Question 59 QMED05 - Machinist-Pump Technician

The Correct Answer is D. **Why option D ("a soft-bristled brush") is correct:** When cleaning the cotton cover (jacket) of a fire hose that has become contaminated with oil or grease, the goal is to remove the contaminant without damaging the woven fabric. A solution of mild soapy fresh water is used to break down the grease, and a **soft-bristled brush** is the appropriate tool for agitation. It provides enough friction to lift the dirt and oil from the fibers without tearing, abrading, or weakening the structural integrity of the cotton jacket. **Why the other options are incorrect:** * **A) paint thinner:** Paint thinner is a strong chemical solvent that is generally unnecessary and potentially harmful to the rubber lining and the protective coatings or treatments applied to the cotton jacket of a fire hose. It could degrade the materials. * **B) cornstarch:** Cornstarch is an absorbent powder used to draw out oils, but it is typically used as a pre-treatment or for light spills on dry fabric. It is not an integral part of the washing solution (mild soapy water) and would not be used *with* the solution to physically wash the hose. * **C) a wire brush:** A wire brush is far too abrasive for cleaning woven cotton or synthetic fire hose jackets. It would severely damage the fibers, causing fuzzing, tearing, and permanently weakening the hose structure, making it unsafe for service.