Many of us spend a lot of time cleaning our guns and knives but how many of us actually devote time to clean our flashlights? A good flashlight can last a long time if you remove grime from it on a regular basis, check the parts, and use quality batteries.
Most failures of flashlights are due to dead or reversed batteries however cleaning a light is a sensible thing to do. Think about how many times you lubricate your weapon but have you ever done the same with the threads on your flashlight? If dirt and grease build up along the threads over time it may be difficult to separate the light's body from its head. Battery corrision can complicate matters as well.
Consider how light passes through the lens. Doesn't it make sense to keep your lens clean and scratch free? Like any other tool you use cleaning will improve parts performance and lessen the chance of the item failing at a critical moment.
A well maintained flashlight can perform just as well as when it was originally purchased regardless of it being stored for a period of time. A flashlight in transit gets scratched and dinged. Carry a light in holsters allows dead skin and sweat to accumulate into black grime inside your flashlight. Cleaning reduces the probability the flashlight will have to be replaced or repaired.
Cleaning the exterior is simple enough to do. Remove any dirt by using a lint free fabric or pad and a silicone based cleaner or alcohol. A cloth, paper towel, or similar absorbent material will do in a pinch if you don't have swabs. Read the instructions that came with your flashlight; usually there are recommendations on what cleaners to use on the flashlight and the lense.
Cotton swabs and pads dipped in alcohol are usually sufficent for cleaning a flashlight however some dirty lights may need more attention. Every six months is sufficient enough time between cleanings. Clean the outside by wiping the entire tube down with the pad. A file or a gentle sandpaper can remove burrs caused by coins from your pockets scratching the flashlights exterior or from dropping the light onto concrete.
Provides an extra step insuring that metal connections are cleaned and protected.
Flashlights are only useful if it is working. Sounds too obvious but that's the truth. Regularly check your flashlight and change the batteries in order to prevent corrision.