Mig welder purchase. Unimig?

[Don 130]

I'm looking to buy a cheap mig welder to fabricate some stuff from square hollow tube. I don't want an expensive one as I've got a very good stick welder for heavier stuff. I'm looking at this (http://www.unimig.com.au/catalogue_product.asp?product=935&category=1&subcategory=1) . Does anyone here have experience with these or recommendations for something else in the price range, or advice generally. Thanks.
Don.

[Slunnie]

I've no doubt you will find that to be a really good unit. It looks like it is specced up well for home use. Our 6 MIGs are going all of the time and our 2 oldest machines are Unimig. For home welding that will be more than enough.

[Don 130]

Anyone else with ideas?

[Don 130]

I'll be mostly welding light square hollow tube and thin sheet like body panels. What gas is recommended?
Don.

[Homestar]

I'll be mostly welding light square hollow tube and thin sheet like body panels. What gas is recommended?
Don.

Use an 80/20 or whatever MIG gas blend your local supplier does. Corgas do bottles with no rent - just a one off deposit - doesn't matter how long you have the bottle. :)

When I click on the link, it goes to the home page of Unimig - what model are you looking at?

Whatever you buy, make sure you can get spares for it - tips, shields, rollers, liners, etc. Parts for some cheaper machines are non existent but I doubt that is the case with a Unimig machine, but worth checking.

[Toxic_Avenger]

I'll be mostly welding light square hollow tube and thin sheet like body panels. What gas is recommended?
Don.

C02 up to say 5%
Oxygen up to approx 3%
Balance argon should do it.

BOC's Argoshield light
Coregas 5/2
Air liquide Arcal 5

CO2 gives weld penetration, oxygen assists with weld finish / bead profile, argon is the shielding part. So choosse your poison.

[Don 130]

Homestar,
Quote
"When I click on the link, it goes to the home page of Unimig - what model are you looking at?"



This is the one
https://www.vektools.com.au/unimig-gas-gasless-mig-welder-180amp.html

Don

[350RRC]

Nice price.

I use an old CIG stick welder for mild steel and cast (yes I can weld cast.......without all the BS on the net and the right rods).

I'm interested in something like this Unimig for welding thin stainless.

Comments invited from all you erudite gents please!

cheers, DL

[Toxic_Avenger]

Nice price.

I use an old CIG stick welder for mild steel and cast (yes I can weld cast.......without all the BS on the net and the right rods).

I'm interested in something like this Unimig for welding thin stainless.

Comments invited from all you erudite gents please!

cheers, DL

I've never had to weld cast iron, but hear there is a bit of an art (Black magic?) to it...

So what was your chosen method?
High nickel castcraft rods, or something more run of the mill with plenty of prep, pre heat, cool down and peening?

[roverrescue]

DL
Outline thin stainless a little more.
I have MIG stainless but you will need specific tri mix gas not really suited to mild steel plus pretty Exe spools of wire.

For heavy stainless I stick weld
Light stainless I scratch start TIG with straight argon (which I already have for al and Si bronze)
Also have bottle of argoshield light for carbon steel

For truly thin stainless where you are running 20 A or so TIG might be a better choice? Unless you be welding miles of sheet

S

[350RRC]

I've never had to weld cast iron, but hear there is a bit of an art (Black magic?) to it...

So what was your chosen method?
High nickel castcraft rods, or something more run of the mill with plenty of prep, pre heat, cool down and peening?

High nickel castcraft rods and turn the amps up to 140 (max on these old things).

I read all the stuff on the net about heating and tried it all which was very fiddly.

Now I just clean the weld area up with a grinder, tack it then go. No post-heating.

Has worked just fine on a cracked old wood stove front, broken handle on a very old (valuable) automatic wine bottle cork puller, broken MF steering box case, etc.

Maybe just lucky.

DL

[Slunnie]

I'll be mostly welding light square hollow tube and thin sheet like body panels. What gas is recommended?
Don.
Argoshield Light.

[Don 130]

I think I'll shop around for a bought bottle as well. Paying rent on an infrequently used item would not please me.
Don.

[crash]

I've never had to weld cast iron, but hear there is a bit of an art (Black magic?) to it...

So what was your chosen method?
High nickel castcraft rods, or something more run of the mill with plenty of prep, pre heat, cool down and peening?

I have only done it once many years ago, on an exhaust manifold - had it bolted to a frame work to prevent warping, pre heated in an oven (did not have an oxy)and used a special nickel rod, and peened afterwards. Was on the vehicle for a few years before I sold.

[roverrescue]

While we are talking cast iron. If the repair is not highly structural so think aesthetic, or sealing gases like a manifold OR if you need to machine the part afterwards think fubarred weird arse trailer hub with spun bearing

I have had great results MIG ing silicon bronze. It wets out brilliantly on cast, machines like butter afterwards and really has reasonable strength of repair

Steve

[Don 130]

I sent Unimig an email asking about parts availability into the foreseeable future.
I've copied the reply below.

"Yes we have all the spares available and for all our machines we have guarantee to supply spare parts for at least 15 years after the machine has gone out of production and the Mig 180 is still in production.

Kind regards,"

Don.