We had some of the first ones to come out and found that the feed wheels were not gripping the wire right. Seemed like maybe the wheels were marked wrong for the wire size. Also the controls just seem so touchy, really hard to weld thin material. And when spot welding you have to turn the heat range to max to get any penetraion. They just don't start out hot enough IMO. I haven't heard of any corrections to these problems and the last I saw one of the reps. was about a week ago. Our supplier has hoarded as many of the 135s and 175s he can find, so that should say something.

Legion- I've not used the 155 because they are only for tig'ing steel (dc). We do have a few of the 205s and I've been impressed with them. Their only downfall is the short duty cycle with thicker alum. but on thin alum. I've welded all day with no trouble. Big price difference though. I would look into the miller econotig or the hobart tigmate. They seem to be a little cheaper and have heard good things on both.

I'd really like something that does Mig and Tig, AC and DC, but they are pretty pricey. We're looking at $3,000 - $5,000 for a full rig.

Although, when I sell the 951 it will free up quite a bit of cash...

Tim, what kind of gas(ses) do you run for Tig? Do you do any Mig? If so what gas(ses) do you use for that?

We were running 75% AR and 25% CO2 for Mig and 100% AR for Tig in my welding class...

absolutely love my Miller 140autoset. it is one smooth ass machine! i do wish i could do al. and ss but my usage (beyond working on the car) is for fun only.

i found Tig to require a LOT of coordination (amazing stuff though) and if i do hit the lottery one day i will most certainly own a nice tig machine. however i am totally happy with my Miller mig.

there is something so totally satisfying about laying down a weld that sounds absolutely nothing like bacon frying (i think this analogy was coined by a lousy welder).

Chris, the place I work at uses Ultramix (75%-25%) for it's wire welders that are strictly used for steel, but at home, I have a big tank of argon for my tig welder and a small tank for my rarely used 110 wire welder. In recent years, I had my small tank also filled with argon as it works fine also for steel, but I wanted a back up if I ever ran out of gas in my tig welder on a weekend.

Also, when I mentioned the AC/DC thing in respect to inverter tigs, I am talking about the output "welding mode" which is "Electrode negative" (DC) for welding steel and stainless. For aluminum, you set the welding output to AC. The inverter types IIRC, are DC output only (I guess that is why they are called inverters as they convert the 220 AC house current to DC only). They work awesome for welding steel and stainless steel, but they do not have the high frequency AC output available like larger old school tig machines. I am guessing that other companies like Hobart, Lincoln etc offer full feature relatively inexpensive air cooled torch models similar to the Miller Econotig like I have. I would not be afraid to buy any of those name brands, I just happened upon a good deal on my barely used Miller Econotig a few years back. My Econotig does have a set of stick welding cables that plug into it, so for welding heavier "farm" type stuff, I on occasion will use that feature.

Thousands of roll cages have probably been built with mig welders, but for critical stuff made of relatively small diameter thin walled tubing, tig is BEST as once you master it, you can accurately control the heat from start up of weld on a cold metal to the end of the weld when the metal is hot. Mig starts cold until the metal heats up. You often end up with either not enough penetration at the start of the weld, or you burn thru too much at the end of the weld as the thin metal quickly becomes hot. I wouldn't worry too much with the average roll bar, but I won't pull 6 g's in an airplane if I don't think it has 100% penetration in all of the tubing cluster joints.

our invertec v-205 is a ac/dc machine Wonder if that was a fluke Tim! :D

Anyhow I would shy away from Miller right now noty much good going on there with TIG machines at the moment. Lots of bad PC boards. The ESAB and lincoln Tigs are better at the moment. I have at home a ESAB Heliarc 161 Tig Machine. it works wonderful. But I also get the choice of a dynasty (miller) 300 dx,synchrowave 350 (miller), and many others at school. I used to be a big miller Fan but just have terrible luck at school with the millers

Ben, I have not looked into these small tig welders recently, but a couple years back, the small relatively inexpensive ones were indeed DC only. The 205 you mentioned sounds like a nice unit. I checked Lincoln's web site and the 155 Legion mentioned is indeed DC only.

As I noted before, at the time I got my then 1yr old Miller Econotig, I got a good deal on it (traded an old basically junk experimental airplane project for it which I valued at about $1000).

For the real thin stuff, I would rather have one of the small inexpensive DC only machines, but I occasionally need to weld aluminum, so the Econotig is just fine for my home shop. I have added a thumbwheel torch control (a must have for welding in large awkward airplane fuselages) and I bet I use my welder once a week on average even when I am not in the middle of a big project.

Whew! That invertec v205 is pretty pricey.

Tim does the econotig have any limitations in the metal it can weld?

Just saw an ad on the miller site for a spool gun that fits the 140 and 180. It would surely be fun to try it.

There is an aluminum spool gun kit for the Lincoln 140 & 180 too. I was a bit sceptical, having read here about MIG welder's limited ability to do aluminum. However, the guy at the welding shop showed me some pieces they had done with the Lincoln 180c... looked pretty good.

You guys are talking about a spool gun for Tig of Mig?

sorry, for a 110 Mig machine.

None that I am aware of. It has four basic mode settings: AC high & AC low (what I use for aluminum), DC Electrode negative (what I use for steel and stainless steel), DC Electrode positive (what I use to create a ball on the end of a tungsten to use on aluminum)

MB911 could probably advise on welding exotic metals that I have not encountered.

Thanks Tim. How about working with relatively thin al like on a radiator or catch can?

The thinnest aluminum I have personally welded with my Econotig, was .050" 5051 aluminum sheet that I made butt welded aircraft fuel tanks with. I am confident it would weld thinner aluminum, but I could not say just how thin. I did a good job on my tanks, but I am much more experienced with tig welding relatively thin steel components. Most aircraft aluminum is 2024 and therefore is usually riveted together, while most steel parts are 4130 and welded.

Butt welding sheet aluminum tanks is difficult in that one must keep the gap to a minimum which means many tack welds. Tack welds are kind of dirty and when doing the final welds, it is difficult to maintain an even "stacked dime" type appearance as you keep running into the relatively dirty tack welds. Cleanliness is critical for aluminum and I always go over the joints with a clean stainless "aluminum only" brush in between tacking/finish welding.

No such thing as a spool gun for tig unless it is Hot wire tig which is used in orbitals.

seriuosly look at ESAB units. Very nice quality.. The econtig's use to be great but have steadily lost ground.. I do like the older ones

I think he is refering to thickness and yes the econtig does have limitations 1/4 inch aluminum would be max IMHO and probably require a good preheat. But you probably won't be doing that any time soon

I've seen Tig torches for manual use that have a wire fed in next to the electrode. Not sure if you would consider that a spool gun, but they do exist. Not very common as you cannot change direction with them.

Look at the bottom torch:

http://forums.pelicanparts.com/uploa...1193184311.jpg

I have a Lincoln sp 100 that I bought in 1989 and other than one of the guys at the shop cutting through the cable I have never had a problem with it and I use it constantly and am pretty hard on it. Great machine.

those are not hand helds those are for orbitals and are typically hat wire meaning they are positivly charged.