I have a question about gmaw of alluminum. would I be correct in saying that all gmaw of allum. is or should be done in a spray transfer, or in pulsed mode rather than short circuiting? We have an older spool gun at my shop that works great when welding 3/16 or 1/4 in. allum. of the 3000 series. With these thicknesses I can turn it up and spray very nice. The problem is when welding thinner mat. ( .063 to .125 ) short circuiting is very ugly and spray trans. is to hot. Pulse is not available. Therefore I am limited to tigging all lighter material. We use 4043 filler (.047?) in the spool gun.
My boss is considering buying a new multi-process power source and attachments , whether it be a push-pull gun or a spool gun, to weld allum. yet still able to weld mild steele and stainless. This machine must have pulse capabilities. Any good idieas on what we should be looking at would be greatly appreciated. Any info on above question would be equally appreciated. Thank you very much!
to put it as plainly as possible....aluminum needs to be welded hot and fast. Aluminum cannot be effectively welded in the short circuit mode and still achieve sufficient penetration. thinner material is best welded with either a constant power mode (referencing the power mig 300 from lincoln.) or double pulse. the other option is of course tig welding.
I am sure you are going to get a few different ideas on this, but as always....this is my 2 cents worth.
Mike,
You might save your boss a bundle by inviting your local Cobramatic rep in to demonstrate his gun on YOUR current mig power source. Its just possible that a quality after market Item such as that is the way to go.
Buying a pulsed mig powersource costs almost as much as two conventional mig machines. Mind you aluminum is one of the few places where Pulsed powersource owners actually can switch the pulser to the "ON" position and make money. Its worth checking the alternatives.
I once worked in a shop with the same equipment limitations. When we had to weld light gauge aluminum, we switched from 4043 to 4047, which has a lower melting temperature. We were mostly concerned with the cosmetics of the welds though, no structural considerations. You might try a roll of it for a cheap fix, the 4047 wets in real nice on gmaw short circuit. But if your boss wants to buy new equipment, let him!
drop down to .035 or even .030, 4043 these will spray and weld down to 1/8
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