Please help - How do I weld aluminium using my MIG?

As long as you are not having problems with wire feed, I wouldn't sweat getting a U groove wire feed roller. If you get some 4043 wire, you might start having problems and need a U groove roller.

Try using a sander or just some sandpaper to get the oxide off the old cutoffs. And then wipe with a paper towel moistened with a solvent. If you sand the aluminum it will get rid of any thick oxide layer. You might want to use that stainless wire brush a few minutes before you weld. Aluminum gets a thin oxide coating very rapidly.

You can use a plastic bag over the nozzle and see how fast it inflates. It takes some math to convert from seconds per gallons to get cubic feet per hour, but should be much easier in metric to use a bag of liter size and get liters per minute.

Dan

The main problem here seems to me that cheap MIG sets with aluminuim windings, sre not that great for welding aluminuim, and unless everything is spot on, you are likely to have problems with feeding aluminuim wire. Also be aware that if you are using small disposable gas bottles, this may well be causing your problems.

If you need to do a one off job, then it might be better to hire more appropriate equipment, if you need to do aluminuim on a regular basis, then dependant on what you want to do, either an industrial quality MIG with a spool gun, or an AC/DC TIG, with at least 200amps.

Depending on the type of welding machine you have, you might need to reverse the polarity of the leads in order for it to work properly.Recently bought a wire feed machine that used flux core wire. When I added the gas flo-valve to it I had to reverse the polarity to get it to weld right. B

You do need to reverse polarity to work with flux core, but never heard of any need to do this when welding alluminuim.

k

From a quick search the 5356 you are using is a 5% Mg alloy. Thanks for clarifying the thickness as just quoting 16g and 10g is ambiguous for an international audience as I would expect the US readers to assume 16awg (0.051") and 10awg (0.102").

H>Hi,

Two web sites which may be helpfull.

(This looks very good - haven't tried welding ally myself so I may be wrong)

Great link full stop (period !) Thanks for that.

Steve

Note that the Alcotec site has a bit about using a CC power supply to weld aluminum with a wire feed welder. I don't think they are talking about using a special variable speed wire feed. Just using a CC power supply instead of a CV supply.

Dan

Paul Bohanna ha scritto:

Alluminum welding need: pure Argon (8-10 lt/min), a teflon liner, a contact tip for aluminum ( if you have not put one for 1mm) a roller with a U grove (if you have not put one of 0,6mm V grove) The welding wire must be compatible with the base material (in any case you can try a 4043) For the thickness that you must weld 1 - 1,6mm with filler wire of 0,8 mm the speed of the wire must be approximately 6meter/ minute. Put the welder to the minimal regulation. The type of defect that you describe can be of two types: if the drop of molten metal fly in the arc whithaut tuch the base material you have insufficient wire speed; if the wire tuch frequently the base metal and the sound of welding is like a machine gun you have too much wire speed. The sound of a correct regolation in short circuit is like when to fry eggs. Remember you must weld from the right to the left.

Two web sites which may be helpfull.

(This looks very good - haven't tried welding ally myself so I may be wrong)

Ian McDonald