Coolant and rust

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H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Sep 19, 2014
For you guys running water soluble oil/coolents be careful with the concentration you run. Often they are designed to work only within a percent range of mixture, example only 25-30%. That window keeps everything in solution. Outside of that it starts to separate and that causes problems. The separation can occur immediately, within minutes, or longer. Use what works for you but start with the directions.

From a once upon a time lubricants and violent chemist

Charles Spencer

Active User
H-M Supporter - Silver Member ($10)
Aug 29, 2013
I don't know what size machines you are running. Most of my machines are small: 9" lathes, benchtop mill, Chinese mill-drill, upright bandsaw, power hacksaw, and drill presses. I've always just used cutting oil, either brushed on from a magnetic base bottle or spritzed on with a spray bottle. If it smokes then I turn a fan on it.
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