A trade name turned shop and military slang for any heavy petrolatum or wax-based rust-preventive compound brushed, sprayed or dipped onto steel for storage and shipping. It sets to a brownish, sticky coat that keeps moisture out for years and has to come off with solvent or heat before the part goes into service. Left inside bearings or gearboxes, it contaminates the fill and can starve the contacts.
Heard on the job
Spare gearbox showed up full of cosmoline, give it a solvent flush before anybody fills it.
Insider tip
On big parts, hot water or steam softens cosmoline faster than solvent alone, but dry and oil the steel right after.
Also heard as
- rust preventive
- RP
- slushing compound