Gonna take a small issue here
Not that this has much to do with the original post....... (AC for aluminum for the Original poster)
Thoriated electrodes are certainly not a requirement for Miller inverters like Dynasty.
Thorium will work with advanced square wave power supplies and AC as long as you don't overheat it.
Cerium is a better choice for AC aluminum with Dynasty (as Miller Electric recommends) The reason it is better; is that when cerium overheats, it has a tendency to ball at the end of a pointed tip. (pointed tip also recommended by Miller for Dynasty). Thorium electrodes when they overheat tend to create numerous little growths at the end which distorts the arc, also thorium electrodes tend to spit across the arc rather than ball at the end, they will also split longetudinally when run with alternating current...
Cerium and Zirconium are the electrodes of choice for AC welding of aluminum with inverters or transformer rectifiers..... I would not recommend thorium or pure tungstens as a first choice under any circumstance.
http://millerwelds.com/education/TIGhandbook/pdf/TIGBook_Chpt4.pdfhttp://www.millerwelds.com/education/articles/articles42.htmlhttp://www.millerwelds.com/education/articles/articles43.htmlhttp://www.millerwelds.com/education/articles/articles46.htmlView C is an abused Thorium electrode... if you start to see the little growths, you may assume tungsten has transferred across the arc into the molten pool... and nobody likes that :)