Hello everyone, I am welding 2x2x.125 6061 aluminum and I've hit the ends and edges with a flap disk, red scotch bright and acetone but I am still getting black stuff floating in my weld. I've changed tungsten cleaned the filler metal and some spot are clean but most I can see it coming in. Just have a lot of parts to weld together and don't want to use a wire brush. I am using a dynasty 210 on 200 amps, balance is on 70 percent, gas is at 15 cfh and i am using a gas lens, number 6 cup and a wedge collet.. Is using a flap disc putting the oxide layer into the aluminum and that's my problem?

Just a couple of things. Are you using a flap disk designed for aluminum? I have had good results with a soft stainless wire wheel (available on amazon) on a die grinder or battery drill. with that you can clean an area just slightly wider than the weld zone. Assuming your torch angle and stick out are good you might also try bumping up the gas flow just a bit, be careful not to go to high. If you have extra material, you might set up a few joints and try the new procedures and gas flows until you get what you need. One last thought, is your Argon bottle near empty or full, may be bad gas. good luck

I got the disc as a promo from a Weiler rep sorry the label has come off. A quick search on the web gave several options from most of the major manufacturers. Amazon has a few options, but I can't vouch for their quality. Most welding supply stores carry them. The settings I use for that material thickness are 110-120 on the frequency, 140-150 amps (foot control), 65-70 EN on the balance, 15-17 cfh argon with a #5 standard cup and 3/32 2% lanth tungsten. Probably not to different from your settings. One last thought, I ran into some bad wire the other day. Turns out it was old and oxidized throughout the wire. Got some fresh and everything cleared up. When you find the solution let us know.

red scotch brite pads have lubrication embedded in them. Brown is ok for cleaning.

I agree with Brian. The red scotch bright pads can be a really big problem when used for prep. They should really only be used for post polishing. They do have a polishing compound of some kind in them. The course Brown pads do not have any compounds. I have used them on many weld tests that have passed x-ray. Give them a try and see if there is any change.

Once you go brown...The porosity goes down...😑

Wow that's a key tip with brown vs red, I didn't know that. Glad to find that out.
I think it also helps to wipe with acetone prior to grinding, not just afterwards. Aluminium is so soft that really any crud on the surface of your workpiece in the moment that you grind it is liable to being forced or smeared down into the metal. Takes an extra step but it's definitely always my preference to wipe down before any kind of mechanical abrasion and then give a wipe afterwards too which should really take off dust more than oil at that point.