welding aluminum advice

any advice on welding thin (16-14ga)aluminum would be greatly appreciated. im using a millermatic 210 with a spoolgun. i can weld thicker (10ga+) aluminum fine, but im having a problem layin a nice bead on thinner stuff. any tips like angle of gun, push or pull, downhill or horizontal, or any thing else? thanks in advance

are you burning through? what do the beads look like?

might need to try and stitch weld it.

yes, burning through, and if i go faster its not a nice smooth uniform bead. i have the welder set up like it says in the chart. ive never welded this thin of aluminum before, so i'll prolly get the hang of it with practice, i just thought some advice could speed up my progress.

Part fitment is critical with thinner material the fitment of the pieces has to be perfect. I build alot of aluminum fuel cells and I make sure they are tight on all the gaps or I build another piece.

I use a tig though, never used a spool gun.

I have the same setup. I havent realy messed with it yet. I've only had it about a month. I was told by a guy who welds aluminum tanker trucks, that with the gun you have to stitch weld it. He said just start, stop, start, stop. He also told me to push the gun, not pull. Like I said I havent tried it yet so it's not tried and true. I was worried about it sealing using this method but he told me that aluminum seals alot better than steel and that I shouldn't have a problem. Just my .02

Edited: 11/27/2006 8:04:41 PM by roadfool

hmm i never stiched it when i tried it on 1/8th inch but it was thicker. maybe try messing with the settings, i know it would be different then the manufactuers recomendations but maybe it just needs a little tweaking. good luck bro. i find aluminum the hardest thing to weld. i remember when i was learning tig aluminum it would bubble up on the back side, is this what it is doing or actually blowing through?

try turning the heat down

Welding thinner aluminum is just a bitch with a MIG, TIG would make it much easier. However though the stitch technique would probably work best if you don't have pulse on your welder. Pulse welding switches back and forth between a peak current and a background current so the puddle basically goes from liquid to solid very quickly and it keeps the metal cooler so you get a better bead. Another thing to make sure you do is double back at the end of your weld with aluminum, if you don't it has a potential to crack in the crater from where you finish the bed.