Mig welder purchase. Unimig?

**350RRC** · 2nd March 2016, 07:32 AM

Originally Posted by Toxic_Avenger

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** · 2nd March 2016, 05:39 PM

Originally Posted by Don 130

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

Argoshield Light.

**Don 130** · 2nd March 2016, 06:12 PM

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** · 2nd March 2016, 07:00 PM

Originally Posted by Toxic_Avenger

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** · 2nd March 2016, 09:38 PM

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** · 7th March 2016, 08:45 PM

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.

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