aluminum troubleshooting

[mschlee]

have a new 190 with spoolrunner 100 gun. put it together with 100% argon tank and 4043 .030" wire. trying to dial in the settings on some practice pieces of 1/8" 6063 (pretty sure as it is square tubing and corners are sharp not rounded) i'm having trouble and hoping someone can help.

started at the recommended 5/80 but it was burning through and welds were really flat. also had a lot of soot. played around and this is the trouble i'm having and questions:

1) power setting: seems like power at 4 gives a better weld (not too flat and not too high), temperature makes a huge difference as the start of the weld doesn't penetrate well and after about an inch it is better and at 3 inches or so it is way better. what is the best way to preheat? using map gas torch takes forever.

2) wire speed: this is my big challenge. i'm following the advice of longer stickout (3/4" or so). if i lower the speed down to get the nice hissing sound rather than the frying bacon sound i start burning up tips like crazy. if i watch the tip during the weld i see the wire pulsing shorter and longer rather than a constant length. not sure if that is normal but thought it was strange

3) soot: no matter how much or how little argon i use the weld is still full of soot. i was thinking i'm holding the tip too far but if i get too closer again i burn tips like crazy.

i assumed it would take a while to get it dialed in but the rate i'm going through tips can't be right.

any help is much appreciated

[garygnu]

what angle are you holding the gun at ? you want about *10-15 degrees of tilt ,pushing the puddle .

[mikecwik]

Welcome to the forum.

Go to another forum such as weldingweb and seek help. This forum pretty much sucks and I take full responsibility for it.

Don't worry about the soot. 1/8" is thin for a new guy but struggle is a good thing. No need to preheat with a torch or even goofing around with the welder....I just never liked the idea of it.

[gatemaker]

soot

Most of that soot is probably from anodized or dirty AL. Try scrubbing it with a clean scotchbrite pad or a new stainless steel brush. Dedicate a brush for AL only. A dirty brush will make things worse.

[mikecwik]

http

I guess images of the soot would help maybe. For the most part I don't think it is going to bother anyone it can at times embed in the weld a bit and create pits. I can't get technical about it.

[mikecwik]

Not liking the MACBOOK AIR SO FAR.........

[weldaway]

Pending on the type of soot, it's not always a bad thing just the nature of welding aluminum. Magnesium is an "ingrediant" of aluminum, some grades contain more than others. When you weld the magnesium burns off and creates a soot like substance on the edge of your bead.
Another possibility is your penetrating through the tube and pulling impurities from the opposite surface area and atmosphere you are welding on. Your shielding gas cannot reach that area. What kind of liner are you using? What size tip?

[mschlee]

thanks all. been playing with settings a lot and things are starting to get better - still soot though. moved up to .035 wire and seemed to help. i'll try to get some pics up shortly.

[calweld]

First question, are you pushing or pulling the weld? Pulling will almost always cause a lot of soot.

As previously mentioned, CLEAN!! And weld as soon as possible after cleaning. Scrub with a dedicated SS wirebrush, wipe with a clean dry rag, then weld.

A comment about settings, they are just recommended starting points. Actual values you dial your machine depend on many factors, including your own welding style, power company's input values, stage of the moon, etc. etc. Adjust up or down as necessary.

Understand, for proper aluminum mig, you do need to run hot and fast. You may just need more practice and arc time. If you are used to steel mig, there is definitely a learning curve when switching over to aluminum.

About the burning tips issue, are you using the right tips? I believe both Hobart and Miller supply special tips for aluminum, slightly oversize, I use a different setup so I don't know for sure. I think you do need to make sure you don't have the drag set too tight on the spool, and you do need to increase your wire speed.

Oh, and by the way. Ignore Mikecwik's first post.

[mschlee]

thanks all. things are looking better. yes i push not pull and have been going crazy with the settings - wire speed, gas, power, tip length, angle etc.

the .035 wire helped a lot. i have not burned a tip since i switched (only did an hour or so welding but still much much better).

the soot doesnt really bother me as i can just ss brush it off. it is weird though because if i turn the gas off it spatters all over as expected. but once i turn it up to about 10 i can keep turning it up to max and dont really notice any difference - strange.

one thing i would like to do is get rid of the cold starts as there is no penetration and the weld is just piled up. how do you guys preheat? i dont have a/o and dont really want to spend that kind of money just to preheat (plus i dont like the danger factor). i was thinking a propane roofing torch might work? i've seen pressurized air propane torches but they look pricey too. - what do you guys recommend?