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Old 12-15-2012, 10:10 PM   #1
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Default MIG/TIG questions

1) For a beginner that has no intention of ever going to a welding class, would it be foolish to buy a TIG?

2) Because I'm a hypochondriac, is TIG better for your health in terms of smoke, fumes, noise etc?

3) What makes TIG so much more difficult than MIG? When I watch videos, it looks easier than MIG so I'm missing something.

4) What's a good beginner TIG machine, that will also suit me later in the future as I improve? Are there 110v ones that can be converted to 220v?

5) What would you choose b/t the 2 as your ONLY machine? Mainly automotive stuffs (manifolds, DPs, exhausts, etc), but would like versatility as well (door gates, home improvement, carts, etc)
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Old 12-15-2012, 10:26 PM   #2
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If you have good manual dexterity and don't mind cleaning everything very well before you weld, Tig really is not much harder. It's slower though. Tig is very difficult for me because I have very shaky hands.
MIG is generally less sensitive to contamination but still important that everything be clean.
If you are worried about fumes you can buy filtration masks that work pretty well.

I'd say get a nice TIG machine and a cheap flux core/mig for fixing gates/carts/home improvement type of stuff.
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Old 12-15-2012, 10:26 PM   #3
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1.) No, any welder has safety issues and needs a starting point to learn, most classes start with stick and arc welding, then wire. After you learn how to do both, everything else is nothing but a level up. TIG is more expensive to run though, and both MIG(unless its flux-core) and TIG need more prepping since it has no flux.

2.) TIG and MIG both have the same health risks in terms of fumes, but most of the fumes comes from what piece you are welding. Just need a well ventilated area, and proper cleaning of the item you are welding if possible. Wearing a respirator is always a plus.

3.) TIG uses a metal rod that you have to feed in by one hand, and control the heat; it makes the weld process two-handed. MIG feeds wire into the heat source, but TIG is always stronger due to arc penetration.

4.) I wouldn't trust a 110v cheapo for TIG; if you go TIG, go 220v. The most common names in the welding industry are probably Miller and Lincoln.

5.) I personally would go MIG ( currently have a flux-core due to lack of 220v) because its more versatile when moving the machine. TIG and outdoors dont seem to get along. MIG does a bit better than TIG outdoors because it feeds directly so you can get closer to your weld. You can also control a MIG machine with the "gun" vs. a TIG machine is foot peddle controlled., but for out doorsy stuff anything with a flux is better. Argon's enemy is wind.
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Old 12-15-2012, 11:39 PM   #4
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TIG is not always stronger due to arc penetration. Provided neither weld has any defects, MIG and TIG will produce the same weld strength provided the fillers are comparable.

That aside, if I had to have one or the other, I'd opt for the MIG unit from a versatility perspective. I have both, and for speed and simplicity, I prefer to use the MIG more than I do the TIG unit, even though I prefer TIG welding in general (probably because it keeps me in the garage longer, and therefore, drinking more beer.)

Initial expense will also be less for a decent MIG unit. Be prepare to spend at least $2k for a TIG unit worth spending the money on provided you want AC capability.

Also, if shopping for TIG units, don't be deterred by the lack of a pulse feature. There has been nothing to this day that I have ever needed to weld using pulsed GTAW.
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Old 12-15-2012, 11:51 PM   #5
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I paid under 1500 for my TIG, in Australia, i imagine that would cost under 1k in USA.

It pulses and the pulse feature means you can do extremely nice visually pleasing welding on fine materials for exhausts and for inside engine bays.

Dann
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Old 12-16-2012, 12:59 AM   #6
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Quote:
Originally Posted by Supe View Post
TIG is not always stronger due to arc penetration. Provided neither weld has any defects, MIG and TIG will produce the same weld strength provided the fillers are comparable.
I will have to disagree with you seeing how we had this same arguement with our weld shop instructor during a metallurgy electron microscope class.

A MIG will pile up wire and not penetrate at all if the amp and speed isnt set properly. A TIG will not fill until its hot enough, you can also apply more heat in a smaller area before filling with warping the whole piece, which is something you cannot do with MIG. I have a picture somewhere from that same day of the two different welds in my books from 2008.

A TIG also can weld more different types of metal, along with welding really thin gauge metals without using filler rod.
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Old 12-16-2012, 01:12 AM   #7
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I do 1.2m exhaust all the time filler free. Gets plenty of penetration and looks gorgeous.

Dann
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Old 12-16-2012, 01:31 AM   #8
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Ewm alpha q
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Old 12-16-2012, 09:29 AM   #9
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Kenzo you need to go check out the custom fabrication thread and the DIY Manifold threads, there has been a lot of good welding advice in there recently. I am just starting to learn to weld and I am starting with TIG. I had planned on starting with MIG, and eventually moving up to TIG. Fortunately a used Lincoln Squarewave 175 TIG machine popped up on CL locally and I had to jump on it.

Is there a reason why you say you will not take any classes? I signed up for a TIG class at my local community college. It falls under their continuing education program and is on Saturdays. It is a few hundred dollars and only a month long. I figured that while yes I can learn how to do TIG on my own, having an instructor that actually teaches me to do things correctly can only help.
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Old 12-16-2012, 11:29 AM   #10
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Quote:
Originally Posted by Pen2_the_penguin View Post
I will have to disagree with you seeing how we had this same arguement with our weld shop instructor during a metallurgy electron microscope class.

A MIG will pile up wire and not penetrate at all if the amp and speed isnt set properly. A TIG will not fill until its hot enough, you can also apply more heat in a smaller area before filling with warping the whole piece, which is something you cannot do with MIG. I have a picture somewhere from that same day of the two different welds in my books from 2008.

A TIG also can weld more different types of metal, along with welding really thin gauge metals without using filler rod.
And a TIG weld will also have lack of fusion if the amperage is too low, or you're using too large a filler metal diameter, or if you've got inclusions from not removing silicon deposits between layers (and you don't set amps with GMAW process, you set volts and wire feed speed, the latter of which dictates your amperage).

Regardless of what your shop instructor said, I've performed over 1000 welding procedure qualifications in my lifetime, and I can tell you this - there is no discernible difference between a weld made with a 70 series electrode whether it be made with GMAW, GTAW, SMAW, FCAW, or any other process when it comes to ultimate tensile strength, provided the welds are defect free.

When it comes to heat input, you typically get LESS distortion with GMAW than you do with GTAW, because you can run faster travel speeds and finish a weld with fewer passes, resulting in lower overall distortion. This is the reason why the pulsed GMAW process is being used to weld the vast majority of structural steel in new nuclear power plants, on everything from carbon to low alloy to duplex steels.
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Old 12-16-2012, 02:54 PM   #11
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You are the only welder in the world that believes that tig will warp more things than wire, out of all the top people in AWS I have personally met with more than 1000 hours. The reason you say that fewer passes are needed because its a constant feed, the MAIN reason it is used most commonly in construction is because of its versatility, price, and ability to fill large prepped areas. I can't imagine anything being built building-wise if everything was tig. Your only arguement revolves around preparation, which is a known fact that it has to be correctly prepped for any tig weld in the first place; if its not prepped, that is the welders fault, which is what is needed for both processes; so why argue the fact already stated?

When it comes to construction and LARGE area welds and overall cost, yes mig is where it's at. If a construction site had ALL THE FUNDS, they'd probably go spray arc and call it done.

But for precise, superior quality, low warp, strong welds with full control in a closed environment and really thin pieces or precise machined pieces of different metals, tig is where its at.

Also, an experienced welder can easily compensate for large diameter filler rod.
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Old 12-16-2012, 05:48 PM   #12
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You are the only welder in the world that believes that tig will warp more things than wire

Pretty bold statement, have you personally asked all of them? How about welding engineers, do they all agree with you as well?,

out of all the top people in AWS I have personally met with more than 1000 hours 1000 hours of what? How does that have anything to do with qualification of welding procedure specifications? I've met a lot of the "top people in AWS" too, seeing as I serve on the D10 committee (including D10.17 for tubular vehicle structures), in addition to D1.1 and D1.6 task groups, and I'm confident I can find quite a few who would be inclined to disagree you on these issues..

The reason you say that fewer passes are needed because its a constant feed so are automated GTAW processes, which typically still result in greater overall heat input than a GMAW equivalent,

the MAIN reason it is used most commonly in construction is because of its versatility, price, and ability to fill large prepped areas. I can't imagine anything being built building-wise if everything was tig. Your only arguement revolves around preparation, which is a known fact that it has to be correctly prepped for any tig weld in the first place Actually, my argument stems from the fact that GTAW typically produces greater distortion than GMAW, and is due to a greater overall heat input that results from slower travel speeds and the shrinkage of multiple weld passes. And in both the environment I work in, as well as my garage, the joints are prep'd the same regardless of process; if its not prepped, that is the welders fault, which is what is needed for both processes; so why argue the fact already stated?

When it comes to construction and LARGE area welds and overall cost, yes mig is where it's at. If a construction site had ALL THE FUNDS, they'd probably go spray arc and call it done GMAW is cheaper on both a home and industrial scale, though I'm not exactly sure why this is being brought up in the first place.

But for precise, superior quality, low warp, strong welds with full control in a closed environment and really thin pieces or precise machined pieces of different metals, tig is where its at.

Also, an experienced welder can easily compensate for large diameter filler rod.

I'm really not going to get into an internet pissing match here. You made a few statements that you've declared as fact, and I'm offering a rebuttal for those who wish to investigate themselves.

It was stated that TIG welds are stronger than MIG welds. And, if there are no weld defects, then that is an untrue statement, as your process isn't going to change the UTS of the filler metal. The logic you provided was that this was based on MIG settings not being adjusted correctly, and the same can hold absolutely true for TIG (it's easy to wet out the toes with GTAW on a fillet weld have have no penetration at the root). To say that TIG welds are less predisposed to having weld defects that can impact the strength of a weldment perhaps would have been a more accurate statement.

It was also stated that GTAW distorts less, and while that is sometimes the case (typically where GMAW is not conducive to achieving weld sizes that small), more often than not, it is incorrect, as a function of both total heat input and weld shrinkage among others.

GTAW is a great process, and is selected because it's a low hydrogen process that is easy to control and is less prone to the defects typically associated with flux processes. I'm just suggesting that increase strength and low distortion are not typically two of the items associated with the process.

Again, my intent here is not to get into a pissing match, only to help inform. I think there's a bit of a fundamental misunderstanding on some of these subjects, but if welding and metallurgy were easy, there'd be a lot more welding engineers out there! Granted, it gets even more intriguing when you talk about the processes and materials we typically deal with in a racing environment, where cooling rates and dilution can play a much bigger factor in process and filler metal selection. I will say that some of the NASCAR boys are doing some pretty cool stuff with pulsed GMAW these days, especially with the RapidArc process that Lincoln Electric developed.

Anyways, enough hijacking of the OP's thread. I talk about this enough during my normal 10 hour work days!
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Old 12-17-2012, 08:53 AM   #13
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Quote:
Originally Posted by Pen2_the_penguin View Post
I will have to disagree with you seeing how we had this same arguement with our weld shop instructor during a metallurgy electron microscope class.

A MIG will pile up wire and not penetrate at all if the amp and speed isnt set properly. A TIG will not fill until its hot enough, you can also apply more heat in a smaller area before filling with warping the whole piece, which is something you cannot do with MIG. I have a picture somewhere from that same day of the two different welds in my books from 2008.

A TIG also can weld more different types of metal, along with welding really thin gauge metals without using filler rod.
Short circuit sure.

See: Spray transfer.

Also, pulsed Mig welding is a thing now look it up. FWIW i do 90% of the aluminum at work with a spool gun on the mig. It's faster, easier, and produces just as good of a weld.
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Old 12-17-2012, 10:44 AM   #14
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Quote:
Originally Posted by nitrodann View Post
I paid under 1500 for my TIG, in Australia, i imagine that would cost under 1k in USA.

It pulses and the pulse feature means you can do extremely nice visually pleasing welding on fine materials for exhausts and for inside engine bays.

Dann
I just paid 1800 for an entry level unit, miller diversion 180. I could have gotten the 160 for a little less than 1500, but I wanted the 110/220 versatility, the digital controls, the extra amperage, the foot pedal. Both diversion units come with hand controls on the torch, I've never used hand controls, so no comment. I havent used the welder yet, but it uses the default settings from the miller dynasty, which is a welder I have used. I've only run into problems using that machine when the high frequency breaks (and the shop manager swears its still fine ), and when someone changes the settings. You can get an eastwood tig for 800 with a decent helmet and some glove, I went with the miller because I've used them before and I know is a solid brand that stands behind their machines. The eastwood sure looks good when you compare the stat sheet, but theres more to a welder than the stats sheet.

More to the op, I cant mig to save my life I constantly flash the wire up in the copper guide thing. I do know they make more smoke than tig, or at least more of it stays around the weld. Because there is less smoke around the weld with tig, less light is diffused by the smoke so the weld arc appears brighter. You can buy welding helmets with a total seal so light cant reflect in the back, these also have ventilation systems with filters. I believe 3M has the go to setup for those right now. I know someone who has one, we make fun of him behind is back, but I'm a little jealous. Having cool clean air blown on your face under the helmet would be awesome when welding in the summer.
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Old 12-17-2012, 11:12 AM   #15
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ESAB tig > Miller tig.

That's coming from someone who uses all Miller prodcuts at work, and has a personal Miller at home.

I think i'm going to buy a ESAB tig machine when i can affod one.
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Old 12-18-2012, 02:02 AM   #16
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Are these bottles really $140 each?
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Old 12-18-2012, 02:15 AM   #17
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sounds right to me.


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Old 12-18-2012, 02:27 AM   #18
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Why do they cost so much? And do I really need 2?
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Old 12-18-2012, 02:33 AM   #19
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GMAW will be sufficient for all your welding needs. Its more universal than GTAW. Fabricating sometimes with GTAW can be tricky esp when you have to hold a part, feed rod, and actually produce a solid tack. Where as GMAW you hold and buzz and your good to go.
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Old 12-18-2012, 02:49 AM   #20
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Yo Kenzo. First of all, yup the bottles are pretty expensive, but you should be able to find a welding store around that you can basically return the tanks for the purchase price or trade them in if/when you want to move up in size. If you venture down to the san jose area, Alliance welding is an awesome little shop with great argon prices and trade in deals.

I would probably choose Mig for a one-use welder, because for most of the things you listed it will be much faster and easier. As previously stated, if you have good hand-eye coordination, and do anything such as computer/video games, cooking, or similar, TIG shouldn't be THAT much harder to pick up, though yes it has a bigger learning curve. Also, if you plan to weld aluminum or stainless a lot, you should get a TIG. If you change your mind about classes, check out the crucible, I think its in Oakland and offers classes.

I don't know how soon you are planning on purchasing a machine, but I'll be working on my next manifold in the summer if you want to come check out/use either of my machines (Hobart Handler 175 MIG and Lincoln Squarewave 175 TIG), or if you want any pointers on either process. Though if you get a welder now and use it a bunch, you may be very good by then.

As far as machines go: Hobart, Lincoln, Miller(cream of the crop) all make great MIG machines as far as I know, and for TIG Thermal Dynamics makes a 185 inverter that is sweet, and ESAB has great reviews. I'd try to stick to those 5 brands, and check craigslist for used.

Evan
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