Aluminum Question

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Been practicing my aluminum skills ever since I got the Airco in my sig and so far so good, I'm learning, but today I ran into something I hadn't seen before. I finally got the 100A breaker for my welder so I was finally able to crank it up a bit and weld something thicker. I grabbed a piece of 1/4" scrap aluminum, cleaned it with a SS brush, wiped it down with acetone, repeated, wiped off a few filler rods, cranked the welder to 255A on AC and sat down at my chair. I lit up on the piece of aluminum, let the cleaning action go for a few seconds, then laid into the pedal, as the amperage came up and the puddle formed it practically exploded in my face, the puddle was churning and very violent, the whole piece of metal was vibrating, and upon adding filler droplets of molten aluminum went flying everywhere. I'm just curious as to what the hell happened. I've never welded any aluminum above 180A until today(the puddle was always silky smooth). Tungsten held up perfectly fine. Was I maybe staying in one place to long and letting the puddle get too deep/wide? I tried again and laid a bead about 1" long and every dip metal blew out of the puddle, and after lifting my hood the bead was almost 1/2" wide and really funny looking.Settings are as follows:1/8" Thoriated Tungsten. Blunted taper.255A AC. Continuous HF.20 CFH Argon#8 Standard CupBalance on my machine is locked at 50/50 and is Sine-Wave only.Brad GeorgeCurrent Equipment:AIRCO Heliwelder IV 300Amp Model - Total Awesomeness!Old 120v Hobart Handler MIGVarious grinders, cutting tools, hammers, clamps, ect..."I'm an amateur welder with lots left to learn..."
Reply:The puddle may do that until it reaches a saturation temperature to attract the filler. If the metal is cold the puddle will not settle into a bead.Adding helium helps speed up the heating  process. Try it again and ease into it gently and slowly until there is enough heat in the base.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:Too much amperage. I can squeeze 1/4 out of my 180 syncro. Feather that pedal. I hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:Thanks. I'll see what I can come up with here...Brad GeorgeCurrent Equipment:AIRCO Heliwelder IV 300Amp Model - Total Awesomeness!Old 120v Hobart Handler MIGVarious grinders, cutting tools, hammers, clamps, ect..."I'm an amateur welder with lots left to learn..."
Reply:I thought I have always read that some people say on aluminum to go full pedal and back off. I take it this isn't the case?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 thought I have always read that some people say on aluminum to go full pedal and back off. I take it this isn't the case?
Reply:I agree with weldermike and shovelon on this one. Light up at a low amperage and let the arc clean for a short time, slowly add some pedal until the surface starts to get 'sweaty' looking, add a bit more pedal and start feeding filler.
Reply:Gamble --------------------------------------------------------------------------------"I thought I have always read that some people say on aluminum to go full pedal and back off. I take it this isn't the case?"  "Not for me bud, I never do that or understood why people say that, thats just me tho. I like to judge my takeoff on what the base metal is doing, so I feather and pedal it till its perfect, then move on."  - WelderMikeWelderMike:  I think the reason you are able to weld 1/4" aluminum with your 180 amp unit is because you are actually preheating the piece using your slow and gradual approach to aluminum welding.  If you hit the pedal hard like most of us do to start an aluminum weld, and tried to weld 1/4" aluminum with the 180, I doubt you would get a very good puddle. (until the piece soaked up enough amperage to heat the part).Miller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma
Reply:Originally Posted by DougAustinTXGamble --------------------------------------------------------------------------------"I thought I have always read that some people say on aluminum to go full pedal and back off. I take it this isn't the case?"  "Not for me bud, I never do that or understood why people say that, thats just me tho. I like to judge my takeoff on what the base metal is doing, so I feather and pedal it till its perfect, then move on."  - WelderMikeWelderMike:  I think the reason you are able to weld 1/4" aluminum with your 180 amp unit is because you are actually preheating the piece using your slow and gradual approach to aluminum welding.  If you hit the pedal hard like most of us do to start an aluminum weld, and tried to weld 1/4" aluminum with the 180, I doubt you would get a very good puddle. (until the piece soaked up enough amperage to heat the part).
Reply:Originally Posted by weldermikeY What i'm getting at is whats the rush, you just can't weld fast, and if you do what did you really save, 3 seconds.
Reply:I'm no hobbyist, and I have work all over the place and nothing comes back to me. I understand your physics behind it Doug, but i'll go toe to toe and pay the shipping if someone wants to do some destructive testing. I guarantee the results would be minimal if that in most situations. Fill heat and tie ins go a long way.  Wanna do it! I'm game!I hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:Set the machine to the correct amperage, and then move up to full pedal. But not fast enuff to blow a hole thru itThat feel just comes with experience.I also agree with DSW, altho I have had to "make do" with less. Sometimes it takes years before you know what really works and what doesn't. As I improve constantly, I look at my old work, and can spot many things I have changed my thinking on. Wasn't bad then really. Just better now.Older transformers are more sensitive to tungsten size than square wave machines. When the puddle goes all wonkey a bigger tungsten tends to help.  Pure sine is just different.Miller Dynasty 700Miller 350P with Aluma-pro push-pullMiller 280 Dynasty with expansion card Dynasty 200 DXMigMax 215 Enuff power and hand tools to create one of anything..... but mass produce nothing!!!
Reply:It never blew through the back of the plate, the puddle was exploding towards the torch and the molten puddle was churning very violently. I think I could also use some bigger filler metal as well, all I had on hand was 3/32" 4043.Brad GeorgeCurrent Equipment:AIRCO Heliwelder IV 300Amp Model - Total Awesomeness!Old 120v Hobart Handler MIGVarious grinders, cutting tools, hammers, clamps, ect..."I'm an amateur welder with lots left to learn..."
Reply:Originally Posted by blasphemy000It never blew through the back of the plate, the puddle was exploding towards the torch and the molten puddle was churning very violently. I think I could also use some bigger filler metal as well, all I had on hand was 3/32" 4043.
Reply:Pictures would help greatly.You could also see if the gas is blocked at the torch. Sometimes the collets get twisted or flared blocking the flow of gas even if it says the correct amount is exiting the flowmeter.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:Originally Posted by Donoharmthe tungsten exploded not the puddle .lantahanted 3/32 can handle 225(maybe a bit more) amps if you ball it up before you go crazy with the amps .
Reply:Originally Posted by shovelonPictures would help greatly.You could also see if the gas is blocked at the torch. Sometimes the collets get twisted or flared blocking the flow of gas even if it says the correct amount is exiting the flowmeter.
Reply:The test beads I was running was on regular aluminum, but this is what I was actually trying to weld(cast). Here are two pictures of it so far. I still have some smoothing and blending to do but I can't find my sanding drums for in the air tools. The combustion chamber was originally completely round where as now it is heart-shaped. This should improve combustion and if nothing else it will raise the compression along with what will be milled off the head. This is off of a Honda GX390 13HP engine that is going on a go-kart.Edit: Damn. Forgot pictures of the torch...Brad GeorgeCurrent Equipment:AIRCO Heliwelder IV 300Amp Model - Total Awesomeness!Old 120v Hobart Handler MIGVarious grinders, cutting tools, hammers, clamps, ect..."I'm an amateur welder with lots left to learn..."
Reply:This is my "weird" torch as I call it. The threaded brass part where the cup screws on. On the face of that there are 6 small holes pointing towards the tip of the electrode.Brad GeorgeCurrent Equipment:AIRCO Heliwelder IV 300Amp Model - Total Awesomeness!Old 120v Hobart Handler MIGVarious grinders, cutting tools, hammers, clamps, ect..."I'm an amateur welder with lots left to learn..."
Reply:Finally got a chance to post a little. Just showing that you can make an under powered machine work for you with a little manipulating. 1/4 plate, 180 amps, not even hittin it full throttle, 3/32 pure tung. Attached ImagesI hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:The only reason you are able to weld that plate with 180 amps is because it get's heat soaked and finally allows a puddle to form. If that were part of a larger weldment and had no pre heat, it would be nearly impossible with that welder and argon to get a weld. Might be possible with a He/Ar mix, but not straight argon.
Reply:Originally Posted by BCTimberwolfThe only reason you are able to weld that plate with 180 amps is because it get's heat soaked and finally allows a puddle to form. If that were part of a larger weldment and had no pre heat, it would be nearly impossible with that welder and argon to get a weld. Might be possible with a He/Ar mix, but not straight argon.
Reply:A little bevel would have went a long way, but didn't do it purposely to show i'm not tryin to pull a rabbit out of a hat, but it can be done! 1/4 on 1/4, and still did'nt mash it with 180amps. Too lazy too change collets and tungsten. Whooped and sippin!  Attached ImagesI hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:Originally Posted by blasphemy000The test beads I was running was on regular aluminum, but this is what I was actually trying to weld(cast). Here are two pictures of it so far. I still have some smoothing and blending to do but I can't find my sanding drums for in the air tools. The combustion chamber was originally completely round where as now it is heart-shaped. This should improve combustion and if nothing else it will raise the compression along with what will be milled off the head. This is off of a Honda GX390 13HP engine that is going on Edit: Damn. Forgot pictures of the torch...
Reply:Originally Posted by Drf255does the piston head contour match the mod you did to the chamber?Getting back to your problem, cylinder heads weld dirtier than most any alum.The heat is just not getting into the base metal fast enough, and dirt is burning off from the surface at the same time. This is just a normal occurance for what you are doing.I work in a complex adjacent to an auto machine shop, and he preheats heads to 400 degrees F. before he walks them over. They weld nice. If he just has a corner or divot to fill, no preheat, but they weld just like you describe. I have to ease into the arc or the surface will crud up. So I have to back off the pedal, let the arc clean the crud, and gently add filler until enough heat has saturated the weld zone.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:Thanks for the tips. I know I should have preheated but I didn't figure my mother-in-law would have appreciated me heating a head in her oven.Brad GeorgeCurrent Equipment:AIRCO Heliwelder IV 300Amp Model - Total Awesomeness!Old 120v Hobart Handler MIGVarious grinders, cutting tools, hammers, clamps, ect..."I'm an amateur welder with lots left to learn..."