Thread: Can I tig weld with this unit?

No

You need an AC machine for Aluminium

Damn....
What your thoughts on this unit W240 | MINI MIG 180 MIG Welder | machineryhouse.com.au with the thought of maybe down the track adding a spool gun and welding Alu with it?

It's a transformer machine, very low duty at 180 amps, a mere 10%. Save some more and get a 200 amp inverter MTS (MIG TIG STICK).

Best Regards
John

MIG is a DC process....
As DJ's timber said: you need an AC welder for aluminium. You also need High frequency to clean the weld surface and start and keep the arc going.

A DC mig will weld aluminium just fine.

I doubt the machine you listed would be much good though.

I read a thread earlier where someone said 150 amps minimum for welding aluminium, so I was kinda hopeful that this one being 180 amps it would be suitable.

What thickness aluminium are you looking to weld? 180 amps will weld 6mm but not for very long. 10% of 10 minutes is 1 minute

Originally Posted by brenton21

What thickness aluminium are you looking to weld? 180 amps will weld 6mm but not for very long. 10% of 10 minutes is 1 minute

Hi Brenton, Not exactly sure of the thickness just yet as I have thought out the materials at the moment....
I'm interested in how you come up with 10% of 10 minutes what is all of that based on?

in my experience the duty cycle of a machine is based on a 10 minute period. the mig welder in your link is rated at 10% @ 180amps.

Originally Posted by brenton21

in my experience the duty cycle of a machine is based on a 10 minute period. the mig welder in your link is rated at 10% @ 180amps.

Even worse still - some cheapies are rated on a 5 minute cycle!
Cheap MIG welders are always a poor economy, you really do get what you pay for at the bottom end of the market, however a top of the range machine is not needed for most applications either.
I am not as besotted with the inverter machines as many are and would prefer a good solid transformer unit as a general rule, they seem to give far less problems and if they do they are always cheaper to repair.
Don't be too hung up on a spool gun either, with the correct liner and basic good practices, ally wire will feed very well without one.
Technically, ally can be welded with DC, provided that the electrode is POSITIVE, (I have actually done this), however you will need high amperage due to the heat bias being 2/3 electrode and 1/3 work, this then requires a large electrode to handle the heat. I add this only as a curiosity and would never actually recommend this as a long term option. High Frequency has nothing to do with the cleaning action of AC current, all it does is keep the arc going as it transitions from its positive to negative polarity. The electrode positive phase cleans and the electrode negative heats the work due to the fact that electrical current flows from the negative pole to the positive with a 2/3 heat bias towards the positive pole.

uni mig are not total crap through. For a home handyman use, l would think it would do a reasonable job. Same market as a lincoln 180c (30% @ 130 amps) which have proven alright.

Originally Posted by brenton21

uni mig are not total crap through. For a home handyman use, l would think it would do a reasonable job. Same market as a lincoln 180c (30% @ 130 amps) which have proven alright.

A lot of people seem very happy with UNI MIG welders, I can't say I am one of them as I have not been impressed by the way they weld inasmuch as they seem to have a very rough arc. The Lincoln also seems very popular and has many satisfied owners. If it were me, I would seriously consider a second hand unit of a higher quality, (they can be hard to find though).
I guess what I am really driving at is to avoid Ebay specials and cheap multi process machines without needing to go to the expense of high end machines such as Kemppi or Fronius and to put good knowledge and practice above gimicks.
Ideally, any prospective machine should be trialled before the hard earned is handed over.

Originally Posted by Karl Robbers

A lot of people seem very happy with UNI MIG welders, I can't say I am one of them as I have not been impressed by the way they weld inasmuch as they seem to have a very rough arc.

These days you can't make a blanket statement about a brand, particularly those which are all sourced out of China. I'm sure there are nasty UniMIGs, the one mentioned looks to be a transformer type - I suspect the inverter versions perform better. On the weekend I was at a field day which had a few brand name as well as generic brand welders on display, and having looked closely at a few, I'm pretty damn sure the guts of many of them are virtually identical - the CIG 175i being one of them, and I'd lump the UniMIG 190 inverter combo MIG, Tokentools machine and a few others into the same basket.

The moral is that in the range of "value" brands, you have to go by people's experience with a *specific* model of machine, not the brand in general.

Thanks for the replies guys.
Damn so much to take in when it comes to welding.....! It takes you by surprise when you get into the nitty gritty of it all.
I think after reading all of the comments for what I plan on doing this Uni Mig 180 would suit me. I've given up on the idea of welding Aluminium with it as I wouldn't be doing enough to justify the cost. I do still want a mig though as I've grown tired of the stick welder and after a discussion with a guy at ADG welding today I think this unit will be OK for me.
I can't say that I'll be welding anything thicker than 2.5mm maybe 3mm tops more 5% of the time so the cr@p duty cycle on 180amps aren't going to be a real issue for me I think. I have no large fabrication jobs coming up, most welds will be short bursts anyway and if this changes in the future I think I'll change the unit to suit also.

I did however find out that this unit is on a 15amp plug which is a bummer - but I've been told by so many people to either file down the earth pin or make an extension cord with one end 15amp female. I must say this is a bit of a worry for me though...