Mig welding

[Aussie Mike]

Hi Pat,

The guy I get all my welding consumables form is a retired welder and he's been helping me with my set up.

The teflon liner is important to minimise drag on the wire in the lead. it also needs to come right back almost to touch the rollers. This reduces the chance of the wire kinking befor it gets into the liner. The roller tension is very important as it has to be soft enough to let the wire slip if you lose your arc and the wire stalls on the work piece. The tip size was a facor too, this guy reccomends using the next size up tip for your torch to reduce the drag on the wire.

The wire I'm using is 0.9mm but I think 1.0mm would be better but I don't have rollers to fit it.

The rollers should be U groved rather than V groved for aluminium as the V grove can distort the wire and lead to easier kinking.

The workpiece needs to be as clean as possible and should be wire brushed imediatly prior to welding to minimise the surface oxide build up which will give a dirty looking weld and might stall your arc. he also recomends keeping a stainless wire brush handy whilst welding to brush of the oxide that builds from the heat of the weld as you go.

I havent had much time to practice aluminium lately since I had a bunch of steel to weld and it takes a while to swap liners and bottles.

I'd like to just run straight Argon for both Mig and Tig regardless of material. I run a normal CO2 Argon mix for for steel and I'm told it has some different properties for penitration and weld spatter than straight Argon but I can't get a straight answer from the gas companies. I'd like to save a few $$ on the extra bottle rental.

I've been taking my alluminium stuff to a pro welder as well but I'd like to be able to set it up at home just for the challenge. Got to do a bit more investigation.

Cheers