Mike454SS

iTrader: (4)

I'm welding all of my intake piping together, and I'm not as comfortable with Aluminum as I am with steel and stainless.

It's right around 0.065 wall thickness tubing, and it's all butt joints. I'm having trouble getting the 2 pieces to puddle together when I first start my arc, it's much easier with steel. Once I get it going I find it works just fine...just getting the puddle started properly is giving me a headache, and the beginning of my welds don't look so great.

Anyone have any tips/tricks/suggestions for welding aluminum pipe? How does the "AC Balance" setting apply?

y2khawk

iTrader: (5)

are you using any filler on the initial puddle, or just relying on the base metal (easy to do on steel)?

what size electrode and what do you have the machine set for current and balance wise?

Base metal clean? inside and out??

Mike454SS

iTrader: (4)

I'm trying to use filler for the base puddle...3/32" ceriated (orange) tungsten, I have the balance set low (been playing between 30 and 40...but I don't know what the units are, and I don't know how it affects the weld, but lower seems to make it puddle better), I guess it has to do with "cleaning" but I don't understand (hence asking for help).

I have it up around 90 or 100 Hz I think (it can go down to 60, but it seems to be a more stable arc at a higher frequency).

I have the machine set on 100 amps peak, I'd say with the pedal I'm probably using 70 or so, pure argon at about 20 CFH.

I clean the work before I weld starting with a wire brush (I have one that I only use on aluminum) and then I wipe it clean with acetone...should I be cleaning it some other way?

Like I said, once I get it going it actually moves along really well, I can make some really good looking beads, I just can't get it to start properly. It's kinda discouraging because I don't want to have a bunch of intake piping with ugly welds, I'm an apps engineer for Haas automation's local branch, so I have all kinds of cool looking stuff going on under the hood that I cut in CNC's (and I'm a bit of a perfectionist with everything I cut/machine) so I'm trying to get my welds to match...it's weird, I can get stainless and other steels to start a LOT easier, but my beads in aluminum look better once I get them to start.

Going with how much of a perfectionist I am when I cut anything, I am not trying to fill any enormous gaps either...all the pipes fit VERY VERY nicely before I weld. I've tried butting them together straight as well as putting a chamfer on them...but it doesn't seem to make much of a difference. I'm still only practicing, haven't gotten to my actual piping yet.

Thank you for the help.

Phil99vette

iTrader: (11)

Aluminum is pretty easy now. Harlan filled in the last piece of the puzzle which was cleaning the inside of the pipe. Here is my procedure

200 grit wet/dry automotive sandpaper
Sand edge, inside and outside ~1/4-1/2"
Acetone 3 edges until no black residue comes off

I used to wipe the filler rod with steel wool or scotchbrite pad and than acetone but now I just wipe it with acetone until no black appears.

1 amps per .001

Dynasty 200dx with pulser
Balance: 70ish

120 hz

get your puddle in the material and dab your filler

Aluminum with the oxide layer will pull away from the weld

Mike454SS

iTrader: (4)

Cool, I'll bring the balance up a bit...after that it sounds like I just need to practice more. I'll go to sandpaper instead of the wire brush too...I've been working inside and out with cleaning, same thing too, till no black appears...thank you.

MikeGyver

iTrader: (5)

Along with Phil's settings, I would raise the amps for more starting horsepower.

01ssreda4

iTrader: (96)

^^^plus one. give it some juice to heat it up.

y2khawk

iTrader: (5)

you shouldn't need much juice for .065 tube. Really much more than 1 amp per .001 on that isn't really needed. Thicker stuff, i end up cranking the bitch up to 300 and let her rip Helps to have a big machine

I also tend to stick with pure tungsten on aluminum, but I'm on an old school transformer machine. I like the wider heat area with the balled electrode myself, but to each his own.

I will also use 1/16" tungsten on the thinner stuff.

quicky info on balance, aka clean/dig.

0 to 100%, 0 to 10, whatever your machine calls it.....

you are adjusting the amount of time the work is the positive side of the AC wave form and the tungsten is the negative. 100% and you're basically working as if you had the machine set on DC - for steel.

Crude description to follow.

when the tung is negative and the work is positive, electrons are jumping from the electrode to the work. Putting heat into the metal you are welding. when the AC wave form flip flops, you are sending electrons from the metal to the electrode. Basically pushing all the crap on the base metal off and on to your tip (the cleaning portion). that's what causes the white border around the weld.

100% dig, work positive/tung negative, and all the heat goes into the metal. thinner beads, not so hot for dirty metal.

0% and all your doing is melting the tip and contaminating the electrode.

I tend to run about 60 or 70%.

Aluminum MUST be clean for nice welds. If you use a metal brush, use a stainless bristle and dedicate it to only aluminum. If you hit mild steel with that brush you will pick up mild steel on that brush and put it into the aluminum you are trying to clean.

also, alot of aluminum will have a mild anodize or coating to it. This can make a mess of the weld as well.

Best thing to do it get the joints as close as possible and clean. put some heat into both sides, using the torch to direct the heat and get a puddle started on both sides of the joint. once you've got some heat into both pieces, use the filler to join the puddles. Once theres a bridge across the joint, the rest is easy. So to speak

practice makes perfect, is the best advice though. I've been at it for 12 years or so and it's just kind of second nature anymore. But it's always good to practice on scrap pieces if you want to try something different.

01ssreda4

iTrader: (96)

isnt green tipped tungsten better for aluminum? he said he was using orange.

Mike454SS

iTrader: (4)

Miller's website is why I'm using the orange...but I'm open to suggesstions. I'm using a Dynasty 300...so it's not a big old transformer machine, but it is a NICE TIG...I agree, once you get it going the rest is easy.

Thank you guys very much for the help, I really appreciate it. Hopefully my intake piping will look good once I've done some more practicing.

I think I might try to find a class to take on TIG welding...I'm really pretty much just self taught...I think I do pretty well considering.

black4x4

iTrader: (3)

Green is pure and is what I have used for aluminum when welding it, but the orange should work just fine. And for me the biggest problem with starting a puddle is making sure I have the torch at the right angle.

jdustu

iTrader: (2)

Green, orange, red.....it's all good. They say to stick to the ceriated(orange) with the invertors, but I've been using 2%(red) as well on my dynasty. At work we've got a synchrowave 350(transformer) that they say to use green(pure) on aluminum, but I've had plenty of success with both red and green. Sometimes you can notice different arc characteristics, but usually you'll be ok. Some guys swear by certain tungsten, and sometimes on specific certs one will cleary help over another, but for general purpose it shouldn't be too critical.

y2khawk pretty much hit everything dead on. I've got a little die grinder with a scotch brite roloc disc that i clean AL with, and I swear by it. Cleanliness is godliness when it comes to aluminum welding!

LS1_4seater

iTrader: (3)

If after you have cleaned and cleaned you are still having problems use a propane torch to preheat the metal a little.

brandons02

Yeah its probably crappy aluminum almost like cast, I TIG weld aircraft in the Marine Corp and if you preheat with a torch as previously stated it welds beutiful. May take while to preheated and if that doesnt work, take you high frequecy, the first small arcs that shoot out when you barely pree the petal and drag them back and forth accross the area to be welded. Makes it alot easier.

jdustu

iTrader: (2)

You really shouldn't have to preheat anything that thin. It's probably not a big deal in this case, but preheating aluminum weakens it a lot. Not that I haven't done it with the HF like you described plenty of times

I second the crappy aluminum though. I've had pieces that looked fine and were the right grade and everything that just wouldn't weld worth crap. I know some guys that have toured different refineries and whatnot they talked about how much junk gets into some of the stuff. Aluminum is so touchy to contaminants anyways with welding, which is why cast aluminum can be funny.

Mike454SS

iTrader: (4)

Nah it's quality pipe...it welds fantastic, I just needed some advice and practice...it's turning out really nicely.

MikeGyver

iTrader: (5)

Well if you're going to brag, then we must insist on pictures.

z28berryhill

iTrader: (26)

what i do is melt some filler on the seem bfore it puddles the metal then melt it in thats just me i hate aluminum

Drew04GTO

iTrader: (1)

I've had poor luck with this, but I'm not using HF or anything. Using my miller econotig (only weld aluminum once in a while) I find it best just to give it everything its got and be quick with the filler. Like stated before, get a puddle on both sides of the seam and I usually kinda swipe across the two as I dip it in for the first puddle. God how I'd kill for an inverter welder.

jdustu

iTrader: (2)

true dat!

The dynasty makes aluminum its bitch

If you get a puddle going on the joint, the filler will suck right into it. Ideally you want to keep the end of the filler in the gas protected area too, so if you're dipping it, don't jerk it in and out too far.