We recently touched on greases being available in a wide variety based on application but the real question is, “Are all greases compatible?” The short answer is, “No”.
All greases contain a thickener (which helps with its physical state). Thickeners vary depending on application (such as temperature, water resistance etc). As such, to verify whether two greases are compatible or not, Machinery Lubrication developed a Compatibility Chart based on thickener type.
You can determine the thickener type by looking at your Data Sheet or talking to your OEM. Not all greases are compatible, so be careful when mixing greases!