Ugly Aluminum

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I tried to stick .060 aluminum square tubing together tonight and got these results.  Not horrible bead on flat aluminum, but at the joints, the edges seem to just melt away.  I also noticed I have almost no etched cleaning zone with my Synchro on a balance setting of 5.  Fillet welds were even impossible for me.1/16 Tungsten75 ampshood time around 8 hoursTA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:What size filler wire are you using? Anything larger than .0625 on your thin tubing will create problems. Larger filler acts as heat sink when introduced to puddle. That would also explain the joint weld problems. The heat required to melt filler exceeds temps need for base, washes out edges before filler puddles.Miller TrailBlazer 251Miller HF-250-1Miller MaxStar 150 STLHyperTherm PowerMax 380 plasmaLincoln PowerMig 180Millermatic 252Miller Diversion 180
Reply:Start a puddle on one piece, hit it with filler, then move to the other side, get a puddle, hit it with filler and now the two will be more likely to bridge the gap. Don't break your arc, just direct it onto the two work peices. Watch your torch angle as well, keep it vertical for tacking, it will focus the heat right where you want it.To me, it looks like you are trying to get a puddle going on both sides before you fill and overheating the workpiece, causing it to fall apart. The above technique is what I use for thin stuff. AL has a tendancy to shink up on the edge when you get a puddle, adding filler will lessing the shinking effect. Once you get the two puddles built up, it's a matter of getting them molten again, then dab between them. Sometimes the two just fuse when you start to work both puddles.
Reply:I believe you are both right.  I used both 1/16 and 1/8 filler on the pieces.  I only had 5356 in 1/16, it seemed to flow less than the 4043 did.  I certainly did try to light up on the joint, not as you said to do.  That is when the melting away occurred.And the OP should have read "fillet welds even MORE impossible for me".  You guys make this stuff look easy.Last edited by Drf255; 10-23-2011 at 05:20 AM.TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:For the groove weld, get puddles going on each side and use the filler to start to join the gap then BACK OFF on the heat and continue with just enough heat to keep a puddle.  It gets tricky.Aluminum goes pretty fast once you start, so if you dilly dally it all ends up in a puddle on the floor.Two aluminum puddles will not join them selves.  Use the filler to get them to jump together.  DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:I have exactly the same problem as OP but too embarrassed to post pics. Just a bead on flat aluminium is OK but trying to join two pieces together...yuck.I thought I had a gas problem at first but your answers explain the reasons perfectly.__________________________________________________  _I could not care less where anything is made. I don't fall for the myth that locally made is 'better'. If I think something is good value for ME, I'll buy it. That said, I do like European quality
Reply:Are the edges of your aluminium clean? Also try and set it up so that there is something behind the joint to keep the argon there - shielding is really hard around the corners of small stock, so try and trap it if possible. If the joint is clean and is shielded then the weld pool will flow down the edges. You need to increase your cleaning action (i.e. +ve component) in your AC balance just a fraction. If you don't get these 3 things right, then the edges will always try and melt back away from each other as you add more and more heat to try and get the weld metal flowing.Personally I light up right on the butt joint and move back and forth across the join until the cathodic etching has done its work - when both sides are shiny then I dab the filler right in the middle and it will wet out to both sides and flow into the joint. It helps to practice with lower amps - so it might actually take a whole second or more before you can start the bead proper.Having said that - some of your beads on the flat metal are too cold given the size of filler. 4043 is a bit more forgiving as it 'wets' nicer, but 5356 will work just fine.Fillet welds are a pain - with thin aluminium I use a nice sharp tungsten (at low amps the lathanated ones will hold the point) and get a nice tight arc in close to the corner. Good fit up helps immensely in this case.- MickLast edited by weldermick; 10-27-2011 at 06:58 AM.
Reply:The funny thing is that the three beads ou see laid out next to each other are with my machine set at AC balance of 8, 7, and 5.  8 is at the top.  The more cleaning, the less penetration.  The bead at the bottom didnt even imprint the opposite side of the tubing.TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:Originally Posted by Drf255The more cleaning, the less penetration.  The bead at the bottom didnt even imprint the opposite side of the tubing.
Reply:I forgot to mention - for the fillet welds on aluminium, if your welder has AC frequency adjustment, it helps to have a high frequency going, which will have the effect of narrowing the cone of the arc - which will help to concentrate the heat of the arc right down in the fillet.