Another short timer here, but we have a Miller 150 STH at work that I have used. It stick welds okay on the bench plugged straight into a 115v outlet with no extension cord. I was disappointed in how it worked out in the field where an extension cord is required. It seems once you add an extension you start to get voltage drop. It's an inverter machine and it trips off once the capacitor is discharged. You have to wait for it to reset. About the only rod we can run with it in the field is 3/32" E6010 at about 50 amps and IMHO the welds are too cold. We could never get it hot enough to run 3/32" E7018.
It does come with 230v capability, so maybe the problems I experienced wouldn't be an issue with the higher voltage. We don't have any 230v outlet's so I can't say.
My pardner uses it for TIG welding, which was the reason it was purchased. He's very satisfied with how it does TIG.
I've never welded cast iron. I assume you are talking about the little pointy ornamental parts on top of a gate?
Guys,
Check out some of the posts on the Maxstar 150 over on "Weld Talk" on the Hobart board. The Maxstar 150 has always had a small problem with 6010. However, using 115V (even with a 25' extension cord) with 3/32 in 6011, 6013, 7014 & 7024, (or 1/8" 6011 & 6013), it runs fine, and the tig side of the machine is great. Here is the link:
http://www.hobartwelders.com/mboard/
~thirdeye~