Popping filler rod- on aluminum tig welding

Wow- I suck.
I keep popping the filler rod when I try to start a weld.
The rod end literally goes 'pop' and turns black then drops a big bead of crap on the work.

Sometimes- no problem and feeds fine though these starts are killing me.

What's up- I don't think the rod is contaminated- clean rod- brand new box and seems to work fine once I get going.
Would hitting the arc do this?
I am not hitting the tungsten.

Friggin fight..

Clean the rod with acetone

Keep the rod in contact with the base metal and inside gas envelope

Thanks heavy- "in contact"

Does that mean I should be sliding the rod towards puddle when I start?
When running I usually have rod above puddle edge and dip-lift-dip..

In contact or dragging the rod makes it grounded to the base metal in case you get the tungsten to close to the rod and less likely to suck it up and contaminate the tungsten.I sometimes start my welds like this then once going lift the rod out of the puddle.

Also check the inside of the cup for contamination, it takes very little of the splatters to ruin the cup for use on Aluminum.

Ok- thanks.

I am still at that stage where the torch work is a bloody battle..

If your filler is melting as you approach the puddle, it's a matter of manipulating your torch angle. The arc will bounce off the work kinda like water hitting a spoon. You have to sneak the filler in underneath that reflected arc energy. I had a project a while back doing outside corner welds on .030" aluminum using .035" filler. The slightest inconsistency in my torch angle would destroy the filler before it ever got to the puddle.
Make sure you have at least a 10° push angle with your torch, but no more than 45°. Work the kinks out on a piece of flat material in a thickness you feel comfortable with. Tacking aluminum is the fucking worst. Unless you have perfect intimate contact between the two pieces you are welding, the arc will wander, one side will melt while the other is ice cold. Often I have to stop and restart the arc because no amount of torch manipulation will convince the arc to heat up the other side of the goddamn joint. Once the puddle is established on both sides, it's easy street.
Having done quite a bit of online troubleshooting of my process, it's much easier to get good information if you tell us
--Material type and thickness
--Filler type and diameter
--Machine type and amperage setting
-- AC balance (very important!!)
--Torch configuration(air cooled, water cooled, gas lens or collet body, tungsten type and diameter, cup size, tungsten stickout)
--Cleaning regime of the work and filler(degrease, wire brush, acetone)

Personally, I don't like to keep the filler in contact with the base metal. It's too easy for it to freeze to the work before you can get the proper amount of filler to melt into the puddle. You need to slip the filler into the puddle the same way an assassin slips the blade into his victim's throat.

Watch Jody's videos on Welding tips and tricks for a good visual on proper technique.
Or here's an upload I did today. Lousy cell phone footage, but you get the idea LMF

The AWS forum is a great resource as well. Lawrence and Al (username 803056)are the guys I listen to. They know their shit inside and out.

All good advice above. Another thing I will mention is cleaning.

What kind of material are you working with? Brand new stock or scraps that have been laying around and may or may not have some kind of oil contamination on them? An incredibly small amount of oil, plastic, tape residue, ink or virtually anything with carbon in it can wreck an aluminum TIG weld and make it impossible to get a good weld running. The surface of the puddle should look like wet bright silver. If it is the slightest bit smokey looking, beware... things are not going to go well if you continue. If you see black oxides forming, STOP and clean everything. The black oxide melts at about 5,000F, so it will shield the underlying metal from forming a puddle until it melts and falls out underneath. If you see what looks like a skin flexing on top of the area that you are heating, that is what is happening.

Acetone is an OK cleaner for first round of cleaning, but 90% isopropyl alcohol is the best cleaner and it is not ferociously flammable like many other solvents. You can get it in a quart bottle at Mart of the Wal. Use only a STAINLESS steel brush on aluminum to prevent steel particles from embedding in the work, which can make welding suck and also cause corrosion later on, as the dissimilar metals react electrically. I just buy nothing but stainless brushes, so any one I pick up is fine.

You can't cheat with aluminum TIG like you can with torch or TIG welding steel where you can melt a glob of filler in the surface and then form the puddle with it. You have to get the puddle formed and THEN put the filler to it, otherwise, it globs up and runs off. Above mention of learning how to slide the filler into the puddle without melting the tip off or gouging the filler into the tungsten, or having the tungsten inhale a ball of filler is the skill part of TIG welding and there is no way to get good at it except to practice.

Come in fast and hot on that first dip... especially if the base metal isn't converging at all. If you strike the arc and get the heat flowing and everything starts flowing together before you add filler you are good, if not more heat quick and add filler, gotta get the bead/puddle going.

OK guys.

So the info is here:

--Material type and thickness: 6061 .125" joined to .075"
--Filler type and diameter: Hobart/Maxal #4943 @ 3/32"
--Machine type and amperage setting: Hobart Tigwave set at 125
-- AC balance: "balanced"
--Torch configuration: water cooled with Ck "gas saver" setup- 3/32 2% ceriated, #6 cup, ~1/8" stickout,
--Cleaning regime: Sanding out with DA 180 grit, wipe with acetone, stainless brush before welding


All that said I don't think this is prep-
I am just starting out so ran all sorts of messes to get a feel for the work- laying beads right through anodizing, laying beads with no cleaning, laying beads on oil soaked stock (sucks), etc.

I have a good feel for contamination and with this project I can do ok once I get a bead going.
This problem is haunting me on cold starts.

This is the part:



I got the first fillet run and started to weld up the two tubes over.

Listening to you guys I think I was trying to start too cold- I scare easy so might have been too light on the power trying to not burn through so was not getting a decent puddle to start.

I would try to start a bead, went in with filler and POP- big mess of carbon everywhere and dark granular bead of filler on work.
I would grab a pair of dikes- pry the bead off, wire brush everything down give it another go...

This is all beginners antics but I can't figure why the filler is going to crap- black granular with carbon everywhere..
I also signed up for this- I went right in with a complicated project just a couple of weeks into aluminum tig welding to beat down the learning curve post haste- well it is getting together but I am doing more than my share of grinding to sort out the messes I am making...

How are you prepping your tungsten? For lower amperage work I would grind mine to almost a point, a blunt point. That balled up end shit is for the birds and 200+ amp work where it doesn't matter since your bead and filler are so wide. I have to admit that stuff looks like some gravy work, well fun work. I love running circles around tubes and mostly only get to do it in steel/chromoly.

LOL- "fun gravy work"

Kicked my butt all up and down the road for half a day on Sunday and still not finished.......

Prep- snapping off the tungsten and letting the welding bead it or setting the machine to dc and beading up on some scrap.

On work like that with thinner material like that a fat beaded up tungsten isn't helping... a finer point making a more concentrated arc helps get that puddle going, and make those dips easier. I run really fast on AL, hot and fast. You come in and open up the throttle as soon as the arc is stable and you get that first dip right where you want it. On that type of work putting the bead right where you want it is important... that tall vertical piece will soak up WAY more heat than the edge of those little tubes... so you point the heat up at that vertical tube and reallly lean on the pedal, again that finer tungsten point will help "pierce" the puddle into forming and then you bring it down into the thin edge and dab. Once you have that first dab and a puddle running you point the heat a little up at that vertical tube and it runs down into the thin tube.

What size tungsten would you run?
A 1/6" will do the weld but melts back over time, a 3/32" will bead up but I could start out with a grind on it..

Here is an excerpt from the AWS handbook that shows the relationship between tungsten taper and penetration. A sharp long taper makes a broad and shallow puddle, and a blunt taper makes a deeper puddle.
Don't be afraid of the heat. Aluminum conducts heat very well, and so it is more difficult to establish a proper thermal gradient in the work, which is the only way to have control of the puddle. For .125" material, try 150 amps, stomp the pedal and get in there. Once the weld is established, you can back off the pedal 10% or so. If you try and sneak up on it because you are afraid of melting through, you will have nothing but trouble. You MUST have as steep a thermal gradient as you can get.
Forget sanding as a part of your material prep, it isn't helping. You will not make any progress trying to weld on anything but pristine metal. My students used to ask "how clean should I get it?" to which I would reply "Pretend you are making your grandma a bowl of soup, and the only spoon you can find is stuck in a pile of bloody dog shit. How clean are you going to get that spoon?" Wire brushing 3003 or 5052 ain't so bad, but 6xxx alloys typically have a thicker oxide layer to clean off. After years of wire brushing that stuff, by hand using strokes in the same direction mind you, I have started using a scraper to clean 6xxx material. Grind it to a fine edge and then use a stone to get it even sharper, and it goes quicker than with a brush.
You have quite a challenging workpiece for being new to aluminum GTAW. Work the kinks out on .125" 6061 before you try a complex joint like that. And make it CLEAN. The three C's of aluminum welding are Clean, Clean, and Clean. If it isn't clean, then the three C's become "Cunt,CUnt,CUNT!!"

Try using an AC balance of 65% EN. Anything higher and you start to lose the cathodic etching that is necessary to a clean puddle. Around 60% or so, and the tungsten starts to overheat. Maybe try a 1/8" tungsten if you like the AC balance at 50/50.

Definitely crank your machine up. I'd run the panel control at 150-175, so I had burst heat for starting. Zap hell out of it to get the arc stabilized an get the puddle formed quickly, THEN back it down as required. I keep my panel amperage high enough that I never bottom the pedal, gives more total control.

As brianweldor says, dial up your balance to a little past neutral (the white mark on the dial). That also helps prevent blowing through.

Did yiu mention what gas you are using? Sounds stupid, but you are using pure argon, correct? As the other guys have said 1)clean!, 2) AC with high freq on continuous, 3)sharp tungsten, 4) enough gas flow, I typically set mine high, around 20 cfm or more, 5)get a gas lens for your torch if you don't have one 6) I assume you meant "4043" filler. You'll get the hang of it! Aluminum is all-or-nothing, it either runs great, or absolutely hellacious.

If it runs bad more heat... counter intuitive. Hotter faster, hotter and faster, until it stacks up and rolls out how you want, needs that flow. Also if you are used to doing a lot of steel, or SS you gotta dip faster with AL. I love welding SS and Chromo because its so relaxing, you work the puddle slow and minimize heat and dab lightly. On AL you gotta fly and almost drop the filler into the puddle as it melts off.

trboatworks, I forgot to mention your fit up looks beautiful. That is usually the source of a bunch of problems with Al, but you'll be just fine once you get the heat figured out

Ha you guys got me laughing about the bloody mess I made.

Did I mention I scare easy?
I think I have been running cold and scared and that beautiful fit up kept getting covered with a lumpy mess as I tried to sneak up on it.

I'd grind the crap down and if the weird filler popping didn't get me a new lump needed filled down- what a bloody fight...

The arms on that fit up are 30" long which was playing havoc with me trying to roll it over to reach everything.

I did say I wanted to beat down the learning curve LOL...

Yes- pure argon at 20
Filler is 4943- I was researching Al tig welding and liked what I saw so thought why not and bought a box:


"Insufficient dilution can be a concern with alloy 4043, which can result in low weld strength. Alloy 4943 significantly reduces the impact of dilution on weld strength in as-welded, post weld aged and T6."
http://www.maxal.com/4943_datasheet.pdf