Welding Aluminum - Questions/Tips

[Paul F]

Originally Posted by bobcowan

Do you need to use gas? What gas do you use?

I don't use gas with my MIG welder, but I can. I know on steel you get a cleaner weld, but so far I havn't wanted or needed to mess with gas.

Metal Inert Gas - that is MIG. By definition, MIG is a process that uses gas. If you are using a MIG welder without gas, you are using wire with flux in it and that is called arc welding. You are stick-welding with a MIG welder. It's just that the stick is now very small and is now a wire instead of a stick.

Gas is much cleaner as it has no flux getting around the weld.

If you are welding without gas or flux, you probably are experiencing really bad results.

[bobcowan]

I use a flux wire in my MIG welder. For my purposes, it works just fine. Is there some way to do that with alum? Like a flux alum wire?

[mickmate]

First time I welded aluminum I used an oxy acetylene torch and they had flux core wire available. Of course you can get a Borax type flux to coat your filler rod and the parent metal with. There looks to be a huge selection of flux cored MIG wire available these days. aluminum flux cored wire - Google Search

[LMH]

I've never heard of aluminum flux cored wire for MIG or wire-feed welders.
Larry

[lovehamr]

Just looking at the differences between my steel flux core welding and steel with gas, I'd have to think that my ally welds with flux core would really be ugly!

[trg-42]

Hi Larry, which Lincoln mig do you have...the 230volt family or 115 volt family ?

Do you have the aluminum feeding kit ( polish U groove, teflon liner, etc )

Two reasons why you are not able to achieve proper arc length

1. ensure you are on DC+ ( gun reciever to the +ve terminal )
2. ensure you are not having feeding issue ( lack of WFS will create situation you describe where arc length is excessive
Test this by letting wire feed into a gloved hand...does drive rolls slip
3. ensure your spindle brake tensions is almost backed off all the way

What alloy electrode are you using...two common choices are ER4043 and ER5356 . ER5356 will feed much better....less birds nesting but ER4043 will have more penetration for give wire feed speed

You want to use ER4043 for these small MIGs

Ditch the .030 and go with .035 . Trust me on this one

Key to GMAW of aluminum

Bring WFS up high enough to ensure you can achieve good wetting. Depending on your Lincoln model you will be at least 7 to 9 on WFS
Adjust the voltage to achieve the desired arc length

Your speed and technique sounds right ( high travel speed , slight ( up to 15deg ) push angle . less than 1/2" electrical stick out

[trg-42]

Originally Posted by LMH

I've never heard of aluminum flux cored wire for MIG or wire-feed welders.
Larry

There isn't . Generally speaking welding aluminum is only done with inert shielded processes such as GTAW ...gas tungsten arc welding ( TIG ) , GMAW - gas metal arc welding ( MIG ) , PAW ( Plasma Arc welding )

It is critical that there is no reactive component such as CO2. This is very different from mild steel , low alloy steel, stainless steels etc where it is actually desirable to have some reactive content (which is why 100 Ar is not a good choice for mild steel MIG )

Unlike carbon steels, stainless steels , low alloy steels etc that can be welded with all the above processes BUT also flux cored arc welding ( FCAW-SS....very common with wire feed welders or "MIG" machines ) , gas shielded flux cored ( FCAW-GS...very common in fabrication of ships, bridges etc ) , SMAW ( stick welding...shielded metal arc ), SAW ( submerged arc )

BTW - all these processes are arc welding processes. It is a common misconception that arc welding means stick welding

Welding Aluminum with non Inert Processes

SMAW - only commonly available stick for aluminum is E4043 alloy. Welds awful !

Oxy Fuel - works well for 1XXX and 3XXX series aluminum. 5XXX and 6XXX no recommended but works in pinch

[LMH]

Wow, lots of great info trg!
My Lincoln is a a 115V unit. I have (or rather, did have) it set up for aluminum with the sleeve. Originally, I had the knurled drive wheel on it but as it was pointed out to me, that's the wrong wheel. I have the correct wheel now.
I'll try it with the wire you described. What I have been using is the .030" wire.

Although I have the inner Teflon sleeve for aluminum, my welder is currently set up for welding steel as I have a couple projects for work to do. Switching it is a PITA, which is why I was thinking of going to a spool gun.

So when I get back to teaching myself, I'll try your suggestions and see how it goes. Thanks for the advice!
Larry

[Three Peaks]

Larry,
Is your 115V unit set up for a spool gun? Most of the 115V units I have looked at, including mine, don't have the electrical connections for the spool gun control for the welder unit.
You may need to go to a larger unit to get the spool gun compatibility. I've been looking at the 180/210 amp units partly for this reason.

However, I've used the aluminum wire in my 115V Miller 130 and it worked pretty well as long as I kept my hose pretty straight and everything was good and clean, including my tips.

Good luck with your practice, it takes a bit to learn the technique.....

Bob

[LMH]

Mine can be set up for it, though I don't know exactly what I'd have to do to it. It shows the "optional spool gun" in the owners manual and how to set it up. As with most things, I haven't read the manual yet.

Larry

[trg-42]

Originally Posted by LMH

Wow, lots of great info trg!
My Lincoln is a a 115V unit. I have (or rather, did have) it set up for aluminum with the sleeve. Originally, I had the knurled drive wheel on it but as it was pointed out to me, that's the wrong wheel. I have the correct wheel now.
I'll try it with the wire you described. What I have been using is the .030" wire.

Although I have the inner Teflon sleeve for aluminum, my welder is currently set up for welding steel as I have a couple projects for work to do. Switching it is a PITA, which is why I was thinking of going to a spool gun.

So when I get back to teaching myself, I'll try your suggestions and see how it goes. Thanks for the advice!
Larry

You must have a fairly new Lincoln machine ( Power Mig 140 ?? ) then if it has the capabilities for option Magnum 100SG spool gun. It is well worth the $150 - $200 that they want for it.

I have used every Lincoln / Miller / Binzel / CK etc spool gun and push pull gun for aluminum and the best way to sum it it with the 100SG gun is that it works far better than it should for the money you pay

Good luck !

[LMH]

Yes, it's a 140. It has a switch next to the spool with the regular handle on one position and the spool gun in the other. Thanks again!
Larry