Kool Mist vs straight water?

[Bob Korves]

i use kool mist flood in the lathe, micro drop in the mill (when i use it). my friends in manufacturing all said to stay away from mist

Yes, stay away from "mist." Do not stay away from units that put out droplets instead of mist. There should never be any mist in the air with a mister unit. Small droplets should kinetically impact the work and stay there. Mist in the air is BAD for your lungs and the other parts of your personal breathing apparatus. Fog looks great coming out the nozzle compared to sputtering droplets, but sputtering droplets are what you want to see impacting the work and not going elsewhere. I also think it smart to stay away from coolant sumps that smell like a sewer and/or like rancid oil. Also remember that with water based coolants, it is the evaporation of the water that is cooling the work (540 Kcal/gram.) Flood does not do that, oil does not do that. Highly volatile solvents like WD40 and kerosene do get some cooling from evaporation, but only a small percentage of that of water based coolants that are actually evaporated.

 

[ch2co]

I use WD40 on aluminum only. Seems to work best for me. Otherwise kool mist.

 

[Janderso]

Before going to a spray mist setup, I used to use WD40 as a flood coolant. But, then when I started running higher feed rates, the WD40 would smoke profusely. One time this dude came into the shop because he thought something had caught on fire.

The smoke from tap magic motivated me to go with the ever popular Kool mist 77.
The smoke hurts my lungs. I don’t see how the basement guys on YouTube can stand it.