Flood coolant/oil options

[MyLilMule]

I'm getting closer to getting the K&T 2HL back up and running. Starting to look at coolant options. I'd like to stay away from water based coolants. The way these machines route the coolant back into the sump leaves plenty of places for rust to form. I'm completely in the dark if water soluble oil presents the same risk.

A friend suggested Ridgid Nu-Clear Threading Oil, but it is $175 for a 5 gallon pail (the capacity of the sump).

Just looking for other opinions and options.

 

[mksj]

The better water based coolants do not cause rust and also are less likely to go rancid. I have used Koolrite 2290 in my bandsaw in Tucson with blazing hot summers, and the stuff lasted over a year and no rust or stench from sitting. I currently use it in a Fogbuster type system on my mill at 10% concentration and have not had any issues, it also significantly improves the milling finish. There are other ones that people have recommended. One concern with many of these coolants is respiratory inhalation with subsequent irritation/sensitivity and also skin sensitization. One thing to note is that over time you get some evaporation/loss so you should check the specific gravity to determine the concentration.

KOOLRite 2290 Long Life Coolant