# Spindle coolant lifespan?
**URL:** https://forum.pwncnc.com/t/spindle-coolant-lifespan/3539
**Category:** General
**Created:** [October 8, 2025, 9:01pm UTC](https://forum.pwncnc.com/t/spindle-coolant-lifespan/3539 "2025-10-08T21:01:43Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@RasterofPuppets](https://forum.pwncnc.com/u/RasterofPuppets)
#### Post date: [October 8, 2025, 9:01pm UTC](https://forum.pwncnc.com/t/spindle-coolant-lifespan/3539/1 "2025-10-08T21:01:43Z")
How often do you guys change your spindle coolant? I’m using an off the shelf antifreeze premix, and my gut tells me that if it’s not been contaminated and doesn’t see any temperature extremes, it should be good for a very long time. But I’m curious if there could eventually be some sort of build-up or coagulation inside the spindle…? Is it necessary to give it an occasional flush?
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### Author:  [@Chris](https://forum.pwncnc.com/u/Chris)
#### Post date: [October 8, 2025, 9:16pm UTC](https://forum.pwncnc.com/t/spindle-coolant-lifespan/3539/2 "2025-10-08T21:16:28Z")
I use a antifreeze concentrate and distilled water 1:3. It’s sealed from debris. I’ve had the same bucket full for about 18 months but i haven’t used my machine much recently.
Text book answer is annually
I also use a couple of fish tank thermometers. 1 for the numerical reading, the other is a Masso alarm.