Self Help Maintenance Tips: Mig Welding Ally

[Burytreeman]

Hi all i thought i would start a new thread for those of us mechanically minded who like Tinkering..

I am interested in those of us who may have tried aluminium welding, with a Mig set? and what sucsess or failures they encountered..

 

Any Takers? (Andy?)

[treequip]

it can be done but TIG is vastly superior

[mixedangased]

yes tried it once yrs ago with a eland 160 amp mig,

used 1mm wire and not very successfull as couldn`t turn the power down enough.

had it on lowest setting and the wire speed flat out trying to weld alloy plate it welded of a fashon but not good.i wouldn`t bother again.

better off with a tig as said above

[Reddog]

As stated above TIG is much easier to control for small jobs.

In order for MIG to work right it takes a machine designed for Alum. Most have a pulse setting and different high frequency settings, that all need to be adjusted based on alloy and weld configuration.

Small structural pieces are easier to MIG than large flat panels. Large panels take some trial and error to reduce warping and distortion.

Also Alum takes a lot of heat to weld, so very quickly you can go from great to a giant melt hole in seconds.

[Burytreeman]

Im not sure i want to know but whats the cost of a half decent Tig setup?

[Peter]

Not as much as they used to be, inverter technology has brought the size weight and price down. Probably £800-1000. You will need an AC set to TIG ali though, and pure argon, so probably not cost effective for the odd weld here and there.

[woody paul]

Never tried it. But I had a alley tool locker made by a company and the lad there could weld alley with a mig, but he was doing all day long he could probably do it standing on his head by the Finnish on my locker.

[twistedhicap]

For a good AC TIG machine you would be looking for around £1500 but to be truly versatile you would want to have a water cooled torch set up and a foot pedal control as said due to the aluminiums capability of carrying the heat from the weld you need more current than on steel but to be able to get it right you really want to be able to vary it to where the foot pedal comes in ans too cope with the heat at the torch the water cooling.

 

Mig welding aluminium is straight forward but again the kit is more specialised as the Filler wire is so soft you need a different liner int he torch and different feed rolls ! better still and the way we do it with ours is a "pull" torch it has a feed roll and motor int he torch end so it pulls the filler wire along the torch rather than relying on the machines feed rolls to push the soft filler wire to the tip of the torch!

 

We weld with both TIG and MIG on aluminium, stainless and mild steel !

 

When welding aluminium you need to use Pure Argon gas and the parts to be welded need to be spotlessly clean and the oxide layer to be removed otherwise poor welds are likely.

 

Also you need to know what the parent Aluminium composition is two main types either Magnesium alloy or Silicone alloy you need to know to know which rods to use !

 

Also preheating helps on some welds and welding older aluminium can be fun ! just spent a day welding up the gearbox casing on an Audi TT quatro that had a couple of inch long cracks in it but due to the absorption of oil into the metal and the cracks it took almost a day to drive the oil out of the weld areas and to get a decent weld.

[Burytreeman]

Thanks peter, i seem to have a habit of buying expensive tools to use on an occasional basis.. any reccomendations on models anybody? i have a small kemppi inverter stick welder which is a good unit..

[twistedhicap]

the Esab units are great thats what we run the miller sets are good too ! murex not bad

 

ours will run from a 13 amp plug

 

Re the gas there are a couple of firms doing rent free bottles you basically buy the bottle at a discount and they refill them !