Aluminum got "sticky"

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Man am I having a bad welding week. Sheesh.120 amps, 1sec pre flow, 4sec post flow, 15cfh, Gas lens  #7, 1.5% 3/32 lan tungsten. My usual setup. Outside corner joint, was using 3/32 4043 filler to fill a little gap I had. Top plate is .100 and bottom plate is .125.Tacked it and started to weld. I've done this same weld hundreds of times and this rarely happens and I really want to try and figure out the cause of it. Welded the first inch was good, after that it started to get sticky. Looked at my gas lens and it all looked clear. Took a piece of scrap and it welded a bead perfectly! Back to this piece and same results. Turned the piece around and same sticky/crappy weld. Back to scrap piece, welds perfect. Frequency was 180, balance was 65% ENUpped the gas flow to 20cfh and welded the other side and it came out good (not great, but good)So upping the gas flow "fixed" the issue, but how is it I can do a 4" weld and all of a sudden it goes to crap. No breeze either. This happened to me a few times last semester in class in the welding booth too and I couldn't figure it out. Is it possible that maybe there was some turbulence somewhere when going through the gas lens?Pics of the crap below and pics of the other side after upping the flow. Attached ImagesTorchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:Contamination,  gassing off once the AL area starts coming up to heat.Worst thing to do, once contamination or whatever problem is noted--is to justsoldier on, instead of stopping.Air gaps on corner joints help cause this, since there's no shielding to the backside,plus with the gas flow swooping down thru the gap, some of it can come back upto mess with you.Raising the gas flow rate can exacerbate problems.Blackbird
Reply:So you are saying that once the part is heated the argon is not flowing how it should due to the part being heated?I tried to continue when it happened but it made me have to stop and dip again. So is this mainly an issue on outside corner joints? Should I have lowered the flow then if you say raising the gas can exacerbate the issue?Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:Originally Posted by GambleSo you are saying that once the part is heated the argon is not flowing how it should due to the part being heated?......No, what I said 'Contamination, gassing off once the AL area starts coming up to heat.' Additionally, If one's trying to add filler prior to seeing any wetting of the AL surface, the filler doesn't flow or puddle and things start looking crappy-quickly. This is basic AL tig 101. I tried to continue when it happened but it made me have to stop and dip again. So is this mainly an issue on outside corner joints? ......No-can be any joint, a gap on the joints, doesn't help on bit--inside/outside/tee joints, since the backside sees zip shielding. Doing tacks at least every inch or so helps for tight fit, distortion control, weld profile, etc. Should I have lowered the flow then if you say raising the gas can exacerbate the issue?
Reply:Few things for you. You may have contamination in the aluminum that is gassing out as it heats up. Turning your gas up may help but I have had very little luck ever using that trick. Grind the area back out and clean the gap as best you can. Try again. Also looking at your pic it looks like your sealing up your piece. This is the one that has bit me in the butt most often. The gas in your part builds up and is trying to blow back out of weld gap that you are trying to close. You can weld the entire part perfect but can't weld the last 1/2". There are a few ways to get past this if it is your problem. First make sure to clean the area that you are trying to weld so that you don't have that issue slowing you down. If you can drill a hole somewhere that won't make any issues to have a hole so the gas can get out of the part while you weld. If cant drill a hole take your time and finish it with spot welds. Make a spot and let it completely cool, do it again. Hope this helps
Reply:Let me get this straight. The weld goes bad after 4" of weld. Sounds like the same time as it may take a really long surge to diminish. Check your gas flow at the cup with a portable gas checker to see how long your surge is and if you have a constant/correct flow after the surge. Sometimes the flow is blocked with a crushed collet or worn collet body. The collet can push through the land inside the collet body and cause your backcap to cover up your gas port. Yeah something is whack when it runs good for the first 4 inches then goes wrong.Last edited by shovelon; 08-22-2013 at 11:07 AM.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:I just put in a new wedge collet too.  I took out the worng and twisted collet on there. Go figure. Gas lens setup probably has a few hours on it max. Never heard of the portable gas checker. Got a link? Can you define the surge?It was a square box (thicker side) and I tried it laying on the bench and sitting straight up held in a bench vice. So the other end wasn't blocking the argon from flowing anywhere. The length is 4" so it probably went bad after 2 inches.Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:http://www.arc-zone.com/index.php?ma...oducts_id=7909I use mine a lot. I believe Terry is referring to the surge of gas when flow is started. Different regulators have different step down pressures. Most single flowmeters (and the nice Victor dual flow) step down to 25-30 psi. So when the flow stops, the line gets charged to this pressure. My cheaper Smith dual flow steps down to 50 psi, so I get a pretty strong initial flow of gas when I kick the pedal. That's why I kick the pedal, let the post flow run until things settle down, and then start my arc.
Reply:Right now I'm using the victor regulator that came with the 186. Did the same welds tonight and same results. Nowhere near as bad, maybe because I had it closer to 20cfh. I did take out the new wedge collet and go back to the old collet and the only time this happened was on the corners when tacking, but I'm sure I didn't wait for it to get hot enough. So maybe it's the collet. I can do some more back to back testing when I get more time.Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:Originally Posted by GambleI just put in a new wedge collet too.  I took out the worng and twisted collet on there. Go figure. Gas lens setup probably has a few hours on it max. Never heard of the portable gas checker. Got a link? Can you define the surge?It was a square box (thicker side) and I tried it laying on the bench and sitting straight up held in a bench vice. So the other end wasn't blocking the argon from flowing anywhere. The length is 4" so it probably went bad after 2 inches.
Reply:Figured that one out. Restriction in the gas hose which is strange because it's been working great for months.  Took off the crappy victor regulator and switched to a flowmeter and found out I couldn't raise the pressure very high.+1 for flowmeters over regulators.Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:Originally Posted by GambleFigured that one out. Restriction in the gas hose which is strange because it's been working great for months.  Took off the crappy victor regulator and switched to a flowmeter and found out I couldn't raise the pressure very high.+1 for flowmeters over regulators.
Reply:Originally Posted by shovelonThe one pictured is an ESAB unit($42)           http://www.amazon.com/Esab-19043-Meter/dp/B004HRAWGEI get mine cheaper ($29) from Netwelding.comThey are the same as the ESAB units.  http://netwelding.com/prod02.htm