Ali Welding with Mig

[Z()LTAN]

Hey fellas, ive started welding ali with my mig.

Alls going sweet, i spent the dosh and got all the ali parts for the gun and the ali "u" groove roller. So its feeding sweet.

My issue is wire/voltage settings.

Im welding 3mm to 3mm and 10/6mm to 3mm.

So far i have the welds going down fairly well but they seem to burn almost 100% to the other side (butt join with 1mm gap). Id like to get a decent more ropey weld if i can.

I have been told to have the welder cranked and push the weld pool is this correct?

Its a 250A Lincolin welder.

Cheers guys

[Z()LTAN]

Update,

Im welding with .9 wire.

Welder has 1-3 course amp steps and 1-9 fine amp steps.

I was using 2/8, now i tried 2/1 and its alot better.

I usually use 2/5 or 3/2 for mild steel.

Thoughts?

[nastytroll]

Usually a standard mig will have the wire feed ramp up slowed down to get the ally hot at the start of the weld. Typically a standard mig will start the weld cold and finish too hot.

If you have oxy/acet, run the accet flame (no oxy) and soot the ally up. Change to a neutral flame and warm the ally around the welded area til the soot burns off, this will get you the right pre-heat for welding.

Pre-heat it usually only used on thicker sections, but as you are using a standard mig it will help get the ally to weld temp and help with avoiding cold lap.

If its for your intercooler or something to be water/air tight, you may need to get the start of the weld gone over with a tig to get it sealed. Standard migs are not good for sealing ally as they start cold.

The slowed ramp up helps with getting the weld pool up to temp but when changing back to steel/stainless it will need to be sped back up again or the wire will burn back to the tip. Most fabbies will get an external POT fitted so the ramp up can be adjusted with out going inside to the circuit board.

Also you should be running the ally at higher amps then steel and with a much higher wire feed from my experience. I'm not a fabby so I'm sure someone else can give better info then me.

[Slunnie]

Most fabbies will get an external POT fitted so the ramp up can be adjusted with out going inside to the circuit board.

I'm not sure about other MIG's, but we bought an Air Liquide (SAF) to do ally - mind you its only ever done steel, but it has all of the soft start ramping etc already on the machine. I would have assumed that most other Ally MIGs would already have these pots in place???

[nastytroll]

Most fabbies will get an external POT fitted so the ramp up can be adjusted with out going inside to the circuit board.

I'm not sure about other MIG's, but we bought an Air Liquide (SAF) to do ally - mind you its only ever done steel, but it has all of the soft start ramping etc already on the machine. I would have assumed that most other Ally MIGs would already have these pots in place???

By ally mig are you talking pulse mig? Some migs do have a ramp up feature, most I have used do not as its attached to the wire feed rate. Pulse mig is the best for migging ally but are very expensive.

[Slunnie]

Most fabbies will get an external POT fitted so the ramp up can be adjusted with out going inside to the circuit board.

I'm not sure about other MIG's, but we bought an Air Liquide (SAF) to do ally - mind you its only ever done steel, but it has all of the soft start ramping etc already on the machine. I would have assumed that most other Ally MIGs would already have these pots in place???

By ally mig are you talking pulse mig? Some migs do have a ramp up feature, most I have used do not as its attached to the wire feed rate. Pulse mig is the best for migging ally but are very expensive.

I wish we had a pulse MIG.

No, the machine starts with a slow wirefeed and then ramps up to the set speed with ally wire.

[awill4x4]

Personally I wouldn't recommend 0.9mm wire, I would up the size to 1.2mm. It allows you to up the amperage while using the larger wire to "cool" the weld pool and introduces a bit more flexibility to what your trying to achieve.
You don't state what grade of wire but I'd recommend 5356 over 4043 as it's a bit stiffer and less likely to have feed problems, particularly if you have a long lead for your Mig Gun.
Make sure you run a teflon liner for Aluminium also, you're less likely to end up with shavings clogging up the liner.
Regards Andrew.

[nastytroll]

Personally I wouldn't recommend 0.9mm wire, I would up the size to 1.2mm. It allows you to up the amperage while using the larger wire to "cool" the weld pool and introduces a bit more flexibility to what your trying to achieve.
You don't state what grade of wire but I'd recommend 5356 over 4043 as it's a bit stiffer and less likely to have feed problems, particularly if you have a long lead for your Mig Gun.
Make sure you run a teflon liner for Aluminium also, you're less likely to end up with shavings clogging up the liner.
Regards Andrew.

Yeh, I forgot to mention the liner.

[Z()LTAN]

Yeah i got the teflon liner and all that.

I bought all the jaz for the .9 wire so i gotta give it a shot, i hear what your saying about the thicker wire but.

The wire is 5356 grade.

I think ill try getting a hand held butane torch and preheat the starting section. Failing that i may try run off plates.

Cheers for the reply's fellas

[bazzle]

Also depends on what your base alloy is your welding in regards to wire .


Bazzle

[tuf045]

just wondering if this is for your intercooler/inlet manifold?

if so you don't know anyone with a ac tig do you? you will be able to get a much better looking weld. just heaps of effort to go to then have the welds look big and fat.

[Z()LTAN]

just wondering if this is for your intercooler/inlet manifold?

if so you don't know anyone with a ac tig do you? you will be able to get a much better looking weld. just heaps of effort to go to then have the welds look big and fat.

Unfortunately not an option.. 100% of this car is built with my hands, im not gonna change that now

On a side note, i think i have the ali welding sorted

[tuf045]

just wondering if this is for your intercooler/inlet manifold?

if so you don't know anyone with a ac tig do you? you will be able to get a much better looking weld. just heaps of effort to go to then have the welds look big and fat.

Unfortunately not an option.. 100% of this car is built with my hands, im not gonna change that now

On a side note, i think i have the ali welding sorted

good to hear..i want to see how much power you make out of this thing

[SWBMQCraig]

So since you have it sorted wanna share your learnings?

I'm thinking of giving it a go with my lincoln 180c..

Cheers

Craig

[Z()LTAN]

Grab a whole lot of scrap mate and just keep testing different settings, and torch angles and work angles.

I found for tacking i had it cranked right up (amps)

When normally welding i had to turn the amps back a bit. Turning the amps back a bit made the first say 1" of weld quite cold, so less penetration. To overcome this i would tack on 'Run off plates' they are a piece of scrap that you tack to the side of the work. You start your weld on there and then run off it onto your work and finish the weld there.

A butane torch and a quick preheat would also do the trick.

I also found that if the work was on a slight incline and i was welding down the incline, i could have the amps a bit higher and not penetrate too far.

Your hand travel speed is almost twice that of when welding steel.

Good luck to anyone who wants to give it a go.

[grundomat]

another thing worth thinking about is, depending on the length of your welds, is turnig the amps down a bit gradually, or have a mate do it, whilst you get further into the weld. the problem with aluminium is that it conducts heat alot faster and a much larger spread than other materials. Also, just to make sure, you are running pure argon as with tig, and not a argoshield or stainshield?

cheerz
Matt

[Ice]

when welding ally your travel speed increases as you weld....

theres a few other little tricks to it, but is achieveable... dont think id try it with a machine under 200amps though...

[SWBMQCraig]

when welding ally your travel speed increases as you weld....

theres a few other little tricks to it, but is achieveable... dont think id try it with a machine under 200amps though...

They sell a alloy spool gun for the 180c might have to check up the thickness's it can actually weld tho.. only need like 2mm max just doing plate stuff really.. sounds like it needs a bit of a knack to get it right tho!

Cheers

Craig

[Clive Rand]

When welding ally, always make sure the metal is clean and use a stainless wire brush to keep it that way. There is always a knack to welding, but mig welding ally is much more forgiving than TIG welding. A general rule for MIG welding is push gas and pull flux, also a good idea to set your welder up on some scrap where possible to avoid any holes in your job at hand. As mentioned before use pure Argon gas, and try for a nice chrome looking weld pool to push along, and train your eyes to see about half a mm in front of the weld and you will see it start to melt as you progress with your weld. Also be sure that you reverse the polarity of your welder when switching from steel to ally.

Clive.

[kx450]

When welding ally, always make sure the metal is clean and use a stainless wire brush to keep it that way. There is always a knack to welding, but mig welding ally is much more forgiving than TIG welding. A general rule for MIG welding is push gas and pull flux, also a good idea to set your welder up on some scrap where possible to avoid any holes in your job at hand. As mentioned before use pure Argon gas, and try for a nice chrome looking weld pool to push along, and train your eyes to see about half a mm in front of the weld and you will see it start to melt as you progress with your weld. Also be sure that you reverse the polarity of your welder when switching from steel to ally.

Clive.

I dont think you should be using a stainless brush on ally.U can get ally brushes stainless brushes put impurities in the ally just like sitting stainless down on mild steel.

[rowenb]

Ally brushes? They wouldn't do much would they? Always just used a ss brush and wiped it with acetone.

[grundomat]

personally, (and i have been doing this for a living for a while now), i keep three brushes in my tool kit, steel brush marked steel, stainless brush marked stainless, and another stainless brush marked aluminium. Aluminium brushes are useless, the bristles bend once, and then snap. Just get timber handled stainless brush, write aly on the handle, and keep it seperate from the rest.

matt

[AFeral]

To get a good clean result turn the gas flow rate up I run 28 litres a minute. A lot of gas i know , this gives a lot cleaner soot free weld.