Stormin Mormon wrote:

Refrigeration mineral oil needs to be used in a sealed system wtih no air or
moisture. It absorbs moisture, and won't be good for your air tools. Likely
to cause corrosion.


R-12 MINERAL oil does not absorb moisture. POE R-12 compatible oil (aka
'Ester oil') does. So does PAG oil for R-134a systems.

Still, air-tool oils have properties (anti corrosion, surface tension,
seal compatibility etc.) that R-12 mineral oil isn't optimized for. I
wouldn't use it in any air tool I cared about.