Which welder do I need?

[Bob Thompson]

With all this aluminum, I figure there must be a number of people on this forum who weld aluminum and can help me get started. I need to weld some 1/8" wall 2" square aluminum tubing to some 1/4" aluminum plate for some sports related equipment I'm inventing. I well need to weld about 6 hours every 5 days or so, but the question is which system, TIG or MIG or torch, and what are the advantages. For now, I'm thinking a Millermatic 140 or 175 MIG system with Argon shielding, or a Lincoln or Hobart equivalent, but my concern is the MIG splatter and cleanup. Is it going to be a problem? Is TIG or torch better? Thanks in advance for advice.

[wahoonc]

Originally Posted by Bob Thompson

With all this aluminum, I figure there must be a number of people on this forum who weld aluminum and can help me get started. I need to weld some 1/8" wall 2" square aluminum tubing to some 1/4" aluminum plate for some sports related equipment I'm inventing. I well need to weld about 6 hours every 5 days or so, but the question is which system, TIG or MIG or torch, and what are the advantages. For now, I'm thinking a Millermatic 140 or 175 MIG system with Argon shielding, or a Lincoln or Hobart equivalent, but my concern is the MIG splatter and cleanup. Is it going to be a problem? Is TIG or torch better? Thanks in advance for advice.

Bob,
I am not a welder or even a welding expert BUT we do have a light production rig at work that I can stick two pieces of metal together with (we actually have someone to do the real welding work) We use a Square wave TIG the unit we have is a Lincoln, I don't think they make it anymore but the current Precision 275 is very similar. Our guy welds from 1/2" all the way down to .040 aluminum with it. FWIW we have both Miller and Lincoln and both are good lines. We did have a Hobart unit, but had problems getting parts for it.

Aaron

[yukionna]

Originally Posted by Bob Thompson

With all this aluminum, I figure there must be a number of people on this forum who weld aluminum and can help me get started. I need to weld some 1/8" wall 2" square aluminum tubing to some 1/4" aluminum plate for some sports related equipment I'm inventing. I well need to weld about 6 hours every 5 days or so, but the question is which system, TIG or MIG or torch, and what are the advantages. For now, I'm thinking a Millermatic 140 or 175 MIG system with Argon shielding, or a Lincoln or Hobart equivalent, but my concern is the MIG splatter and cleanup. Is it going to be a problem? Is TIG or torch better? Thanks in advance for advice.

I offer up a caution note. You may want to consider a welding 101 class as there is more to welding (i.e., safety and precautions) than just choosing the right welding equipment. A friend of mine is self taught in welding and didn't understand what the shielding gas was for. So, when he ran out of it, he stopped using it! He almost passed out from lack of oxygen!

[thecatsandi]

Bob,
1 amp per 1/1000 inch thickness. 1/4 inch 250/1000 would require a 250 amp welder for steel a little less for aluminum. MIG is faster but messier. TIG is slower but cleaner. Welding 6 hours you will need to look closely at the duty cycle of the unit.
Miller or Lincoln is a toss up which one has the features you want. I have a Lincoln SP175 welder and a Miller Plasma cutter.
If you have never welded aluminum before lots of practice is required. It is very easy to over heat it.

[Bob Thompson]

I may have to start thinking about a TIG unit. I'm a fanatic about workmanship and want my products to look great to buyers. The plan is to weld the components, do a wire brush clean-up, clean them with alumiprep, treat them with Alodine 1001 (clear conversion), then paint them with clear Imron.

[JimGolden]

Bob,

I'm going to be doing some aluminum welding myself eventually, on top of 4130 thin wall tubing and a new trailer frame (which will be much heavier).

For what you want to do, you need to get a TIG machine. To weld 1/8" to 1/4" wall material, you'll be fine with a 225amp machine.

I just bought a Lincoln Precision TIG 225. I've only done a little TIG with it so far (my class didn't do TIG, only discussed it) but I really like it. It's also got a stick mode and you can stick weld however thick you want to go.

The cost to go from the Precision TIG 225 to the 275 was substantial. I couldn't afford the 275. But after I talked with the tech folks at Lincoln, I was fortunate in that I didn't need the extra 50 amps for TIG.

If you're going to start welding near 300amp continuous with TIG, you'll need a water cooled torch. You're getting up into the $5000 range now for the machines. I worked on my dealer and he gave me a price that was just about the "show price" and I paid about $2100 for mine.

Anyway, you could oxyfuel weld it. That's how they did airplanes for years. And the rig is much cheaper. But TIG was developed for aerospace and is the replacement for oxyfuel in these applications. I'm finding that it's a real art no matter which way you go. Though, for what it's worth, I did learn oxyfuel in class and I think that is easier than TIG. But TIG is a surgically clean process that gives beautiful welds. Just need practice

Take care,

[thecatsandi]

TIG does give very good results. you will need 220V 50A outlet to plug it into.
If you have not welded before take a class. basic welding skills are easy to learn but take a while to master. I may never master them.
One thing about aluminum. You fit has to be perfect. any gaps will be come wider. Steel can be filled to some degree.

[tn2]

I'm not a welder....but when I took my aluminum water heater tank to a professional to be welded he said "Of course....we would have to TIG it" like in ...there is no other way that would make sense.

[summerkid]

I agree about the welding class & with everything that JimG said.
The best thing about class is that it's fun. The 5 hours just fly by. Plus you get to try out everything for the cost of tuition. We've "learned" oxyacetylene & shielded-metal arc in my basic welding class at the local CC. But we've also experimented with welding, or melting actually, aluminum & taken a swipe at the plasma cutter.

The teacher says the best all-around welder for on-the-farm stuff is a MIG setup.

You can definitely tell when the TIG class has been through the lab because all these perfect-looking pieces of welded metal are lying around; meanwhile, we're turning in welds that look like rusted spitwads of bubblegum. At this CC you can do TIG without any prerequisites.

Our welding text is 900 pages and it's all pretty cool stuff to know.

[Sundance]

Steel is a cake walk compared to aluminum. Get to a class!!
And practice a bunch. Aluminum has no forgiveness when it
goes from solid to pooling. It can get ugly in a hurry.

And yes.......... TIG, spool gun.