I just bought an old (30 years) Idealarc tig 250/250 that had an Old (30 years) Dyna-Flux water cooler that the coolant has started to jell/gum up and is stinky. This is my first cooler setup for a tig torch, I probably don’t need it at all but, I figure I have it I might as well use it. I called Dyna-flux which by the way is still in business and seem to be great people to deal with. They told me that I needed a 929 or 927 fluid for the unit. One is concentrated and the other is pre mixed. What is you guys experience with coolant types? Can you use an automotive anti freeze? It seems to be the same type closed system? I know the dyna flux coolant isn’t very expensive but, getting the stuff and making sure you always have some on hand seems to be a pain if the automotive type will work you can at least run up and get some on the weekend if needed.