Aluminum welding requirements

[Columbo]

It depends on the thickness of the wire and the particular machine. A spool gun is typically a more trouble free MIG solution. There are also push-pull systems where in addition to the push drive rollers in the unit, there are pull drive rollers in the gun. The big problem is that aluminum wire is soft, so it can bind up easier, and the drive rollers can't grip it as well as steel.

For SMAW you can use E4043 electrodes, but be prepared for a little sticker shock. Standard E7018 rods are around $2.90 a pound while E4043 from the same source is $33.24 a pound.

WOW! The reason I was asking about the aluminum weld is that I am an amateur radio operator, (HAM), and I like making antennas which, of course, are made from aluminum tubing and square aluminum booms. I can buy a 7 foot x 2 inch square aluminum boom for that price so what makes these rods so expensive?

[undercut]

WOW! The reason I was asking about the aluminum weld is that I am an amateur radio operator, (HAM), and I like making antennas which, of course, are made from aluminum tubing and square aluminum booms. I can buy a 7 foot x 2 inch square aluminum boom for that price so what makes these rods so expensive?

Unfortunately, probably because of the low demand and maybe because of the exotic flux composition on the aluminum. People doing a lot of aluminum will usually opt for MIG or AC TIG so these rods aren't in high demand. SMAW aluminum (from what I've read) doesn't always result in very good welds either. With a TIG setup on your PA200, you could weld with a helium shielding gas but I doubt you have a helium tank just hanging around.

[Rambozo]

Maybe the flux is made by psychotic elves that mine the magic smoke from microprocessors? Or maybe not.

[Columbo]

Unfortunately, probably because of the low demand and maybe because of the exotic flux composition on the aluminum. People doing a lot of aluminum will usually opt for MIG or AC TIG so these rods aren't in high demand. SMAW aluminum (from what I've read) doesn't always result in very good welds either. With a TIG setup on your PA200, you could weld with a helium shielding gas but I doubt you have a helium tank just hanging around.

Your right,... I don't have a helium tank,... or an argon bottle,... or the optional TIG kit. I may look at getting those items in the future but for now I need to practice with the PA200 with the stick. Once I get the hang of that, then I'll try venturing further and try the TIG thing.

[Shield Arc]

I did a little playing around with it a few months ago. You gotta move fast! And keep the proper arc length. It is almost like spraying it on. I'll take Tig, then Mig over SMAW of aluminum anyday.

[blacksmith]

One thing I've never understood, why is a DC machine unable to weld Aluminum and a DC machine with a Spool Gun can?

[performance]

Good but complex question to ask and answer.

But here is the short, abbreviated version.

1) AC is a combination of DC+ and DC-. DC+ cleans the oxidation from the aluminum while offering very shallow penetration. DC- gives the penetration but offers no cleaning action
2) TIG uses a non consumable (but really it is a consumable) tungsten that is able to withstand the high heat of DC+. Because when the polarity shifts to DC+ the majority of the heat is placed on the tungsten because the electrons are flowing from the workpiece to the singular point of the tungsten. You can weld Aluminum in DC+ with TIG, theoretically, but if you were welding at say 200 amps, you'd need a tungsten half as thick as your forearm because it would want to melt other wise. (not quite but in comparison to regular AC or DC-)
3) MIG is a different process and it is done in DC positive. The wire is constantly consumed, which is ok, and because it is in DC + cleaning action occurs. But because aluminum is welded in MIG in the spray mode only, the metal is transferred across the arc and into the molten weld puddle. Since the wire is the electrode, and is constantly consumed, the heat generated isn't an issue.

[blacksmith]

Ok, so the spool gun is just to sidestep the handling of the consumable and its tenancy to kink in the liner. Nothing magic about the gun, and the weld would look the same whether from the spool or the mig gun.