Aluminum contamination

[vr6chris]

im having issues lately with contamination with aluminum. starting off, using a miller dynasty 200 dx. 2% puriated tungsten and i clean the material well. having issue to where i start the arc, but as soon as i add filler, it ***** up in a black puddle and looks horrible. my tank is almost done, so i need to go get it filled up again, so im wondering if the argon i have is contaminated. im using a gas lense and tried 2 different tungstens sharpened on a dedicated wheel. only been having this problem the last 2 days.

tia

[B_C]

I just welded a badly cracked transmission case (bell housing section) and other than die grinding out a groove for strength and lightly cleaning the area to be welded all I did was set the machine toward the cleaning cycle and use 75-25 argon helium mix and 4043 filler ..........It came out cherry......I don't know what your doing wrong but that set up has worked for me hundreds of times?

Tungsten size for thick aluminum is always at least 1/8" I use 5/32" with the big torch (WP-18)

[vr6chris]

yeah, im wondering the same thing. this stuff is not dirty either. its .065 wall piping. i clean it with a dedicated stainless wire brush. but i know thats not the issue. im just wondering the argon im using is somehow contaminated. its almost out anyways, so i think im gonna change out the tank tomorrow

[SundownIII]

First thing I'd do is get rid of that "puriated" tungsten and get my hands on some 2% lanthanated tungsten. Some use thoriated (BC for instance) but I've had better luck with the lantanated.

Swap out that bottle and give it another whirl.

[SundownIII]

Went back and reread the post.

You may in fact have some contaminated filler. Filler will oxidize same as your base material.

I generally will clean my filler (if I'm being real particular--like a clean room) with scotchbrite and then wipe it down with alcohol. You may want to give that a try.

[fillncap]

it could be your tank getting low.i had a similar problem a year or so ago and the problem with me was the bottle,the company i got the gas from said the bottles do contain a percentage(max 1 %of tank volume) of porous mass/contamination in the bottom of the tank.

check the hoses are all tight and there is no leaks ,even make sure the tig neck body is tightend properly.

if your machine has a pre gas flow setting turn this up so it is set to around 2sec.

fnc

[walker d.]

plus i dont use a gas lense when i'm welding al. they dont last long. they tend to burn up or deteriate . might be some thing to look at just a guess. that could be some of the problem. when they burn like that they seem to blow your gas down one side of your cup. at the ammmunition plant i work at whem we weld alu. we take the gas lense out

[[email protected]]

VR6Chris,

This may sound dumb, but I have the same machine and just started welding Aluminum, I had on a couple of occasions the same challenge and found I didn't have a "good" ground (my Aluminum was not well grounded to the metal table that my ground lead was attached to) Just a thought.

as well I tried (once) to use a gas lense on AL and it didn't work well, I went back to a standard nozzle/collett and cup. 3/32 2% Thoriated tungsten (plan on changing out to Lanthanated or Ceriated) next time I get to LWS.

Tim (thanks to the help I am getting on this board I am slowly getting R done) "still not yet pretty"

[vr6chris]

thanks for the advice guys. as for grounds, clamp is grounded to 1/4" thick table and never had any issues before. i swapped out filler rods and cleaned before using so thats not it. also, the puddle before even adding filler rod seems contaminated. im gonna swap the tank out today and hope for the best.

and about using a gas lense with welding aluminum i have read its best not to do this, but i have welded a lot of aluminum with the gas lense with no issues.

and some pictures of my recent work.

downpipe

Engine

downpipe


surge tank i made
Surge Tank

Manifold


and the welding setup
Dynasty 200dx

[vr6chris]

well, fixed the issue today. started off getting a new tank of argon. old was near empty anyways. go to weld, same issue. turns out one of the lines was kinked. dont know how it happened, especially since i didnt move the welder in the past month and it just started happening 2 days ago. but oh well, all is good

[Pangea]

With the tungsten removed or retracted, put your thumb over the end of the cup and press firmly. Bump the foot pedal to initiate the gas flow. Watch the flow meter. If the ball stays down, you have no leaks in your system. If with the cup sealed tightly with your thumb, the ball raises and stays up, you have a leak in the line somewhere.