What Tig Welder should I purchase?

[BCBoy]

I have been looking at the Tig machines here. The Everlast unit go from 3 amps, 5 amps and 10 amps low starts. How much difference is their between 3 and 5 amps when welding this thin stainless steel? Or could I use a 10 amps machine? I would like a AC/DC machine so I could welding aluminum later on too.

[christian]

Yeah,

That thought occurred to me to, since the iTIG is DC-only, and its price approaches that of an AC/DC TIG unit, which have nearly the same low-amp ability.

I'm guessing that a unit with 10 amp starts would probably do it fine, even though 3 amps might be hard to beat. But I'd still think a specialized fixturing would be in order, with aluminum or copper backing around those areas that any thin sheet mates to the thicker stainless fittings. And I'd always tend to look for ways to have the bead on the inside of a vessel or at the lid or rim of the bulkhead fitting where it fits flush to a sidewall drilled hole, so you can avoid a fillet weld, which takes much more heat and may appear imperfect.

So, yeah, if I were to want to do that stuff, I'd get a TIG unit, some cheap stainless tubing or pipe, along with some cast-off ss kettle or kegs, then practice on the best fit-ups, joints, and welding tactics.

I mean, I use a basic kettle with no fittings for liquid and dry malt extract brews. But in all of he catalogs that I've seen for the more advanced kettles and other vessels, I don't think I've noticed any TIG welded bulkhead fittings. And that fitting that's shown, seems to have no secondary flange seat at the outer wall of the kettle, so that an outer weld with a modified fillet/lap weld might be quite feasible, especially with managing the heat and potentially having an aesthetically pleasant looking weld showing.

So, maybe the silver solder route or whatever is the the more trodden path for that stuff is the smart and easy course. But please do let us all know if you manage to get it done well with the TIG process.

Here's my threaded fitting to the Korney keg. Of course, it's only for a cold storage vessel under a bit of CO2 pressure. But, I believe I did attempt to TIG weld a much smaller, threaded fitting that took a simple cap, years ago, and it didn't go so well.