10/13/2026
Ever wondered what happens when you leave compressed air sitting in an air compressor?
That nasty brown liquid is actually a mixture of water and rust.
When an air compressor pulls in air, it also pulls in moisture. As that air gets compressed and cools down, the moisture turns into liquid water and collects at the bottom of the tank.
Over time, that trapped water reacts with the metal inside the tank, creating iron oxide (rust), which gives the water that disgusting brown color.
If you don’t regularly drain your compressor, that moisture can slowly corrode the tank from the inside out, weakening the metal and potentially creating a serious safety hazard.
And yes, all of that came out of our air compressor.
This is your reminder to drain your compressor after using it.