Aluminium MIG welding

[bright-spark]

Good going there Luke your getting the hang of it there mate by the looks of things, Photos are a right pain to get right at times I found though by turning the flash off and putting a spot lamp over the item it works for me no expert though just like my welding LOL

 

[lovelectricity]

try taking by the light of an arc. lol. on a serious note is the polarity for ally the same as mild steel? ive never welded ally so have no advice but a few questions also ally with magnesium does it not burn?

 

[shenion]

Polarity is the same.

When I use 5356 wire that has magnesium in it it leaves a black mess as the mag burns Increasing th gas flow helps (pure argon or Ar/He for Al), but still get some black soot.

 

[lovelectricity]

oh no prob,
do you know why they put they mg in there if it burns during the arc?
hungry for knowledge
geth

 

[shenion]

The mg is there to match the alloy of the target metal. If I remember right, it increases the tensile strength. During the weld, a small amount of both the Al and Mg can vaporize and travel out of the shielding gas. There it will oxidize. Has no effect on th weld other than making a mess.

 

[lexi]

It`s interesting Luke. This is a little go I had.http://www.mig-welding.co.uk/forum/showthread.php?t=2515

Nice work on the Rover. Some good stuff on that site. I recognise a lot of the names from original LRE forum. Makes me feel like getting another Landy............Idon`t know if that`s good or bad!

Alex

 

[Luke]

Yup, LR4x4 spawned off the LRE forum when that went south. The other forum to spawn off LRE was LRAddicts, which is now in with Landrover Monthly.

Similar happened with LRO, producing LRboards, which i'm an administrator on.

The Rangie is getting there, more slowly now I'm back at uni.

 

[bright-spark]

Come and join in the fun Lexi.. Land Rovers are a bit like Marmite but with nuts..

 

[lovelectricity]

of course sorry me being stupid of course it cant 'burn' within the shield, didnt think that through before i asked it but once outside the gas yes. would account for the deposits mentioned and why turning up the gas helped. sorry fingers fast, think-tank slow and leaky.

 

[matt1978]

Hi Luke,

The smoke you are getting is probably because you are (Or should be)using a Magnesium based wire. Probably 5356 (5% Mg) Its this Mg which causes the smoke and the black soot on your weld. Although you won't completely eliminate this, you will dramitically reduce it if you go from a square torch angle to a much more leading angle. Hard to describe in words but imagine that you want to have the gas flowing infront of the areas your yet to weld.

You will get better feeding results, if you use whats called a (Comi Liner) which is Teflon or Carbon, until the bit which goes into the Swan neck, then there is a flexable brass almost spring type thing (Again not easy to explain) but this will aid the current transfer onto the wire, rather than just relying on the contact tip. Also stops the liner melting in the swan neck.

Also, if possible, carry the liner all the way thru the euro fitting until it sits just off the rollers, this is much better than trying to feed 0.8 mm Alu thru the brass capilary tube as is done when welding steel.

It would help if you could also do the same at the back of the rollers, where the Wire comes off and into the rollers, replace with the plastic liner instead of the steel which you have fitted now.

Good luck!

 

[matt1978]

Also, the 5356 wire, is much easier to feed, purely because it is a harder wire. It has a higher Ultimate tensile strength than the 4043 (5%) Silicon wire too.

Silicon based wires are also no use if you plan to Anodise any of the work afterwards.

 

[Woody.v8]

I did this a few years ago with a Clarke 190t and 0.8 wire,
Like what people have said the wire tension was backed right off so its almost spinning, max power and max wire also i found that a long arc about 1 1/2" and more gas helped.