Definition
A colorless, highly flammable liquid solvent (chemical formula CH3COCH3) used in aviation maintenance to thin certain dopes and lacquers, clean surfaces before painting or bonding, and remove old finishes. It evaporates very quickly and dissolves many oils, resins, and plastics.
Plain English
A fast-evaporating liquid cleaner and thinner. It cuts through oils, paints, and old finishes, and is commonly used to prepare aircraft surfaces for repair or refinishing.
Context Anchor
Seen in aircraft maintenance, shop procedures, cleaning instructions, and material safety information for solvents.
Derivation
From the Latin acetum meaning 'vinegar.' Acetone was first produced by heating the salts of acetic acid (the acid in vinegar), which is where the name comes from. Knowing this hints at its chemical family rather than its everyday use as a solvent.
Why Pilots Care
Acetone is highly flammable and its vapors can ignite easily, so it must be handled with care around aircraft, especially near fuel systems or during hangar work. It can also damage certain plastics, paints, and composite materials if used on the wrong surface.
Intuition Check
Do not treat acetone as just another harmless cleaner. In aviation use, it is a strong, flammable solvent that must be matched to the material being cleaned.
Example Sentence 1
The mechanic wiped the metal patch with acetone to remove oil before applying the primer.
Example Sentence 2
Acetone was applied to the metal spar to clean off grease prior to the inspection.