Those of you who actually do metalwork what kind of coolant do you use? Hav e a self-contained system on my lathe and have been using a water based(Tri
-cool?) and have not been happy with the rust that has formed in my tank. I lose a lot from evacuation and generally make up with water but I suspect that is the wrong way to handle things. When I added premix fluid, the flui d would gel up and not go back in solution. Just wondering what others reco mmend. I don't use coolant a lot but every time I need it my tank is empty. Suggestions? TIA