MIG Versus TIG

I learned with Oxyacetylene, and I'm glad that it was all that I had for many years.
Brazing us under rated as well - it can be quite beautiful and strong.

Stick welding is cheap and simple. It used to be the standard go-to method.
I've done flux core wire welding, and it's like stick-lite, IMNSHO.
I setup my welder for MIG, but still haven't used it... I have a lot of flux core wire, so I keep using that.
TIG looks like fun - especially since I like Oxyacetylene welding so much. Someday I'll try it.
None of them are good or bad - each has advantages, and is usually better than nothing.

Mark_42 said:

None of them are good or bad - each has advantages, and is usually better than nothing.

Now there's advice you can take to the bank.

Welding is usually better than not welding.

In reply to NOHOME :

I’m familiar with purge welding. We do it on sanitary piping on a regular basis. Probably one of the hardest forms of welding to learn...

I have mig, tig, stick and gas. Different horses for different courses.

For those that are hobbyists and usually poor or broke I suggest gas. Everything I have was free or very cheap and has paid for itself 10x over... Maybe this varies by region but this stuff gets thrown away because no one takes it off the free Craigslist ads or yard sales asking pennies on the c note of initial costs. 

Don't believe it browse Craigslists for torches. Most people can't even identify this stuff

No angry emails.  We just like to tell you why your wrong .  We strictly use a TIG  here in our facility to help construct a certain precision device mentioned in a certain sci-fi empire tv show (though primitive from their perspective).  

Jere said:

For those that are hobbyists and usually poor or broke I suggest gas. Everything I have was free or very cheap and has paid for itself 10x over... Maybe this varies by region but this stuff gets thrown away because no one takes it off the free Craigslist ads or yard sales asking pennies on the c note of initial costs. 

Don't believe it browse Craigslists for torches. Most people can't even identify this stuff

I was going to bring up cost of MIG v TIG, especially considering the nominal stuff we weld.

But you beat that argument.  I wish I learned how to gas weld- as it's one of the most robust things to learn.  Instead, my wife bought me a MIG, which I love to use.  For a pretty nice 110 welder- it's 1/2 the price of a TIG one, and it turns out that the odds of me actually needing TIG specific welding is still on the zero line.  I've needed brazing skills more than TIG.

No doubt in my mind the greatness of TIG welding- none at all.  I have see work of art welding on that, too.  Just that even the mild steel I do weld, it would be a pain.

Anyway, the the best answer was already posted- it depends- all have their advantages, all have thier compromises.

As a metal fabricator and welder of forty years, with time as a welding instructor, I have some nits to pick with this article.

AC is used on aluminum not  for "dirty" metal, but to remove the non conductive aluminum oxide that forms on aluminum  (in minutes). You can weld TIG aluminum with DC current(reverse polarity) so long as the material is thin and you use a heavier than usual electrode.

Shield gas doesn't clean anything, it protects the molten metal of the weld from oxygen in the air, that would react with  (oxidize) the molten metal, destroying it's mechanical properties.

The fast cooling of a MIG weld is rarely an advantage. Harder, more brittle steel isn't generally a good thing in a welded assembly.

The flexibility and controllability of TIG cannot be overstated. I can weld the aluminum foil off a gum wrapper with  the same machine I can TIG braze 4130, or weld titanium, or fix a trailer hitch. Changing from one setup to another takes just minutes.

When you pull the trigger on a MIG gun, you are committed, if the machine isn't set up right for that joint, you are out of luck. If you don't have a tIG machine set up perfectly for that joint, you can  often compensate  mid weld, or stop and readjust the machine, with no problems. Screw up  the setup on MIG, and you'll be grinding away a weld. Test setups? Sure, but you don't always have that option

The flux in flux core or stick welding does have some "cleaning" affect, in that it ties up surface contamination to be chipped off as scale when cool, but it's primary function is to keep air away from the hot metal.

MIG is only faster than TIG if you don't care much about looks. Any part that will be visible or painted will require post weld finishing if MIG'd, not if TIG'd .That usually more than sucks up any time saved during the weld.

It's much harder to make a MIG joint as strong as a TIG joint, and very  much harder  than most guys realize. MIG joints can look good but penetrate very poorly (weak and prone to fail), a good looking TIG weld will rarely fail.

MIG is for when your welding is measured in feet of bead per minute. TIG is a better method for most strength critical applications, which, IMO, is anything on a car.

Including roll cages. Most of the time spent on a cage is cutting and fitting tube, not in the welding, even if you TIG.

It's not hard to learn to TIG, I've taught women who have never worked with metal at all, to TIG aluminum  in less than four hours, stainless in two. Guys generally take about twice as long, they aren't as good at listening.

I know it's fun to endlessly discuss and argue the various minutia of welding, but I'm going to suggest the following with pretty much 100% confidence:

For home welding and engineering: so long as you get the two pieces of metal melted together with roughly the right filler metal, it doesn't matter what process you use or how it looks.

There are so many other unknowns and odds are that your design is so overbuilt (or underbuilt) that it'll never matter that ER70 MIG might fail at 5x10^5 fully reversed cycles vs 2x10^6.

Flux cored MIG all the way!

They are, of course, different in terms of ease of use and aesthetics.  But in terms of "will it break if I do it one way or the other" none of that is really the critical factor in our home brew designs.

I've read a couple of these articles now and don't see many people talking fumes and cancer. There is enough scientific evidence that welding causes a couple of different types of cancer and the UK has mandated workplace rules around venting the fumes and wearing respiratory equipment. 

https://www.hse.gov.uk/safetybulletins/mild-steel-welding-fume.htm

From memory, TIG welding creates less fumes but proper venting and a respirator are still necessary. Is this an over-reaction for the home hobbyist? Maybe, but lung cancer is a bad way to go and I'll be setting up a vent system and using a mask when i get around to buying a TIG.

I talk about this with my metalwork students whenever we go through another welding process.  You don't notice the smell much when you are doing the welding, but others sure do.

I don't always use a filtered mask when welding (I should), but do if it's particularly smokey.

Flux-core MIG is SMOKEY.  I don't like it.

Stick is smokey.

MIG is still reasonably smokey.

TIG isn't bad - I know my helmets don't get as skanky as quickly if I'm doing a lot of TIG.

Keep in mind the metals are contributing to what you're breathing, it's not just the process.  A lot of the alloys in steel and stainless and aluminum are not good to breathe.

But also keep in mind sanding and grinding dust, as well as the abrasive material you are breathing in as well. 

I'm going to be building a downdraft welding/grinding bench soon to help control this crap.