tips for welding aluminum

[longviewlawncare]

I am getting ready to do some welding on aluminum. what is the best type of rod to use, heat setting, etc. I am using 1/8-3/4" angle. Never dine anything with aluminum before. Any help would be appreiacted. Thanks

[chip hayden]

what process are you using? smaw [stick],gtaw[tig], gmaw[mig].

[longviewlawncare]

smaw(stick)

[chip hayden]

i don't know how happy you'll be with the results.optimum thickness with al. coated electrode is @ 3/8-1/2" thick. even then the results aren't that impressive. if it's just a non-critical weld and appearance isn't an issue it will work.
here's a few suggestions.
1. make sure the rod is NEW and from an UNOPENED package. the fluoride coating on the rod absorbs moisture at a fantastic rate. this causes unstable arc characteristics and very ropy welds with lots of spatter.
2. amperage and postion is critical with this stuff. a few amps up or down makes a big difference. try to make all welds in a flat position to slightly downhill. this will also help with the thin metal you are welding.
3. use a backup bar as much as possible. you're going to need a heat sink of some sort to prevent burning thru. clean steel will suffice. carbon blocks, copper, or aluminum are a little better.
4. be patient and practice. coated al. electrodes have never worked that well, even from the maintenance rod companies like eutectic, certanium and others.
regards, chip.