each type of welder. Most of my welding is car hobby related, and based on some of the responses here, MIG does a pretty decent job for most of those needs.

tig takes some doing to nail it down unless you are one of the lucky mofo's that master it like they have done it all their life.

Yeah, the lucky mofo - that's not me!

I can do it decent but need lots of time doing/practicing. Kind of like shooting. Have to do it a lot to stay proficient.

I think practice is likely the key. I have had times when I was quite proud of the welding I did, and other times when I really struggled.
I have watched a few videos on YouTube and a couple were really helpful. But I guess I need to spend more time with the welder to hone some of those skills.

 

[ckessel]

Tig takes some time to master. Unless it looks like you sleep with it like some of those kids. Thats what I would sometimes ask them. I think the best bang for the buck is to take some classes. I'm pretty good on mig but the class still helped as I had no formal training, just learn by doing. Stick I have no use for but that was the first part of the class. Once the class was over for the semester, I signed up for the tig only class. I actually do better on aluminum than steels on tig. I guess its easier for me to see the weld pool since the amps are up. If you have old eyes like me, have a harder time seeing without the need for more light, then you'll need to find a good helmet. I used the Miller unit but it blocked too much light on the weld pool so I had a tendency to cook ferrous metals. Currently I'm using a helmet from Optrel, the E684 unit which was a step up in view from my Optrel Vega View unit. Now all I have to do is get my left eye lid spasm's stopped so I can see with both eyes open as opposed to one open.