The Transmig 175i always gets a good report in everything I've seen over the last couple of years.
I've got a bigger 250A Unimig and very happy with it. I recall something about a split warranty with Unimig - something like 12M on circuit boards and 3 years on hardware which might help explain the differing warranty periods you're being told.
Mine hasn't done a lot of work, but is now my preferred welder whereas I tended to pick up the stick welder for quick jobs when I only had a cheap&nasty MIG.
Be aware that you need to run straight Argon for TIG, so unless you're seriously going hire another bottle and use it, IMO you'd be better to swap the TIG torch out for something you're actually going to use if you get the chance (an initial gas fill, or auto welding mask etc).
Steve
1985 County - Isuzu 4bd1 with HX30W turbo, LT95, 255/85-16 KM2's
1988 120 with rust and potential
1999 300tdi 130 single cab - "stock as bro"
2003 D2a Td5 - the boss's daily drive
Bookmarks