MIG Aluminum LE 180C & spool gun

[Arbogaster]

Hey guys this is my first post here and let me just say I've been lurking for quite a while and soaking up a bunch of good information. Thanks for a great forum to share ideas and techniques. OK heres my question. I've got a new Lincoln Electric 180C with the spool gun for doing aluminum its a 220 machine. I have no professional welding experience or formal training I've just been stick welding and MIG welding things for a few years on the farm repairing and building small things. Nothing critical just stuff to learn on. My settings on the inside of the machine call for the current and wire speed to be set at a given value ( like 3.5 and G if I remember correctly). When I try to weld at that setting it blows through. It does not matter how fast your travel speed is it just makes swiss cheese out of the material. When I back down the current setting about 2-3 notches I start getting a weld that I can control and a travel speed that is reasonable. I leave the wire feed speed alone or maybe back it off just a touch. About every third weld I do looks decent and the more I do it the better they look. So my question is why does the cheat sheet sticker on the machine call for such a high setting?

Background info. On every weld I make sure to do the following in this order.
1. Wipe weld area clean with a clean rag and a little carb cleaner
2. Brush area really good with a clean stainless steel "for aluminum welding only" wire brush
3. My gas is 100% Argon set on about 30 cfh
4. My tip is recessed in the gun about 1/8"
5. I'm using a push technique
6. My gun is about 10 degrees off perpendicular leaning away from the direction of travel.
7. My welds are always horizontal when they can be.
8. I always cut off the blob on the end of the wire before starting a new weld.

I know my setup is not ideal for aluminum but it does work and will get me by for my use. Any tips, tricks, or ideas would be greatly appreciated.

[Rojodiablo]

Back the gas down to 20, and turn the speed up, up, up!!! Aluminum mig goes very well, but you will weld about 2 times as fast as with steel. Also, you did not say how thick the aluminum you are welding is. I have a Miller 175. For heat, I run between 4-7. For speed?? try 6-9. Basically, get a puddle formed, and start running.

[Arbogaster]

Ohh good point! The material I was welding was 14ga aluminum square tubing, and flat stock. I have found that welding the thicker stuff was easier but I'm still figuring this out. I have figured out that when welding aluminum you have to haull a$$ compared to steel I just don't have a good feel for it all yet. Any idea how your numbers compare to my letters as far as the settings. Most of what I have read says that you want to be in spray arc transfer mode for aluminum but for the 14 ga stuff it just doesn't work its too high.

Thanks for the help!

[weldgault]

Most Mig machines will not let you short arc Aluminum, because the volt/amp curve and short circuit current of the power supply is to high. You can weld 14 ga in the spray mode but you have to travel. You will get it, because you have the basic knowledege, practice " " " " " " ". John G.

[Rojodiablo]

Try some extra stickout on the wire. It will cool the weld as you go. I will start pretty close to the material to get the puddle going, then as I run, I will pull the gun further from the workpiece to cool the current a bit. If it gets a little too cold, I dive back in closer. You will find you manipulate an aluminum mig weld almost as much as a tig weld!!!

[weldgault]

Originally Posted by Rojodiablo

Try some extra stickout on the wire. It will cool the weld as you go. I will start pretty close to the material to get the puddle going, then as I run, I will pull the gun further from the workpiece to cool the current a bit. If it gets a little too cold, I dive back in closer. You will find you manipulate an aluminum mig weld almost as much as a tig weld!!!

Where you increase the ESO you increase the Voltage making the puddle more fluid (Heat). Sorry for the correction, but it was necessasry. John

[turboblown]

If your MIG gun allows, pre and post-purge the weld for a few seconds.

Don't weave- go straight.

Pre-heat large pieces

I use .030" wire on something that size unless using pulse, then I use 3/64"

When everything is just right, you'll get a shiny bead with white around the edges that looks like something that was tigged. I also experience a "correct" sound that you can go by.

One thing I do is lighten up on the face shield tint. I can MIG aluminum better with a lighter glass. If you are going to do a lot of Al MIG, look into a unit with pulse. It takes a while to get set, but once you do, sweeeeeet!

[tapwelder]

I have the 180c and spoolgun also. I haven't used it much. It does work better in spray mode, however.

[Rojodiablo]

Originally Posted by weldgault

Where you increase the ESO you increase the Voltage making the puddle more fluid (Heat). Sorry for the correction, but it was necessasry. John

I don't know about that. Every time I pull the tip of the gun further from the workpiece with mig, I get a definitely cooler weld. If I want a more intense puddle, I will crowd the part with the gun, and use a lot less stickout. But you've been wrong before, so I'll just go with it.

[WeJeep]

Spay arc vs Short arc?

Update: Never mind. I found the Sticky posted by ZTFab with video and all.
This has got to be one of the most friendly comprehensive sites I've ever read through. Thanks for all of the great information. Jut getting started with MIG.

[weldgault]

ROJO, I started to answer your insult, but it's not worth it. You will learn. John

[Arbogaster]

Hmmm? No weave just run straight . . .I'll have to try that, I was getting some of my better results with a little weave. I'm using 0.30 wire, my tip to work distance is probably 3/4" to 1/2". What kind of a sound am I looking for? When I was in spray transfer on the thicker stuff It was just a high pitched hiss, ohh and it kept burning back onto the gun and melting the tip. With the thinner stuff I dial it back and some of my better welds sound like the frying egg some guys describe but less crackle and more of a consistent sound. I need to post some pics for you guys to look at and diagnose. I'll try that tomorrow. You guys are great thanks for the help. I know I suck at this but I'm having a good time learning.

[Rojodiablo]

Originally Posted by weldgault

ROJO, I started to answer your insult, but it's not worth it. You will learn. John

Well, look at it this way. With any DC current, the longer the run, there is a voltage drop. That is why, in simple terms, you put the battery close to the engine, so you don't have a big voltage drop from the battery to the starter. Ands, to get a little closer to welding, the wider the gap on a sparkplug, the cooler the plug runs. The tighter the gap, the hotter the plug runs. With tig, same deal. A good hot arc is best formed with the electrode as close as possible to the workpiece. And, so with mig, the thickness of the wire and the stickout will certainly guage the amount of current that carries across the mig wire to the piece. The longer the lead, there is a loss of energy, as it is wasted in basically traveling the extra length of wire. The thin mig wire will not carry the load as well as the cunductor/ tip in the gun, same as a 14 ga. wire will not carry the same load as a 10ga. wire. If you have 1/4" stickout, you will have a very hot, concentrated arc. If you have 5/8" stickout, you will not have a hot, concentrated arc. You will in fact have to work pretty hard to get a good controllable puddle formed.

[Doug247]

Im with rojodiablo,the Voltage increases when the tip is closer to the work. when you hit that sweet spot with the wirespeed and voltage you can adjust your angle tip to work distance and travel speed and, well, your damn rights its a sweet spot! i started welding aluminum this week building house boats and accessories, and they have already taught me so much abput working with this material. i just dont understand why we use .045 for welding everything when we do 1/8th-3/16 material most of the time.
some tips ive learned is when you are done your weld dont wipe it off with your glove it stains the weld, instead wire brush it and wipe it off with a rag it, makes it look pretty. when welding tubeing solid, drill a hole to let the gases escape, if you do not you may have a have a blow out. cold lap is so easy to make with an aluminum weld, dont make cold lap. lol.
if you have a knak to welding you will catch on. those guidelines inside the machine are just starting points, looking forward tosome pics

[turboblown]

The sound I experience is a clean hissing sound with very little on no crackle like when doing steel.

[Rojodiablo]

Originally Posted by turboblown

The sound I experience is a clean hissing sound with very little on no crackle like when doing steel.

You are getting into spray arc mode. NICE!! Spray for aluminum is a much better way to go once you can get it set up right.

[turboblown]

If your machine is capable of the voltage, do spray for sure.

My small unit can only do short arc. It doesn't penetrate well and is sloppy. It's almost useless.

[Arbogaster]

OK here are a couple of my welds. Do not hold back on the critique. I am learning and I know I am not that good at all. Any observations or tips you can hand out would be appreciated. I have already taken into account some of the suggestions already made and will apply them to my next welding practice session. Don't worry about the piece in the picture it is for a small door that hides my battery compartment on my boat and its welded in about 8 places. It's not going anywhere and nobodys life is depending on it not to break.

Thanks guys