Welding aluminium with Sip Migmate 130

[outlaw13]

Can any of you guys help with some advice on welding aluminium with a Sip Migmate 130. Aside from the wire snagging up when theres any kind of bend in the tube (followed the guide on here & still got problems snagging unless tubes are straight) I cant seem to get a proper bead of weld laid down. The metal has been prepd & when I start to weld the wire seems to burn back on itself & the weld is frosted looking. It looks similar to when you run out of shielding gas when welding mild steel. I am using a brand new bottle of Argon gas & have checked that the gas is coming through ok.
Any advice would be appreciated.

 

[Luke]

Turn the wire speed up a lot, and try again. I found that wire speeds had to be considerably higher than for m/s.

Mig-ing alumunium produces 'smut' which is aluminium oxide, it can black and/or grey/white, you'll need to clean it off with a wire brush (should be s/s and only used for aluminium)

 

[Wozzaaah]

I reckon you're on a hiding to nothing but:
What thickness aluminium and what power settings are you using?

 

[backpurge]

What thickness of ally are you trying to weld?
It is notoriously difficult if not impossible with small power output DIY type sets MIG due to the poor arc characteristics, in the majority of cases you are far better off using AC TIC

 

[Luke]

I reckon you're on a hiding to nothing but

I did think the same, but thought i'd try and be positive!

 

[Wozzaaah]

Hehe, I see no point in beating about the bush Luke!
As Backpurge has said, welding alu with small welders is nigh on impossible so no point getting people's hopes up.

 

[outlaw13]

Thanks for the input guys, the thickness of material is 2mm wall box section. I will try turning up the wire speed & I take it I need to have the welder set on full power to have any hope of welding at that thickness with the type of welder im using?
Cheers.

 

[Wozzaaah]

Pretty much, yes. Once you've got the weld pool established you'll have to go like the clappers to avoid blowing through too.
Watch the fumes too, it will be very smoky.

Just a thought, have you swapped the liner for a teflon one or are you still using the original plastic or a replacement steel one? If you aren't using a teflon one then you'll definitely struggle to get the soft wire feeding smoothly.
Also, another tip when mig welding alu is to use the next size contact tip up from the wire size you're using to reduce the resistance even more.
Good luck, let us know how you get on.

 

[outlaw13]

Cheers Woz, I'll give it a try & let you guys know how it went.

 

[runnach]

I can't see it being possible to produce a reasonable weld with the kit you have outlaw13. Other problem being material thickness, very difficult welding 2mm T.

Anyways, no harm in trying, what the other lads have said, as in tips/advice is spot on.
Btw, what wire you using and, what is gas flow rate set at?

Cheers...........