Feasibility of Aluminum or Chromy MIG?

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Assuming of course pure argon gas and a spool gun. How does MIG welding aluminum stack up to TIG welding it? Same question for Chromalloy tubing given the proper equipment (though I dont know that the right gas and equip is for chromy).Victor Journeyman OA TorchVictor Edge RegulatorsLincoln 180HD (240v) MIG/FCAWShark LT v7 CADMiller Digital Elite Helmet35 Milligrams of Insanity
Reply:The 180 can do the job. You really want a spoolgun for the aluminum. The welds will not be the most beautiful, but yes, you CAN get a good weld with the 180. As for chromo, use your standard er70-s2, s6 wire, and the 80/20 gas, and go to town.All the major brand 180A welders are basic machines, with all the arc form preset in the little brain they run on. Without things like adjustable gas flow, hot start technology, arc control, pulse...you are just limited to a machine that melts metal. Not to say you can't do beautiful welds on steel with them, and with practice, good looking strong welds on aluminum. Just saying, unless you are a WIZARD, they won't look as nice on aluminum as a tig weld.Your steel welds can come out as pieces of art, and the welds can be as strong as the day is long, and then some. It's all about the practice.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Originally Posted by RellsAssuming of course pure argon gas and a spool gun. How does MIG welding aluminum stack up to TIG welding it? .
Reply:I am more asking in general. I have been burning holes in mild steel tubing practicing up to where I feel I can get good solid welds with FCAW on the tubing. I have tons of wild contraptions of welded and cut tubing. Been welding, cutting through welds to see quality and so on. Rinse and repeat. What I am really interested in is skilling up to building some sort of buggy or off-road vehicle frame. Some day maybe even a bit of racing but that is way off in the horizon. Hence the question about chromy. As for this thread, I am just currious in general what the applicability is. Propaganda says MIG can weld anything. I wanted to know what the people here who have far more experience than I think.Victor Journeyman OA TorchVictor Edge RegulatorsLincoln 180HD (240v) MIG/FCAWShark LT v7 CADMiller Digital Elite Helmet35 Milligrams of Insanity
Reply:Mig can't weld EVERYTHING, but a decent mig's got a wide range of uses. A good 220v 200+ amp class machine that will accept a spool gun, will weld thin 18g sheet all the way thru 1/2" steel with gas no problem. You can probably run a bit thinner with good techique, and thicker with good prep and multi pass welds. The spool gun would let you easily do 3/16" - 1/2" alum. Use of FC wire would let you do structural welds outside in the wind where gas would be an issue. A 250amp class machine would run dual shield FC for production.If you are serious about building a buggy, dump the FC wire and get a bottle of 75/25 gas. You will be much happier. Thin tube and FC will be frustrating at best. I also believe FC not really recomended for chrome molly tube in that application. Usually everything I've read has been mig with gas or tig on that. If you are using FC because your machine's not powerfull enough, then you want to think about stepping up to a 220v machine as well as adding gas..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by DSWMig can't weld EVERYTHING, but a decent mig's got a wide range of uses. A good 220v 200+ amp class machine that will accept a spool gun, will weld thin 18g sheet all the way thru 1/2" steel with gas no problem. You can probably run a bit thinner with good techique, and thicker with good prep and multi pass welds. The spool gun would let you easily do 3/16" - 1/2" alum. Use of FC wire would let you do structural welds outside in the wind where gas would be an issue. A 250amp class machine would run dual shield FC for production.If you are serious about building a buggy, dump the FC wire and get a bottle of 75/25 gas. You will be much happier. Thin tube and FC will be frustrating at best. I also believe FC not really recomended for chrome molly tube in that application. Usually everything I've read has been mig with gas or tig on that. If you are using FC because your machine's not powerfull enough, then you want to think about stepping up to a 220v machine as well as adding gas.
Reply:Missed the 180 in the sig..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:A 200 amp welder is really inadequate for 1/2 inch aluminum, you will need closer to 300 amps for MIG, 400 amps for TIG.  The welder manufacturers talk out of both sides of their mouth on some of these issues, as you can see below.How much power do you really need to TIG thick aluminum?Syncrowave 200 (200A max) claims to weld 1/4 inch aluminumSyncrowave 250 (300A max) claims to weld 3/8 inch aluminum.Syncrowave 350 (400A max) claims to weld 1/2 inch aluminumMiller has a table with the following data: 1/16 requires 60-90 amps, 1/8 125-160 amps, 3/16 190 to 240, 1/4 260-340, 3/8 330-400The Lincoln book says 375-450 amps for bevel butt welding 1/2 inch aluminumRemember that preheating reduces current requirements.How much power do you really need to MIG thick aluminum?Millermatic 212 (210A max) claims to weld 3/8 inch aluminumMillermatic 252 (300A max) claims to weld 1/2 inch aluminum in a single pass.Millermatic 350 (400A max) claims to weld 1/2 inch aluminum in a single passMiller's MIG welding calculator says 300 amps for 1/2 inch or thicker aluminum, 220-250 for 3/8"The Lincoln book says 240-320 amps for butt welding 1/2 inch aluminum, 240-280 for flat fillet.Note that Lincoln suggests constant current if you need more than 350 amps on aluminum!MIG is the preferred process for thicker aluminum, with 300 amps offering a lot of capability.  The general rule seemed to be 1/8 and thinner, TIG, thicker than 1/8, MIG.Sculptures in copper and other metalshttp://www.fergusonsculpture.comSyncrowave 200 Millermatic 211Readywelder spoolgunHypertherm 600 plasma cutterThermal Arc GMS300 Victor OA torchHomemade Blacksmith propane forge