I understand that it's about $20 a gallon for Miller or Radnor (AirGas) and some of it is already pre-mixed (cut with water) It almost sounds like I could go broke filing up the tank. I read elsewhere that some folks use RV coolant but I don't know whether that's ethylene or propylene glycol. Yet others say you can use straight distilled water with some "Water Wetter". I'm going on the assumption that distilled water is similar to de-ionized water and would be equally as usable in a welding cooling unit as de-ionized water. I haven't a clue where to get de-ionized water.
I can't seem to find anything from Miller on the topic, either. In fact, the Synchrowave 200 Manual says nothing about a water cooled torch at all. It appears that Miller leans towards the air-cooled torches on the smaller machines.
So my question is, assuming that I use about 7 gallons of distilled or de-ionized water in my 15 gallon tank how much Miller or other brand welder coolant would I need?
Thanks in advance.