Welding Tips and Tricks

had a few people give advice and whatnot but still cant figure out tig welding aluminum...its not that i dont know how, its that im having an issue with porosity...

1) checked for gas leaks at the tank, welder inside and out, torch back, cup, and back cap...no leaks at all and holds pressure when i put my finger over the cup

2) tried all kinds of different torch angles and filler angles aswell as arc distance...nothing seems to work

welder and specs i use:

miller syncrowave 200 (newer digital model)
bernard water cooler
ck 20 torch
3/32 2% lanthated and 2% ceriated and 2% thoriated tungsten (tried all 3)
#6 and #8 cups (tried both sizes) regular cups, no gas lens
3/32 filler rod, using 4043 alloy (had old rod and bought brand new rod to eliminate any issues)
base material is 6061-T6 remnants from industrial metal supply, de-greased and stainless steel brushed in 1 direction only
100% pure argon from phx welding, ive tried every setting from 10 cfh to 25cfh
balance set from 5 all the way to 10 i do get the frosting when i dont add filler, no frosting when i add filler rod
amps set at 150 to 200 and inbetween, no changes
of course this is set on AC

im sure i left something out but that should be the basics of what im doing...cant lay a nice bead on a flat piece of aluminum on a 1/2"thick steel table, no joints just on the flat metal itself



i can make a weld without filler on the base metal without a single issue, i can use the foot pedal or pulse and create very nice beads

but as soon as i add filler, it all goes to shit, sometimes the puddle will pile up and look like stainless steel crystals or most of the time it will bead but you can see the crap on the top of the weld puddle, after the bead is ran its 100% crap with tiny holes

I would say you have narrowed it down to the filler material being the reason for the porosity. Every 10# box of aluminum filler I have ever bought has had some sort of grease or lube on it. I guess from the extrusion process. I clean most all of my filler and base material with acetone. Although, I know alot of good aluminum welders that have never cleaned a piece of filler and never had a problem.

ill give the acetone a try, i picked up some 5356 filler and i can actually run a bead, however the beat has lots of inclusions but atleast im able to make a beat..so progress maybe? ill have to post up some pics i guess

I occasionally have simmilar contamination issues. I've only been at this for a short while (welding for 25 years - new to TIG) - anyway this morning when working on some aluminum tube, I hit a little spot of contamination. I had to grind the weld completely away and start over. Starts as a little crater that won't fill - doesn't end well. This was after burning a handfull of wire (probably 8 - 10 3/32" rods) without an issue. It looked like the contamination came from the inside of the tube! I'm working on some light wall stuff, it doesn't weld as nicely as the 1/8" wall I've been using mostly.

At any rate, I'd second the acetone treatment and add that I've added cleaning with SAIT non-woven maroon cleaning pads (I keep them just for aluminum) http://www.unitedabrasives.com/ProdDescr/nwag.htm they work and have solved my issues with junk in the welds - now I've got to check the backsides of the thin stuff!

Craig

managed to get a few super clean beads, but most of them are boo boo

i got 2 good beads by feeding the filler rod 100% flat with the base material as low as i can get it, any reason for this??

Hey Canuck, I think the problem your having has to do with the pressure building in the pipe. As the tubing or pipe heats up it builds pressure inside. When you seal up the weld seam the pressure has nowhere to go so it blows the molten puddle out. The best way to fix this is drill a small hole through half of the tube that your connecting to. This will create more volume of air to heat up before it builds pressure. Which should solve your problem. If you don't want, or just can't drill a hole, cool the piece down before you seal the joint up. Leave a half inch or so of weld, cool your piece then finish the weld. Hope this helps. Brian

here is a pic of what im getting....

looks like contamination in your base metal to me. I've been welding patches in an austin healey front shroud, which is 1100 and always full of junk, and the first pass always looks like that. I usually set the cleaning up high and use a squared off tungsten and dance over the area I'm going to weld, grind and wire brush the crap off, then proceed.

well if i light up on the base material, i see nothing but a shiny puddle, however once i touch the filler rod to the leading edge of the puddle, black crud forms on the top of the puddle and mixes around on the top of the bead.

my base and filler are completely clean...im thinking its lack of gas shield from this reason....the filler being too big and not able to stay in the gas stream, ill try a smaller filler on monday...

i also have to overheat the material just to get a good enough puddle to push filler in..my bead isnt very wide so the filler doesnt want to melt into it...however when i do increase the amps and get a good puddle going, it produces bumps on the backside of the metal...could this be exactly my problem?

A friend of mine from Miller calls this "pepper in the puddle" . I notice you dont really have any cleaning action going on outside the weld bead....no frosty band of cathodic etching. That could either be that your ac balance is set too high to give too much dcen, or an argon issue because the cleaning action only goes where there is an argon envelope. adding rod probably accentuates the problem, especially if its too big.
set the ac balance all the way down to about 3 or 30 percent dcen depending on the way it reads. Try all the way up and all the way down without changing anything else.

also examine your tungsten after it cools while holding the torch completely still over the weld. you need a shiny silver tungsten after it cools otherwise, you may have a bad tank of gas or a leak.

let us know,

thanks,

jody

sick man ill give it a shot tomorrow with the smaller tungsten and rod, should work out i hope

1)do you scotchbrite the filler rods?
2) are the alloy numbers close....like a6 welded with 6063, and A4 welded with 4043....?
3) that piece looked like drawn (extruded ) al channel or tubing, they clear coat that crap while it's still hot, it usually takes aluma-brite or acid to clean it really good....pads just move it around.
4)tell your supervisor to get off of the argon hose ,and get back to his job!

well i figued out the issue

i got a decent amount of money and bought another argon tank, filled my old one, got a new flow regulator, and that solved the issue...my guess is 1) the tank was a bad tank of gas, 2) the regulator was leaking and pulling air in


i had some issues with my welder tripping the breaker at 180amps for aluminum so please excuse the stop and start..really pissed me off, here are some DOM steel tubing weld pics with the new gas also

http://www.facebook.com/photo.php?pid=1 ... =851755456

http://www.facebook.com/photo.php?pid=1 ... =851755456

http://www.facebook.com/photo.php?pid=1 ... =851755456

I had the exact same issue. Gas supplier would not believe that gas was bad, good thing gas was pretty low anyway. But anyway it's very discouraging. Good thing you figured it out

I had issues with the diaphragm in my regulator pulling argon in as I was welding. It would leak outwards as soon as pressure deadheaded against the solenoid in the welder, but while welding it would actually draw atmosphere through the back side of the regulator. Fun times.

Just a note on cleaning the rods. (I got the scott- brite thing) I myself keep fine steel wool around for my rods. Hit them with that then the acetone. I clean the hell out of everything, then I clean it some more. I clean my hands like I'm working in a kitchen. THANKS Jack

And after all the cleaning?
How clean are the gloves that Handle the rod/material weld seam??

Mine not so much most of the time.

breaker tripping check all 220 connections

I think what happens with bad gas is tanks get left open when they are empty so they fill with air and don't get purged or properly purged when refilled. X2 on the Scotchbrite on your filler rod.
Have not had the issue personally with welding gas but did with propane. You get a dirty yellow flame mixed in instead of the nice blue