Looking for a TIG welder for aluminum

Oak · #1 12-08-2021, 02:40 PM

Hey all, I have a question about welding cast aluminum. I recently picked up a 2072 with a broken tab on the front of the transmission. I know the front tabs are not needed with the brace kit that I will install on this machine but I would like to try and weld it back on. I have an Esab 252i mig, tig & stick machine that I thought had the capability of welding aluminum but it can only weld DC tig. So, I will need an AC tig machine but don’t want to drop $2k on one. I found the attached machine with a 6 year warranty and was wondering if anybody could give me some direction on what machine to purchase.

https://www.eastwood.com/eastwood-ti...dc-welder.html

R Bedell · #2 12-08-2021, 03:28 PM

IF.........you are not going to do a lot of Aluminum Welding, wouldn't paying a Professional Welding Shop ($50-$100) for this repair, cheaper than spending $850.00 ??

Oak · #3 12-08-2021, 06:41 PM

Yes, I could do that and probably should but it's something I'd like to learn how to do.

spndncash · #4 12-08-2021, 08:33 PM

have you tried to use the MIG with a spool gun and a reverse polarity setting? The thick casting will likely be easier to weld with MIG than with TIG.
And, you'll need argon or argon/helium if you dont have it. you cannot weld aluminum with co2 in the gas mixture

Oak · #5 12-08-2021, 08:49 PM

Well, that was my first thought also with the gun but when I looked up the number for my machine the gun was $700+. I didn't look to see if I could find a gun cheaper yet. I do have a tank of argon.

IIRC I was thinking that I heard people say the guns didn't work that well on aluminum. I don't know if that is true.

spndncash · #6 12-08-2021, 09:27 PM

You would have to be real good with a gun to MIG weld THIN aluminum. I would say TIG is the only way to go on thin sheet aluminum. On medium thickness say 14/16 gage its not difficult either way. Thick castings, I have not used a TIG since welding school many many years ago. I am too old to Tig anything that is not on a bench. if you want to TIG the eastwood is not bad, priced alright too. I live real close to the eastwood store in Parma. they are fun to go to and have classes regularly. I have Lincoln or Miller for mig/tig/plasma because years ago those were the only options and my forty year old equipment is still supported for consumables.
Getting it clean is most important. clean it/grind it then clean it out again! you likely should heat it up to get any oil/grease out then clean it with acetone and heat it again -get some heat into it and contaminants out. they will ruin the weld no matter what you use.

spndncash · #7 12-08-2021, 09:37 PM

I may have been reading into your post. I was assuming you are welding the tab on while still on the tractor.
If the transmission is on the bench then I would TIG it. Torch in one hand, filler in the other foot on the pedal. I cannot do that while lying on my back anymore - on the bench no problem
If you are welding the tab to the transmission while still on the tractor I would MIG just because one hand does all the welding and the other can hold the broken piece in place scratch your butt whatever! haha

Oak · #8 12-08-2021, 11:06 PM

Good info spndcash! Yes, I have the rear pulled out of the machine and on the bench for other repairs needed. I'm too old to lay on my back and try to weld something anymore.

Thanks.

Hairtrigger · #9 12-09-2021, 07:23 AM

I never caught on to TIG welding. Stick and MIG are no problem for me
35 years ago I made 2 aluminum snowmobile trailers then bought a Miller Welder with a spoolgun so I could do more aluminum fabrication.
Then I never did, I have run a half of a small spool of stainless thru the gun but basically bought something I never use ?
TIG is definitely the way to weld thin aluminum

Ambush · #10 12-09-2021, 11:47 AM

Tig is far superior in the case you present. I've laid a lot of aluminum rod into oil soaked Cat torque converters. Use some heat to sweat out as much oil as possible. V the joint equally from both sides. There's a good chance you'll have to lay some weld on the material then remove it with an aluminum burr. Each time you do this you'll seal off contaminates. Then tig in from both sides.

You need straight argon for aluminum.

You can do the same with a spool gun, just not as controlled and not the same weld integrity.

To make it much easier, just fill the bolt hole in to if it's too close to the weld, then re-drill. Also leave the bottom side a bit proud and file to plane. Then you don't have to worry about keeping it all perfectly flat and you'll have no induced tension on the tab

I think the newer Miller 215 combo does DC/AC tig and has auto polarity switching. Not sure. I just helped a friend set one up for mig but he didn't have a tig torch. Very nice home unit with 220/110 options. 220 is far superior to 110, but 110 is definitely better than nothing.