Havent been on this forum for a while now but this thread caught my eye..
Im a sheety by trade but have been doing boilermaking for nearly 4 years now so have done alot of MIG, TIG and ARC welding.
30ed32- TIG's can also be used as an ARC welder, you just need to remove the TIG torch and attatch the ARC hand piece and change a couple of settings depending on what machine you have.
I have a UNI TIG AC/DC welder http://www.bridgeswa...p?ProductID=217 that i use at home mostly just to make things for myself. Its packed with heaps of features and even has a wheel on the torch (like a mouse wheel) to adjust the amps.
A tip i havent seen anyone say yet is to keep your hands as steady as you can.. You can be the best welder but if your hands are moving around and it dosnt need to be much at all (a few mm) then the weld pool will follow and you will end up with a weld that can be messy. I always try to support my arms on something, like ill use my elbow as a pivot point or if there ist anything to rest on then ill tuck my arms into my chest area just to keep steady.
The DC TIG's can be good to use but for a first timer they can be frustrating. The reason is that they are a scratch start, meaning that you need to scratch the tungsten tip on the work to strike an ark. When you're learning to TIG you will end up grinding and re grinding the tungsten enough times to drive you crazy. If the tip isnt a sharp point then the arc will wander around and will make it hard to control the weld pool. AC/DC has HF (high frequency) start meaning that when you press the button (or foot pedal) then the arc will automatically start or jump to the workpiece without touching it, plus with AC you can weld ally.
And 1 last thing for now that a few people dont know.. When you finish your TIG weld and you get that little pin hole in the center of the weld pool, that is from the arc suddenly stopping. If your TIG has a downslope setting you can turn it up a little bit to stop that from happening. For those that dont know, the downslope can be used to make the arc slowly fade out instead of a sudden stop. Just remember to turn up the post gas flow aswell if you turn up the downslope