Millermatic 210 can't weld aluminium

[CPUNeck]

I'm at my whits end. I consider myself pretty sharp, and have read a lot on this subject but am certainly no welder by vocation. I could really use some pointers.

Here is the info. I'm attempting to weld up an aluminum tank. Material is .080 (2mm) sheet stock. I have the 3035 spool gun with .030 and .035 aluminum wire. I have a pure argon tank and made sure I have no drafts where I'm welding.

I've tried the recommended #3@50-55 and get lots black burns, if I switch to #2@65 the black turns more to grey. If I up the # or down the wire feed, I loose control of the arc . NONE of these welds look good (globed, moutainous with pores, or not covering the cavity) Sometimes I'll start a weld and it will look good, shinny, coined, but then BAM burn a hole..... I've also tried starting and stopping, man that was the worst. Sooooo, I'm open for help PLS..

I want a TIG machine, is it going to be harder than this???
Sorry for the lengthy post, just wanted to include all the info. Thanks

[Fishy Jim]

I think guys running AL in their migs are using around 25cfh of argon. How much flow are you running?

Tigging AL isn't bad once you get the hang of mild steel. It's harder to see when the puddle is actually there, but other than that, you just get it hot enough and start dipping away.

[harcosparky]

Here is my inexperienced opinion.

At a Miller Road Show the Miller Rep asked if I wanted to weld Aluminum.

I told him I am new and barely confident at welding steel. He said to give it a try. So I picked up the MIG gun and ran a beed. He said " ya need to speed up trave time" So I ran faster and my god I laid down a nice filet joint. I impressed myself.

Now on to TIG ..... OK OK .... it was a total embarassment, but " not bad " for a " first time ".

I don't know what to tell you other then I welded aluminum with the MM210 at the Road Show.

Two things the Miller Rep told me that stuck in my head..... Clean the joint with a DEDICATED Stainless Steel Wire Brush just before you weld it ... even if you cleaned it a half hour ago. And make sure gas flow it proper and no breeze.

I recall reading somewhere if your dog is standing 10 feet from you and wagging his tail you could have trouble. But I think they were exaggerating.

Maybe next week I will setup my 210 to weld AL off the Spool Gun.

[Fishy Jim]

I just use scotchbrite pads in the mini angle die grinder.

[CPUNeck]

Well as to the flow, static was around 22psi. Should I be looking for the 25cfm while the trigger is pulled? Didn't do that.

As for cleaning, I'm in the upper etchelons of OCD... Bought a SS brush just for the AL, tacked the whole thing up good, brushed off all the dadgum black burns, then cleaned with MEK (like aceton) Seemed not to help. I certainly could post some pics on my Photobucket site if it would help. Very frustrating, I've never come across something I couldn't just figure out by reading and practice

Thanks for all the insight

[Sundown]

Turn up the flow to 25, clean well, forget about coins just run a stright bead, stickout should be about 1/2" or more, start with the end of the wire about 1/4" or so from the workpeice, practice until you get the travel speed down, you will be speeding up as you reach the end. Some black soot is no big deal, just clean it off, use 4043 wire if you aren't already. Make sure you push the gun and the approach angle is very importent. If your starts are cold use a ramp or preheat the start area. This is what works for me, milage may vary for others.

[aametalmaster]

Ditto what George said, Keep your joints tight with no gaps...Bob

[ClockWrk]

Aluminum woes

I had a similar problem with that same spool gun. If you take the spool gun apart, you may find that the red tube inside is blocking the shielding gas from entering the nozzle. I had to cut mine back about 1/4" and I never had another issue. It may not be the same problem you are having, but it is worth investigating.

Regards,
Clock

[FusionKing]

I weld aluminum all day everyday except sunday.....4 ten hr shifts on a production line building all aluminum ambulance bodies and then 2 days repairing marine hulls and castings with both mig and tig at both jobs.
In my opinion you are describing a job much more suited to tig. Even if I was to mig it I'm certain that it would have to be set hot enuff to get spray arc and then you would have to move extremely fast....this is on the thin side of practical (.080) even for a pro.
Also is the tank being vented? It has to be vented otherwise it will build up presure and blow out at you. You mention "coined"....that would mean to me you are moving WAY too slow. On aluminum mig with thin sheet material you burn it hot and literally move so fast you almost have trouble seeing what you are doing except by much experience.
I would go so far as to say that for a beginner tigging that project would be a bunch easier IMO.

[Darmik]

Aluminum

i think the spool gun is okay keep using the .035 turn up argon to 20 to 30 cfm stick out should be about 1/2" with about a 5 to 10 deg push and o try using 5356 wire and you are right wire brush the joint that you are about to weld o ya turn up the wire speed on the gun to # 6 I think?


Foot note: I use the 455 stt at work this machine kicks the s#$% out of tigging this machine will weld 10 gage with 1/16 5356 wire as easy as welding 3/4 inch I just love this machine for $15,000. But dont get me wrong I sure love tig work as well if I have time i do tig most of what I do at work when I work with aluminum. O ya tigging takes practice so be prepared to spend some time it will come in time.

[CPUNeck]

Thanks guys, seems I really needed to set the argon pressure with the trigger pulled to get the ~25cfm. On my regulator, that settles into 30-32cfm when not on the trigger. Now I can get at least a bead going. Sounds more like bacon now and the burn marks are a light grey with the point on the bead I just laid shiney silver (if I keep the gun over the weld after I stop welding) If I go that fast I can't ensure I'm closing the gap on the tank. Seems 55 and 3 works ok. Trying to weld from the outside cornor is a disaster, and looks like sh*^. Now I'm not to concerened what the inside looks like, but the outside makes a difference. Looks like I'm in the market for a TIG.