Please help - how do you preheat aluminum for mig ?????

[Stu Miles]

Would like some advice on preheating aluminum bar.
Tack welding 1/4 inch aluminum bar for tack weld at T joint.
How would I preheat for mig welding with a passport plus using spool gun
an argon.

Anyone have experience welding aluminum bar with mig ?

[pressurewelder]

That thin you really don't need a preheat just turn it up and go.

[aametalmaster]

Anyone have experience welding aluminum bar with mig ?

35 years worth. I use a propane torch...Bob

[Stu Miles]

Hi Bob
I guess I should have asked first -
Do I need to preheat the 1/4 inch aluminum bar ?
using passportplus/spoolgun/110.
I've been told it's not possible as it will be too cold,
then told it would melt too fast.

Thanks for reply,
Stu

[aametalmaster]

Don't know about your passport as i have never used one but you will just have to try a couple of small chunks of what you will be doing. That would be the best way. Just my thoughts...Bob

[Country Metals]

Even with heat, you are pushing the passport at 110. It all depends on how practice pieces work out.

[Portable Welder]

I had to weld 7" x 7" x 8' chunks of aluminum to 4x4x1/4" TS and used a propane rose bud and a temp stick, I brought it up to 450 degrees before welding it with my push pull set up.

[FusionKing]

Try a test piece first. If the bead profile is too high, then preheat and try it.
Some things need preheat just to get the bead to flow out decent.
I like to use the AO torch and smoke it (with the soot) myself. Then heat until smoke is gone. Works good for me.

[goatram]

Mapp gas burns hotter. Costs more but works better.

[cabininthewoods]

Make sure if you are preheating or welding to insulate it, if you are welding on a steel table, the steel really sucks the heat out of aluminum and makes it difficult to weld