TIG welding

[300kGN]

I've been using a MIG w/spool gun for welding aluminum down to .063" but its tough, and generally looks sloppy. I want a TIG but I'm not sure I can learn to use 1 on my own, they are expensive, and then there's these...
Nice TIG Welder

Miller Synchrowave 180SD

someone told me any Arc welder can be converted to a TIG. How true is that and how usable is a converted arc welder when it comes to TIG'ing sheet aluminum? I think I would rather get a true TIG but damn, if I can do the same thing for less than $500, WTH?

 

[notacarlo]

150 is nice. I use a 200. You can learn to use one on your own. Just lots of scrap, tungsten, and gas. The Miller site has a great step by step technical manual on TIG.

Pure tungsten for aluminum
2% thoriated for mild steel

I practiced blending metals before I started to add filler. When blending, you can clearly see how much material needed to be added to make a sturdy weld.

 

[turbofabricator]

My best advice is to buy an oxy-acetylene torch and master gas welding FIRST!! If you can gas weld and make your welds look and perform great, TIG welding will be MUCH easier. TIG welding is just like gas welding with the advantage that you can control the heat with out moving the torch away fom your weld puddle. I have a Lincoln 175 square wave and a Miller 250 TIG. (and a Miller 185 MIG, Thermaldyne killer Plasma cutter, and a Oxy acetylene set-up. And a tool box full of cresent wrenches to do everythng I do.) The Lincoln 175 will wled 80% of what I currently do, but bought the Miller 250 for Intake manifold work. The 175 has been able to weld these projects: (note: on the thicker aluminum, I had to pre-heat the aluminum first with the oxy-acetylene torch) You will also go through alot of consumables at first, so have an acount set-up at your local weld shop. And learn the names of all the little do-hickies inside your torch that hold the tungsten and stuff. You'll want to be able to tell the guy what you need, because you melted it. I am a self taught TIG welder, too. I did spend alot of time looking over the shoulder of some really good welders, though. One welding buddy of mine use to say, "I can weld ANYTHING...................I can weld WOOD!!!":biggrin: (And seeing the way he welds, I never asked him to prove it, 'cause he probably could, weld wood!) ( my attempt at poetry)

 

[300kGN]

So, what's the deal with the coverted arc welders?

 

[tttype]

you can now buy cheap dc tig inverter welders for a couple hundred bucks, but they cant weld alum. need square wave ac for that.

 

[300kGN]

Now thats what I was after!

you can now buy cheap dc tig inverter welders for a couple hundred bucks, but they cant weld alum. need square wave ac for that.

I assume you know that for a fact. I figured there had to be some limitations when using a converted machine.
BTW, Ken- I like the oxy analogy, you mean I can use the torch for more than blazing destruction:biggrin: ?

 

[RmvBfrFlght]

I have a stick welder that I also use for TIG. The base unit is a 230 amp AC only box. Adjustable from 40 (or so) through 230 amps. Built a rectifier box with four big diodes, heat sinks, and a couple of cooling fans. Also has an inductor in to help smooth the current.

This provides an AC/DC set up for stick welding. I still use stick for the stuff that doesn't really need to be TIG'd. It's cheaper.

For TIG, got a bottle with argon, torch setup (air cooled), and a flow regulator. I hook it up to the DC box for steel and such. This works decent and have built a lot of 'stuff' with it.

Although there are areas that are lacking. Need to scratch start, so use a piece of copper clamped to the area to be welded. Shouldn't scratch start on the work piece.

It is also lacking a variable amperage control. Such as a foot pedal or thumbwheel. So need to use other methods of controlling the temperature.

There isn't a turn-off either. So at the end of a weld need to break the arc and get the cup back over the hot weld. And of course not restart the arc while doing this. Need to continue to shield the weld to prevent it from oxidizing.

Without a high-freq box can't really do aluminum well. I've played around doing aluminum with DC, but it isn't easy. It is usually done with AC to agitate the pool and break up the oxide coating. The high-freq re-lights the arc as it goes out at each crossing.

Now for a really slick DC set up, driving an alternator with a motor is a treat. Can easily adjust the field current to control the output current. And the DC being from a 3-phase system is pure (RMS) DC.

RemoveBeforeFlight

 

[turbodave231]

My advice is go to your local community college or trade school and see if they have a welding program. See if they have a TIG class.

I did this several years ago and I learned so much I can't even begin to explain. I had a variety of high end machines to use and lots of material. The money and time spent was a great investment.

Previous to taking the class, I bought a Lincoln TIG 175. I though this would be enough to fab with aluminum. Yes it will weld aluminum........, but not as nicely as I want. If you want a real welder that will lay the "row of dimes" in aluminum, go buy a Miller Dynasty 300-350. The Dynasty is a high frequency inverter machine that BLOWS away any other TIG welder for aluminum I've used.

In defense of the Lincoln and smaller TIG machines, they do a great job welding steels. You can do great work in steel with a small machine. Welding in steel takes much less current because the heat stays localized. Welding Aluminum takes TONS of heat because the metal dissipates the heat up so quickly. That translates into high frequency and tons of current to generate the heat needed to maintain a weld pool.

A small machine just won't do it........and yes you can pre-heat parts, but what a PITA!!! My wife gets really mad when she finds "car parts" in her oven!!!!

 

[turbofabricator]

I agree Dave. I just stepped up to a Miller 250 HF (old HUGE machine on craigslist). It welds aluminum much better. Had my son out in the shop learning how to weld with a TIG. I started him on Aluminum. Told him that if he can weld aluminum, he can weld anything. Even Titainium welds real nice. I gave it a try a few years ago, and thought it would be real tough to get a nice bead. NOT the case. It welds real nice. Just have to back purge if you can see the back side. If it is hidden, it looks like GOLD were you run the bead. Back purging would do the same on the back side, though. Not much need for Ti, though.

 

[turbodave231]

Ken,

I've found Stainless steel the most challenging. The backpurge is essential and you definitely need to limit the heat. The stainless weld pool is gooey and not viscous like regular steel.

Running aluminum is easy and fun!!!! but again, you need the right welder!

Dave

 

[ijames]

If your isp offers usenet news, go to sci.engr.joining.welding. If not, go to groups.google.com and enter sci.engr.joining.welding in the search box, and start reading. This is basically the equivalent of a forum like here on turbobuick.com, but for for welders. Some real pros (take anything Ernie Leimkuhler says as gospel, he's been teaching this stuff for 30 years ) and some beginners; most willing to help and answer specific questions. Some of the posters there block messages from google so that's not the best way to post but you can read everything and search for back articles and recommendations.

 

[300kGN]

I'm set up to do substitute teaching at the local Vo-tech and had been planning to mooch in on some of the welding instructor's knowledge. Just have not had the chance yet. I have also perused some welding forums and Miller's tutorials-pretty much a learner by doing/watching type so Im really looking forward to getting in a class.
I figured that was the case with the converted boxes versus big$ rigs, and my researched concluded the same for Miller vs Lincoln. Its like comparing Snap-On to anything else, sure it'll work but just not as well.
Dave, I like your descriptions! Goooey! I thought I was doing something wrong w/my MIG and stainless had the same experience, like welding with frozen caramel I too enjoy aluminum (w/MIG), blazing fast but not always in control at my skill level. With the small amount of reading I've done re. TIG, I've been intimidated by the seeming infinite adjustments, consumable selection, etc. Which is another reason to seek out proper instruction.

Thanks for all the input, if I can do 1/2 as well as the master turbofabricator I'll be happy:biggrin:

 

[TurboTerry87gn]

I say go ahead and buy the tig welder. I have a syncro wave 200 by miller and love it. I learned to weld on my own, just read and practice. A note of caution!!!!!!!!!!!!!!! 2% thoriated tungesten is radioactive when grinding a new point on it so wear a mask!!!!
But if you have the money to buy an inverter tig you can use the newer tungsten blends that are not radioactive.

The welder will eventually pay for it's self with all the projects you use it for trust me. don't buy a no name. Save your money and buy a syncro wave or a good lincoln.

 

[300kGN]

synchrowave 500

I found a synchrowave 500 on Craigslist for $1500. It sounds like a hell of a deal but a lot of overkill, not to mention its massive.

 

[turbofabricator]

I found a synchrowave 500 on Craigslist for $1500. It sounds like a hell of a deal but a lot of overkill, not to mention its massive.

That machine would REQUIRE a 480V 3-phase to even turn it on. NOT a home garage unit. (220 single phase is all that 99.9% of homes have access to.) It would be capable of welding the hoover dam to the rocks surrounding it, though.

 

[aminga]

That machine would REQUIRE a 480V 3-phase to even turn it on. NOT a home garage unit. (220 single phase is all that 99.9% of homes have access to.) It would be capable of welding the hoover dam to the rocks surrounding it, though.

My brother in law had a deal on some piece of farm equipment once but it was 480V 3 phase. The power company wanted $15K to do a three phase drop to his equipment shed. If you don't already have it 3 phase is an expensive proposition.

 

[typhoon]

220 3 phase can be done for $1k or less depending on amps. Probably not for a welder though.

The 180SD is a good machine, had one. Upgraded later to a 250 but the 180 did a lot of work for me.

 

[300kGN]

sync 500

The seller says its single phase- that was the 1st question I asked. Just too much over kill.

 

[Louie L.]

Duplicate see below

 

[Louie L.]

I built my entire turbo kit using a Thermal Arc 185. Tigged aluminum,mild steel and stainless. The unit is compact and not huge and bulky like the big blue box.

Ive done frame work and suspension work with it. I certainly got my 1600 bux back out of it.