hey, i was wondering if some of you guys could help me out here. i would like to purchase another welder but i can not decide whether i would like get a better mig than what i have (a 135 amp mig/110 volt) or if i should get a tig welder. i have also heard of the pulse mig process, which seems interesting to me. not sure how to apply it to welders that do not come with it though. obviously if i had enough money, i would purchase both

what i would like to do with the welder is weld roll cages, fab rear ends, and do trailer repair. making suspension components would be good as well. i can do this stuff now with my welder but there are times more amps would be very useful, along with a little more control at higher amps. i was hoping you folks would be able to guide me as to which might be better. i am pretty good at mig, but have never done tig, although i have no problem and would rather enjoy learning.

 

If you dont mind learining to TIG that is the way to go. Doing roll cages and suspension components TIG is the only option in my opinion. MIG welding keeps you tied to Mild steel unless you spring for the one of the higher end units and that will allow you to add a push pull gun to go aluminum. You can MIG stainless as long as you get the right gas and wire. I have a Miller Econotig for sale. Its the first TIG I bought for myself. It is a weel rounded unit that I have used to do a multitude of things with. We used them at one of the plants I worked at everyday to fabrication jobs.

 

You need to look @ what you're going to be doing and how much of it . The easiest way to differentiate the two processes is that TIG is precise and can do virtually any metal where as MIG is more suited towards production . Mig can do a lot of metals and thats where a good MIG machine will cost as much or more than a TIG w/cooler . You say you need more amps , how much ? I lean towards TIG as it can do most anything but buying one to do trailers isn't a bright idea . TIG would be required if you are welding cages out of 4130 tube . Either way you go buy a good machine , not many regret buying a better more powerful machine but plenty of people cheap out and wish for more .

 

by powerful i mean a 220 volt, 200 amps or just over it. enough so that i would not have to worry about 1/4" if the need were to arise.

sounds like tig is the way to go.

 

Yeah but only if the builds circuitry can handle the added amprage of the new welder. Otherwise you have a fancy welder that blows circuits.

 

builds circuitry? would you care to explain a little more? i am not quite following

 

I think he meant "the buildings' circuitry"

 

oh, ok, that makes more sense. i have a 220 volt right now in the garage with a 40 amp that used to be for a clothes dryer (i use gas now), but i am going to add a sub panel to my home very shortly so i can have 2 50amp 220's and 2 30amp 120's

 

All depends on what you want to spend. I have been very happy with my Miller 250, but also have an Econtig. About 98% of the time, I use the Mig. Most of the things I build are steel or stainless steel, which are perfect for the bigger Miller mig. I have nothing against Tig, I use it when it is required, but mig is my first choice (would not mind having a syncrowave 200 though).

Another thing to consider getting is a plasma cutting torch. You can cut anything that will conduct electricity.

 

Have you priced the tig units vrs mig. a 200 amp mig will do everything you mentioned, use .030 wire help controll the puddle and you can lay down some nice roll cage welds. If you want a tig to weld aluminum and thicker steel it going to cost double if not triple the mig. also consumable are more costly, gas, tugnsten, collets, collet bodies and cups are all differnt for the differnt thickness materials. If you are just learning you will deffently dip the tugnsten about 100 times before you can get past that this all cost alot. In the end the tig cost alot more to buy and more to operate. the tig is also alot slower than the mig.
I have both units and I will tell you the only time I use the tig is for aluminum and thin stainless. I have built four links to A-Arms and the mig is my choice. some times I will drop down to .025 wire for more controll. Also you can and I do put stainless wire in the mig for any stainless that needs to keep its ss properties. you can also weld stainless with regular wire with absolutely no problems other than the weld will still rust. I will say I use my mig 98% of the time also.

 

Well, that’s a loaded question…

There will always be the people that will tell you that you’re not doing it right or not doing it the best way if you’re not TIGing it. The other side of that is that there are places where each shine, places where either will work and places that you’re wasting your time…

MOST if not all of what you asked about is a more power question, and that being the case I would be looking hard at a bigger MIG. TIG really only shines when the question is accuracy or welding some odd metals. The ONLY thing that you listed that might require a TIG is if you were doing roll cages for some sub 8.5second cars which require chromemoly (or maybe the NHRA/IHRA will come to their senses, learn something about safety and outlaw it like in other motorsports). The fact is that most serious shops that do a lot of roll cages are either tig welding chromemoly cages or the rest are using MIGs (and usually small migs). A great example is one of the more serious fab shops around here which has 3 tigs up to a 500A Miller and probably half a dozen different MIGs do all of their roll cages that I’ve ever seen them do with an old miller 130…

Of course, if you _really_ wanted to go TIG and insisted on using it for the heavy work that you’re listing I suppose that you can always use the TIG as a stick welder, of course, if you wanted to that you could spend a fraction as much and buy yourself a tombstone or something similar and go and stick weld.

The other side of this is, do you really need a bigger mig? Anything over 1/8” thick you should be beveling/leaving an airgap to get proper penetration. Past that, a bigger mig just means fewer passes or less of a weave needed to fill the same weld, in other words, that you can get that weld done faster if you want.

 

i really want something that is 220 volt for more power, and a better duty cycle. my welder has a 10% duty cycle, so i will sometimes spend a bit of time hanging around. i do not foresee using chromoly in the future, but i do want to play with aluminum. i was not aware that you were able to purchase SS wire, but i will certainly do so now that i know. i do see my self doing a mild steel roll cage in my car, and fabbing up a rear end or two. i believe these are out of the question of my weldmark 135+.
it seems that for a garage fabricator, like my self, mig might be the way to go. i guess the next question i have is how big do i need? lincoln makes their 175hd, but i don't whether its worth that kind of money just to gain 40 amps. i think i might be better off getting a bigger machine. i can get a pretty good deal on a miller 212 right now (1350), but the cost to go aluminum with miller's machines makes me want to go tig instead (1850 with aluminum set up). 500 for aluminum upgrade with the miller machine is certainly a decent amount. i like the way the lincoln's aluminum gun and such adds to around a hundred dollars, but i do not know much about their migs in that class, nor do i know where to find them.

 

I'm not up to speed on this topic, is chromemoly inferior? I had always been told it was the lightest and strongest. Is fatigue the problem?

 

I have a 140A Murex MIG. Have done for almost 14 years now, and it is one of the best purchases I ever made.

It has been able to weld anything Ive tried.

And 2 important aspects aboit TIG vs MIG... lets see you tack stuff together with a TIG !!!! its nearly impossible for one person, and a MIG is also much easier on gas.

Id buy the MIG...if you somehow find it isnt doing everything you really need...then you could consider TIG options. But I know I wouldnt be without my MIG ( I also bought a TIG this year, and my TIG welding is really crap )

 

go for the 212 mig, but be warned: spool guns suck.
If you want to weld aluminum that looks worth a darn go spend alot of money and buy a nice tig unit. When you get home with your 4000 dollar purchase spend another 500 to get the power needed to run the unit in your garage. Oh yeah plan on an addition to the garage cause with the big ol tig you'll need more space in the garage.

 

I would go with a lincoln tig machine. However theres alot you can do with a mig too. Id spend the cash on a tig and a small compact mig perferable a lincoln 175 220 volts.

 

May I suggest that if you're stepping up the service anyways, put in 60 amp 220's...It's been well worth it for us in our garage.

I personally love TIG welding...anything involving my safety (roll cages, suspension stuff)...I'd rather know it's TIG welded properly.

 

Heh, I’d rather know that it’s welded properly period. When we’re talking about mild steel thicker then about 16ga, I usually feel much more comfortable seeing a properly done MIG weld than TIG, unless I know the person doing the TIGing. Because of how easily you can control heat and filler feed with TIG, it’s much easier to run a pretty looking superficial TIG weld. You can make a crappy weld with most welding processes… but TIG seems to be especially adept at making nice looking, crappy welds.

Romo… to be honest, you’re the first person that I’ve really run across actually hitting the duty cycle limits of your machine. I regularly use a few different 135 series welders, and have never run into that issue, even with some big, heavy welds/weaves… Have you by any chance used any of the big name welders in the same range and compared, I have to wonder if it’s just an issue with that welder (forgive me, I’m not familiar with a weldmark 135+). I have my preferences and dislikes with the small machines but once you get around them most of them can do a quite decent job for most “home” type welding.

If it’s not a machine problem and really an issue with the limits of a 135 series machine, than going with a 175/180 series machine probably won’t fix it. I regularly use my HH135 and a friend’s HH175, and I can tell you that besides the outlet you plug it into there really is not that big a difference, and the difference isn’t where you’d expect it. The place where you see the biggest difference between the machines is that the HH175 has a lower, low power setting making it just slightly easier to use for stuff like 22ga body sheet metal.

My $.02 based on your reply, I would decide based on your aluminum needs, since that’s where you’ll be limited. If you intend to do aluminum much thinner than about 1/8” then a spool gun on a bigger mig just won’t cut it. OTOH, if you can live with being limited to aluminum >3/16” then I’d go with the big mig (I personally would love a MM251 or something similar in my shop, having the ability to play with spray arc… would be kind of cool and just a bigger power supply for welding that heavy plate in a single pass or with less prep work would be nice (but again, not necessary). OTOH, if you intend to do some fine/precision welding, welding thinner aluminum, or care about the “it’s not welded right unless it’s TIGed” weenies, look at a TIG and consider replacing your MIG with a better small mig unit (the TIG will give you extra capability, but when it comes down to it in most small/home shops you’ll use the MIG more, it’s cheaper, uses 1/3-1/5 the shielding gas, it’s about the same amount faster, more convenient…).

FWIW, I have both. I use the MIG probably 90% of the time and would miss the MIG more than the TIG if I didn’t have it.

 

Mild steel (1018, 1020, 1026…) and 4130n (the grade used in a chrome molly roll cage) weigh _exactly_ the same and have almost the same strength (usually the 4130n will be given an average tensile or yield strength 1-2% stronger than the mild steel, your welds and the structure design will have a much greater impact on the total strength, assuming that you use the same thickness tube…).

The difference between the 2 is that 4130 can be hardened. That’s great when the finished piece can be put in a heat treat oven for a few days and properly heat treated. But otherwise, what happens is as you run a weld bead, the steel around the weld is still enough cooler that it quenches the 4130 right around the weld, resulting in a very hard and very brittle spot around the weld (the actual weld stays soft since mild steel filler is used for welding together 4130 roll cages, which again, does not heat treat), which on impact would shatter forming a sharp, pointy spear rather than deform and absorb the energy that the mild steel tube would.

There’s a lot of serious metal and chassis fabricators that will not put 4130 in a safety structure anywhere near a driver, and some racing sanctioning bodies like NASCAR have totally outlawed it’s use.

 

I agree with you that someone who doesn't actually know how to TIG weld can certainly make a very pretty weld that sucks...I prefer to TIG on my own cars because I have been TIG welding for a good amount of time with a good amount of instruction now. 99% of the welds I do for my own car are welds that are going to be seen all the time...stainless exhaust work, aluminum intake work...I feel that sort of stuff should be TIG welded for the right "look" for my car (my Impala, not my Camaro).

I also agree that there are a lot of meatheads who say "it isn't right if it isn't TIG'd" as there are a LOT of welds that should be done with the MIG. I'm planning to MIG my subframe connectors on my Camaro. Partly because when done right it will be more than strong enough, partly because I just don't feel like spending that much time on my back with the tig torch...especially when I don't think I can weld them well with the TIG at all.

Any of you guys ever TIG'd titanium?