AeroShell Fluid 1 is a light lubricating mineral oil containing, by specification, less than 0.10% mass stearic acid.
For use as a lubricant where a light anti-freezing oil is required, e.g. on aircraft instruments, gun mounting buffers, hydraulic couplings, controls, door hinges, etc. Also used as a preservative oil for Stromberg carburetors and some fuel systems.
AeroShell Turbine Oil 3 can be used as an alternative to AeroShell Fluid 1, but AeroShell Fluid 1 must never be used as an alternative to AeroShell Turbine Oil 3.