Best Method to clean AL metal after it is contaminated with oxidized rod?

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One of my workers has this bad habit of trying to stick the rod into a fillett joint before the puddle is formed. The AL filler rod turns into a tiny bead, badly oxidized and then contaminates the weld on 1/16th square1x1"  tube aluminum. I caught him putting the tungsten directly over the little bird turd he just made and trying to melt it into the metal. I quickly told him that wasn't going to work!!!Obviously he needs more practice, but I'm wondering if there is a best way to clean up the weld area? I've tried a stainless steel tooth brush, but that still leaves some dark spots and rewelding leaves porosity/oxidiation issues. do I need to get a stainless steel wheel for my angle grinder to really dig that contamination out? the metal is only 16 gauge.Maybe it's just toast and I should scrap it so he can run more practice beadsI did search and found this thread which was very helpfull in explaing how feed rod gets oxidizedhttp://weldingweb.com/vbb/showthread.php...t=contaminatedbut many photos were missing from it and it didn't really address trying to fix the contamination.Last edited by AluminumWelder; 12-17-2012 at 11:23 PM.
Reply:Good way to remove bad alum is a carbide burr on a die grinder. Don't go with a SS wire wheel on a grinder. All it will do is smear any contaminants..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:thanks i dont' own a die grinder, but I think my little dremel tool with carbide tip would work!
Reply:Yup, got to grind/cut/get it out, a wire wheel will just push it around.
Reply:Hey A-W,Here's a superb air micro grinder from HF I use instead of my Dremel....has way more power & won't heat up. A Dremel just doesn't have the lasting torque for many grinding jobs & wasn't designed to. I picked this one at my local HF on sale for $9.99.....best $10 I spent. It also uses 1/8" Dremel shank burrs/drums/stones. I run at 60psi. Here's a pic....Denny Attached ImagesComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:very cool I think I have burned through 5 to 6 dremels in the last few years, they are not cheap to buy but they are cheaply made. this will hopefully last longer and if not I'm not gonna sweat the $10 price.also curious if there is an adapter that lets me use 1/8 shanks on a 1/4 die grinder. Turns out my buddy has a 1/4 die grinder I could borrow, but I only have 1/8 bits.Last edited by AluminumWelder; 12-18-2012 at 08:39 AM.
Reply:Die grinder with a decent (doesn't even have to be great) single cut burr will cut through aluminum like butter. I usually use a ball shape to gouge out bad welds. They can be had for pretty reasonable prices $10-$20 for a cheaper one with a short shank. Don't get a double cut burr for aluminum, unless you want to constantly keep lubricating it, otherwise it will load up all the time and end up slowing you down. WEAR SAFETY GLASSES, it will send sharp shards of aluminum all over you. I've had them literally stick in my face. No way would I want that in my eye.
Reply:You can get cheap die grinders at HF too.  I use the crap out of them, barely oil them and they still seem to run forever.
Reply:The more expensive of the two 90-degree die grinders (1/4" collet) at HF works very well (I think it is in the $20 range).Kevin / Machine_Punk from The Aerodrome Studio - Lincoln PowerMIG 210 MP - Meco N Midget w/custom welding station - Vintage Victor 100Current Projects: The Aerodrome Studio
Reply:Okay, a hint or 3 to help your guy not do this in the first place: With clean material, and the gas set at about 13-18cfh, have him start a puddle with these settings: Amps- 140. Freq. 75. Balance-70. Upslope time- 0. Downslope time- .1 Pre-flow gas-1 second. Postflow- 8 seconds. Okay, here is what he will do: Set up, and mash the pedal to the floor. The amps are high enough that he will get a puddle RIGHT NOW. He then backs off the pedal, and the puddle will be there for him, clean and easy to see. Dip the rod in, on the side of the puddle, and then smoothly pull the rod back out. Let off the pedal completely. It's a single dab. He MUST learn this for thin material.This is how you start. Once you understand to make that one puddle, then you can learn to hold an arc and move forward, and add dabs as you go. My recommendation; Once he can make this puddle 10 out of 10 times, he should practice making multiple puddles this way, one after the other after the other. Light it up, a dab, and drop the arc. He MUST learn to keep the gas on that bead he just put down. Gently wave the little wand over the length of weld for the 6-8 seconds. He MUST learn this, 10 out of 10 times. After he learns this and can do this 10 out of 10 times, then he moves on to lighting an arc and traveling the puddle and adding dabs. Do this with very little pedal manipulation. (Yes, he will burn thru. No big deal. This is about learning puddle control, and ya gotta break some eggs.......) He will be more able to add dabs and move, and use minimal pedal movements. The heat of the puddle will be controlled eventually by his movement speed, and the ability to dab, dab, dab, dabdabdabdabdabdab. In reality, these are the welds which are done quickly, are strong, not too bulky, and look pretty good so you will be confident in sending these out to a buying public. 10 out of 10..... reptition consistency is the key to this. And don't feel bad when it takes some more practice; I just tig welded on a bucket today because the guys running stingers were way too busy. SO, there I was at 200A WFO, throwing in 1/8" rod to fill a gap of over 1/4". No biggie, until you have to show that weld to 4 pipeline welders with 20+ years under the hood. And I quote " Yeah; another 10 sticks of rod and the holes will be closed. But how on earth are you gonna make it look good???????" I'll get even; tomorrow I will break out some .049 316 SS tube, and let them try to stick weld that up. And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Rojodiablo, thanks for the tips. He has a problem with slamming down the pedal to start. He tends to spend a good 5 to 10  seconds just slowly heating the metal up, which annoys me since it takes twice as long to weld and wastes gas.