Having used a Miller Diversion 165 and having experience TIG welding and teaching TIG welding I have some suggestions:
-Skip the Diversion unless you plan also buying a foot pedal. The finger control is handy for out-of-position welding, but is awkward to learn with. I would consider something from
Everlast which is lighter-duty than the Miller, but a lower cost with more handy features.
-Spend extra money getting one or two good auto-tint helmets. I would get one with at least three light sensors (it sucks if all of the sensors become blocked for whatever reason, never happened with my 3-sensor lens but did with my 2-sensor lens). Observers/instructors can use solid lens helmets with no detriment.
-Get gloves with long cuffs, preferably a cuff that can be cinched over jacket sleeves. I really like my BSX welding jacket and gloves, best I've ever used but not the most expensive. $30 for the jacket and $20 for the gloves IIRC.
-If you're welding aluminum get 50Ar/50He mixed gas, makes TIG welding aluminum much easier than straight argon, worth every penny many times over. Get Ar as well if you plan to do steel welding.
-4340 AL rod will comfortably weld most aluminum alloys, this is your bread-and-butter welding rod. Be careful to ask for TIG
rod, not to be confused with
wire which usually refers to MIG wire.
-With TIG a welding apron isn't typically needed because there are no sparks or spatter.
-Get lanthanated or zirconated tungsten electrode packs (orange band and white band respectively). Pure tungsten is pure garbage and thoriated tungsten is radioactive
. Get lots (1-2 packs of each size) of spare electrodes and nozzles, especially since your team is learning.
-Get a bench grinder to ONLY use for sharpening tungsten electrodes.
-Get an angle grinder with a flap sanding disc, this will make weld prep go very quickly.
-www.weldingtipsandtricks.com is just about the best website for practical welding advice. Jody, the guy who operates the site, is happy to answer questions via email and is very responsive. Read the pages on learning how to TIG weld aluminum, they are very useful.
Good luck! TIG welding is a great skill and not terribly difficult to learn. Just practice practice practice with bead on plate and you'll figure it out!
Feel free to PM or email me (jamesch13[at]gmail) with any questions as well!