Help! my TIG thinks it Rambo

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It's blowing holes in everything I try to weld with a vengence. I've been practing butt welds on .055 T3 aluminum coupons all day and its killing me. I end up just melting the edge's away before I can get a puddle started. I started out just doing straight runs which was easy. I even did some steel sheet metal with no problems.I'm using the Miller synco 200, it set on AC, 100% Argon. I've adj. the amps from 90-150 and used the balance control. Now my Tungsten is 1/8" which is what came with the welder. Is that too big for what I'm welding?  shoud I change my cup size also? Shoud I be using the balance feature? and at what %?I've been grinding the tip to a point and then putting a flat on the end, or should I be using a balled end for AL?Last edited by gixrman; 01-16-2007 at 05:56 PM.
Reply:.055?Man..I'd have a 1/16 tungestion in there sharp! end...small cup..80 amps MAX..but thats just me.....zap!Last edited by zapster; 01-16-2007 at 06:23 PM.I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Are you saying you put a sharp point on your Tungsten?
Reply:So do I understand, when you say you "started out just doing straight runs which was easy", does that mean that running beads on the surface of the sheet was easy, but now when you try to join two pieces along a butt joint you "end up just melting the edge's away before I can get a puddle started"?If this is the case, where the butting edges don't want to wet together and coalesce into a single pool, there are a few things to think about.1.  Pre-weld cleaning:  Degrease with acetone the wire brush with clean stainless steel wire brush.  Butting edges may be filled with a clean file.  Aluminum oxide will prevent the melted edges from wetting together.2.  Joint fit-up:  Square butt edges, no chamfers on edges, butted tight with no gaps.  Surface tension tends to draw the melted edges away from each other, the pool wants to ball up, a gap makes it worse, and filler has to be dabbed in to help bridge the gap or join the separate melted edges.3.  Tack weld:  Get the tungsten in close, centered on the joint line at the end of the sheets, hit is hard and fast, dab a bit of filler as the melting begins, get in there, get it done, get out. You need to concentrate the heat, and get in there and heat it fast.  If you start out at low amps, and take you time about it, the heat spreads so rapidly that soon a large portion of the sheet is too hot and surface tension sucks it up into a ball on both sides of the joint.  So, in other words, Zap it!4.  AC balance, try more DC electrode positive% (DC reverse polarity) for more arc cleaning action.  The aluminum oxide opposes the wetting of the two pieces together.I think a 3/32" or 1/8" tungsten ground to a taper with a small flat is ok.As for gas cup size, and I'll add, flow rate, these should be negligible factors.  I mean the idea is to shield the weld and surrounding hot metal from oxidation, so a relatively large gas lens with moderate flow would be great.  A small nozzle or higher flow rates could lead to turbulence and air contamination.
Reply:Yes, when I ran beads on top I was able to get nice shinny puddles and practiced adding filler. When I attempted to do butt-joints is when I ran into problems and it snow balled from there. I was just wire brushing the joints and they were'nt perfectly square. I'll try the acetone tomarrow. Is this why when I first start the arc that it seems to jump all over the place? This happened more so when I tried doing t-joints. I can see it burn though the oxidation when I first start, the pitch (sound) of the arc changes and it seems to concentrate.
Reply:For what it's worth, with aluminum (for me anyway) butt joints never, or almost never, flow together on their own. I usually see 2 shiny areas moving apart from each other as the ends begin to melt away, then I jab some filler in to melt and bridge the gap.Keep at it, it'll click all of a sudden and you'll 'become one' with the plastic, molten aluminum, grasshopper.- John
Reply:ThanksI think half my problem is my material selection.
Reply:You might also try propping the pieces together in an inverted 'V', then weld the seam along the top. I think that's a little bit easier than a butt joint.This stuff all kicked my butt the first few times.- John
Reply:be sure to choose a stainless steel wire brush for cleaning aluminum.DennisThermal Arc 185-TSWMillermatic Challenger 172VictorO/AAtlas Craftsman 12 by 24 LatheEsab PCM-875Wholesalem Tool Mill-Drill
Reply:Just wanted to say thanks guys. I cleaned everything up like you stated turned the amps down to 70 and started laying some nice beads. I still need some more practice before i start welding up my intercooler pipes and another bottle of Argon.Your right runchman, the gap does'nt need to be much for the puddle to start walking away.Last edited by gixrman; 01-20-2007 at 09:20 PM.