Definition
A strong, fast-evaporating organic solvent (chemical formula C4H8O, also called MEK or 2-butanone) used in aircraft maintenance to clean surfaces, thin certain dopes and lacquers, and prepare materials such as fabric, fiberglass, and metal for bonding or finishing.
Plain English
A powerful cleaning and thinning liquid used in aircraft shops. It cuts through grease, old finishes, and residue, and dries very quickly.
Context Anchor
Seen in aircraft maintenance manuals, shop procedures, and material safety information when cleaning or surface preparation is required before a repair or finishing step.
Derivation
The name describes its chemistry: a 'ketone' is a family of organic compounds with a specific carbon-oxygen structure, and the 'methyl' and 'ethyl' parts name the two small hydrocarbon groups attached to it. Knowing it is a ketone tells a mechanic it behaves like other strong, fast-drying solvents in that family.
Why Pilots Care
Proper surface cleaning with this solvent ensures paint and sealants adhere correctly, preventing corrosion and structural issues later.
Grounding Statement
If a maintenance procedure calls for Methyl-Ethyl-Ketone, picture a powerful, fast-drying shop liquid that cleans aggressively but must be treated as both a fire hazard and a fume hazard.
Intuition Check
Do not treat Methyl-Ethyl-Ketone as a general-purpose cleaner. In aircraft work, it is a strong solvent used only where the approved instructions and material compatibility allow it.
Example Sentence 1
The mechanic wiped the metal patch with methyl-ethyl-ketone to remove oils before applying the bonding primer.
Example Sentence 2
Methyl-ethyl-ketone dries in seconds, making it suitable for quick cleaning tasks on the flight line.