MIG on Aluminum

Date 11-30-2003 22:56

The first question you need to ask is what thickness aluminum you will want to use. 1/8" aluminum is about the thinnest you can reasonably do with MIG. You may be able to go a tad thinner to 14 ga with a little practice. It's not very easy to tack aluminum with MIG not to mention that it's usually an ugly glob. The thickest aluminum that I can do with my 220 Millermatic 175 is 3/16". Aluminum takes a lot of power since you need to get into spray mode. Portabillity is kind of a misnomer with MIG welders. Yes, most people have a 110 outlet in their home, but you still have this gas bottle to lug with you. The small 48 CF bottle is portable, but if you do any amount of welding, you'll upgrade to the 113 CF bottle at which point you're hesitant to want to take this thing anywhere. This also all hinges on you being willing to disconnect the regulator and hoses from the bottle and welder, reconnect it at your friends house, then repeat everything after you're done. I've done this a couple times and now require my friends bring their stuff to my house.

Also, since aluminum wire is soft, you usually need to get a spool gun to weld aluminum. With the smaller machines, the additional equipment can be upwards of $600 over the price of the welder. So to weld aluminum your looking at about $600 for the welder and $600 for the spool gun and controller. This is close to the price of an entry level AC/DC TIG machine. Of course, these machines are not very portable at 300 lbs.

If you're looking mainly at welding light gauge steel (i.e. 16 ga and less) and less than 1/8" aluminum, TIG would be a better choice. MIG is easy to learn and is a good choice to welding steels 14 ga and thicker and aluminum 1/8" and thicker. MIG can, and is used a lot, for welding thin gauge sheet metal, but is not the best choice IMHO. It leaves a lot of filler which needs to be ground off for a nice finished product. Although TIG is harder to learn and slower, it excells in these thin materials and in Aluminum. You also only need one gas bottle (argon) for all metals vice 2 or 3 for MIG if you're doing steel, aluminum and stainless.

By Mathius (**)

Date 12-02-2003 09:22

I'm probably going to be welding on a variety of thicknesses, but mostly thicker stuff. I'll be using it for my own personal projects for enjoyment, such as pedal cars, building a bed frame, or whatever other crazy ideas pass my mind. I prefer aluminum because as I said, while it is still comparibly strong, it is also light and while it does oxidize, I don't have to worry about rust.

You make a good point about the spool gun and such upping the cost, which is something I didn't necessarily foresee. As far as lugging the cylinder around, that doesn't concern me as much. I imagine I could weld up a MIG cart pretty quick that will bolt everything down tight.

I know TIG is the preferred for aluminum, but even with the cost of a spool gun, the MIG is almost always considerably cheaper even in 220, and I don't have to have access to a water or air cooling hookup to run a MIG. MIG is faster, and easier to work with. I'm just learning TIG in school and it's taking me quite a bit of time to learn, while I picked up arc, MIG, and even acetylene pretty fast. I wish I'd have spent more time on the acetylene, as it is very closely related to TIG.

I guess basically I'm looking for a money question here. Down the line I'd like to be able to afford a better machine, and even maybe a TIG at some point. Right now, all I have is a little 90 amp flux core welder that only runs .30 and won't even let me hookup a bottle. If I were to buy a cheap 110V true MIG, that advertises it'll run aluminum, am I wasting my money or will it get me by for a while?

Mathius

By kekoakeakane (*)

Date 12-02-2003 09:59

Yes, you would be wasting your money on the 110 machine. This is especially true if you'll be welding mostly on the thicker stuff. The 220 machines are not that much more expensive than the 110 but give you a much broader capability. Gaining access to a 220 circuit shouldn't be that difficult. Unless you're running completely on gas, most homes are wired for a clothes dryer, or oven which is good for running the welder. Just get yourself a good extension cord. I am really pushing the settings on my Millermatic 175 (220v) when I weld 1/8" and 3/16" aluminum, I can't see the 110v unit doing very well.

BTW, although Lincoln claims that just changing out the gun liner with a teflon one will be sufficient for welding aluminum, do yourself a favor and get the spool gun setup. Aluminum wire is far too soft to push 10 ft through the gun no matter what liner you have. The spool gun also gives you a little more reach when doing steel work too since it's 25 feet instead of just 10 like most regular MIG guns. (i.e. it's good for doing a pipe rack on the truck). Also, if aluminum is your main goal, consider stepping up to a larger machine like the Millermatic 210 or equivalent. This machine can take a spool gun directly without the need for a separate spool gun controller which would run you extra. You can also have both guns connected at the same time and just choose which one you want to use by pulling the trigger.

I hope that helps you out. I do understand the money issue, but you are asking the same questions about aluminum that I did when I bought my MIG machine. I thought that I could "get by" with my MIG set up for aluminum. Long story short, I'm now practicing my TIG with my Dynasty 200DX. Aluminum with MIG is meant to be done on thick material in production environments. If you get like me and want to do sheet aluminum fabrication, then TIG is the only good solution. It is slower and harder to learn than MIG, but the end product is usually a higher quality.

I know that I tend to recommend the higher priced solutions, but see as how you are in welding school and should have some pretty good skills in a little while I figured it would be worthwhile for you to explore more options since you'll be able to take advantage. Sometimes waiting a little while and saving a little more money for a better machine is better in the long run. Too many times, people buy the small machine cause they can afford it only to plan on "upgrading" later which usually costs more in the long run. BTW, have you asked your welding instructor his/her thoughts on this?

By Mathius (**)

Date 12-02-2003 16:39

I have yet to ask my welding instructor his thoughts on this. We had a break because of Thanksgiving. I'm fairly certain he runs MIG aluminum at home, and uses the TIG for aluminum in class, so he may have some helpful tidbits on this.

I appreciate your help, and I'm not at all discouraged that you told me to wait and save my money. Throwing away money is exactly what I'm trying to avoid.

Thanks,
Mathius

By Mathius (**)

Date 12-02-2003 16:48

What's the general concensus on multi-type welders? I peruse Ebay now and then to see if they have any cheaper used units, and one company advertises a new Millermatic 250NT unit, that will weld in ac/dc stick, ac/dc TIG, or MIG.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2575490643&category=45031

Do these machines generally work well, or do they have strong points and weak points? i.e. is it better for MIG than TIG, etc.? Also, do they generally come with all the hookups? MIG gun, electrode holder, tungsten and pedal, or do I have to purchase these items separately?

Mathius

By OSUtigger (**)

Date 12-02-2003 18:03

For what it's woth, kekoakeakane is right. Don't even attepmt to run aluminum on a 110 machine. My experience with this still haunts me to this day- our situation required a machine that could weld an aluminum tractor frame and components but we only had a small honda generator available for power. I cannot emphasize enough the headaches I had when I found that the frame of the tractor had cracked on its voyage. Two hours were required to make only a few short reinforcement welds due to rat nesting in the machine and the course adjustments of wire speed and voltage. While the welds fulfilled their purpose, they adhere more to the rule of "the bigger the blob, the better the job." Save yourself and buy a 220.

As for engine driven welders, they are the most versatile machines I believe that you will ever find. However, each machine does have its strong and weak points. For instance, the 250NT you are looking at can do all that you would want to and I believe has the 14 and 9 pin hookups required for wire feed modules, amptrols, ect. but, after working with one for about 2 years, I can tell you it has no "specialty." The Ranger 250 that I run will SMAW circles around the 250NT, and is very plesant to run with MIG and SS and Carbon TIG, but has no AC CC output, so Aluminum TIGing is out of the question. Also, no matter what machine you buy, all you will get is the machine itself so you will also have to buy all accesories-e.g. foot amptrol, wire feeder, leads, ect.

Your instructor should be an excellent source of information, as I still rely on my old instructor for information that I cannot find. Sorry about the length, but I hope that helps, and good luck!

G. L.

By kekoakeakane (*)

Date 12-03-2003 02:34

Unless you're a contractor working in remote locations, these engine-driven welders aren't very necessary. The BOBCAT welders are not necessarily considered multi-process welders. They are generators that will do stick and basic DC tig welding. You would need a separate wire feeder to do MIG and a arc stabilizer to do quality TIG. Notice that it will perform "non-critical" AC TIG. There are Multi-Process Welders, but non that I have seen will do AC TIG so TIG welding Aluminum would be out. For the money I would rather get a Millermatic 210 with 3035 Spoolgun: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2576943747&category=45032

AND

a Dynasty 200 DX TIG: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2577154734&category=45031

OR

for less money a Syncrowave 180 SD: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2576513688&category=45031

You would be even money vs the Bobcat and add-ons and these machines will give you better results.