Mig or Tig?

[aXLe]

I'm looking to buy a welder having not really welded before (tiny bit of Mig).

I want to ultimatly use it to weld a space frame for a car - combination of round and square tube.

For this purpose, and other general welding etc, would I be best with Mig or Tig?

I do like the look of good tig welds - is it much slower? Certainly seems to require more skill from what I've read.

Mig machines I was looking at the Lincoln 175T (240V, and here in Australia are around AU$1000). With TIG machines I have no idea - the AC/DC ones are very expensive here so I'd probably go with just a DC I guess?

Any suggestions as to whether TIG or MIG?

Thanks
Dean

[metalcaster4jc]

I'd go with the mig; it's easier to learn and a faster weld, although maybe not as precise. I've got 2 mig units (lincoln & airco) and one tig (lincoln) in my shop.
I can't say enough good about my lincoln mig unit. I 've had it for 5 troublefree years and have welded everything with it. 22 ga to 1/2" thick 4"x 4" tubing with multiple passes exceeding the duty cycle on many occasions. Even pushed aluminum wire through the whip, but had to keep the whip fairly straight to avoid kinking.
The tig unit is an ac/dc, i think 175 amps. One advantage is that it can double as a stick welder if necessary for hardfacing or specialty fill rods.

[tallwelder]

As a professional welder, I agree with metalcaster4jc, mig all the way for a novice welder! Tig can be performed with just a short amount of practice but until You learn what You are seeing, it could just appear to be welded correctly. I have also owned a lincoln mig machine and enjoyed many years of troublefree use!

[NC Cams]

Having done both, there are times when tig is more appropriate (control, heat, material) and others when mig rules (welding stock car or car trailer chassis).

Mig is a bit easier to learn because all you do is point and shoot PROVIDING you get your heat and wire feed settings correct. Once you do this, you simple weld away.

When you get into confined areas or are doing finer material, a TIG can be more appropriate. If you do go TIG, step up and away from the "scratch" type and spend the buck for the high frequency type with the foot control. Enables you to adjust "heat" on the fly which is critical as parent metal temp starts to climb.

If you're welding mild steel most of the time, mig is perfectly adequate. Yes, you an weld aluminum and stainless with mig with proper wire and gas.

BUT for really pro stuff, tig is what the professional fabricators I worked with chose for EVERYTHING except high volume chassis/structural fab type stuff. Most of the precision "Biker Buildoff" stuff done on TV is tacked with mig and finished with tig (easier to get perfect ringlet welds).

[Mcgyver]

Dean, I'm a light weight in the welding area, but faced with the same decision have observed and asked a lot and consistently get ..

5) the serious guys have both
4) TIG is the most versatile
3) TIG is the most expensive (not just capital cost but per weld)
2) TIG is preferred for thinner sections, MIG for thicker
1) TIG is harder to do well (many recommend taking a course which i've never done for shop work but would seriously consider for TIG welding).

As a home shop guy, the flexibility TIG gives is appealing. I am O/A welding everything in sight these days as many peeps have told me that is a good training ground for TIG - its all about puddle control!

[pstockley]

Being involved with a race team and having built a chassis, I would recommend MIG. For a novice, TIG is ok if you can sit down and use a pedal control. On a chassis it can be really difficult and often you need to use a hand control which is harder. Having said that, we usually TIG'ed all the critical stuff such as A-Arms, steering shafts etc. Now if you are using 4130 most people use TIG and normalize the welds afterwards.

If you are really serious and don't mind putting in 100's of hours of practice, TIG is more flexible. If you go this route, get an AC/DC inverter, they are nice and small and very flexible.

[Kevin Taylor]

Having been welding for thirtyfive year's I think that I could give advice in this dept. If you want to build demo cars or stock car's the mig is ok but you might consider that you may be the only one with a tig welder in the neighborhod and that has it's good and bad aspects. Mcviger is right it takes more of everthing to tigweld especialy patience Gas welding is a easy transition to tig but dont get used to mig and then think your going to tig . My oldest son is self taught mig welder and can hold his own but the tig welding takes a lot of time for the amount of weld produced. Light materials such as sheetmetal can be easly welded with the tig with min distortion. The aluminum end of couls be a money maker aswell also stainless I built my third of fourth race car with a lincoln AC/DC buzbox with a add on Hifrec and a aircooled tourch no foot control now I have a 300 amp miller sincrowave with foot control palser ect it has more stuf than a cellphone to program and it's ten year's old now. Go to the library or to the book store at a local trade school and get a text book and read up before you go visit your local welding supplyer that way he won't leave you with a deer in the headlight's expression on your face and you wont be talked into something you cant use , want or need. Good luck Kevin

[aXLe]

Thanks guys - some good feedback there. I'll do some more reading up, but am tending towards the MIG to get started with.

[wizard]

Originally Posted by aXLe I'm looking to buy a welder having not really welded before (tiny bit of Mig).

Your not the only one looking! Do consider the limitations of the electrical service to your area of usage. This is one issue I have. Just don't let it become such a concern that you artificially limit your choices.

I want to ultimatly use it to weld a space frame for a car - combination of round and square tube. For this purpose, and other general welding etc, would I be best with Mig or Tig?

Well first realize that my practical experiences where gained twenty some odd years ago when I was using welding equipment at a place I worked. That out of the way, I don't consider either Mig or Tig to be general purpose processes. The vast majority of the welding I did was with stick, later we got a giant mig welder. My impression is that a mig welder is not a general purpose machine. However welding tubing that you describe might be a good fit. As to Tig that was considered even more specialized and was left to the die repair shop.

I do like the look of good tig welds - is it much slower? Certainly seems to require more skill from what I've read.

This goes agianst the grain here a bit, but I'm of the impression that stick welding is a far easier technique to learn. Of course I was at the time working on heavy industrial machinery and growing up farm machinery.

Mig can be easy to operate but that shouldn't be confused with getting a good weld.

Mig machines I was looking at the Lincoln 175T (240V, and here in Australia are around AU$1000). With TIG machines I have no idea - the AC/DC ones are very expensive here so I'd probably go with just a DC I guess? Any suggestions as to whether TIG or MIG? Thanks Dean

Well here is my suggestion which probably should be taken with a grain of salt. I'd invest in a good welder that can handle both Tig and stick welding first. (note the word "first") This of course assumes you will take the time to learn proper operation of the machine.

The reasons are as follows:

First stick welding is general purpose in my estimation and should be the starting point in skills development.

Second Tig affords you better control with thin wall sections. Further I see Tig as the easiest way to follow the odd joint lines that you will get with the intersection of tubing.

It is interesting that your question should come up now as the plant I'm curently working in has recently installed a lot of pipe! While I didn't have time to investigate to closely, it looks like all of the stainless steel process pipe was done with a Tig welder. The heavier steam lines and such where done with stick. No Mig to be seen anywhere. This of course is work done by professional pipe fitters and welders.

As a side note I'm looking for a welder my self. The service at my house is limited thus I'm looking at Mig and inverter based Tig/Stick machines. As you have noted the inverter based machines are not cheap at all. If I go this route I want wide voltage input and portability too. This means looking a Miller welders. The other options is a welder/generator Gas power machine. So I share your problem of figuring out the proper route to take, though I have differrent constraints. I'm convinced though that a Tig/stick welder is far more versatile than a Mig welder.

Thanks
Dave

[RMS]

I started out with stick welding, I have 5 welders now. I love my Miller tig welder/stick welder. You could do that Chassis stuff with 7018 3/32 wire its awsome stuff! Get a used - mid sized tig welder most will be able to stick weld too. If you can't see this as an option then I would say go with MIG, I like Miller myself but also like Lincoln, and Hobart.

STAY AWAY FROM THE OLDER USED LINDY MIGS.

Now if you are going to use mig for critical rollbar aplications make sure to talk with the supplyer of the consumables to get the right wire and gas/mixture for the steel/alloy tubbing you are welding.

One bad thing about critical MIG welding is that it can be finiky/tempermental if joints are not preped properly, a weld can look good on the surface but have perosity/holes on the inside one crash with this type of weld and it will snap right off. 7018 3/32 Stick is more forgiving NOW at the same time if MIG is done right it will be fine.

[DSL PWR]

I just bought a Lincoln 185 Tig box, and I love it. The pulser is great for out of position welds. I need a water cooled torch, I can only weld about 18 inches before I can't hold the torch! The PWM on the ac is also a great tool. I still need to master welding pop cans together...

Any way, is there any reason why you couldn't use a tig box to run a suitcase mig? I know they make suitcase models that will run on CC which is what the tig puts out. If a suitcase model would work, could it be used in AC for aluminum?

Another thing I want to try is to run Hi freq using a stick electrode. This would make an arc wickedly easy to start... right?

[CNC Pro]

I too am working on a small car project.
I purchased a Mig welder, tube bender and notcher with the intention of using drawn tube steel. While the Mig works well (point and shoot), I’ve found that trying to weld with small diameter tubing takes some practice, and doesn’t always give the finish and control I’m used to with gas & stick.

My new design is leaning towards an aluminum monocoque design, as I’ve been having good results cutting aluminum on my CNC routers. I know that I’m going to have to look at a large Tig with cooling & long duty cycle to handle the heat and long run time.