What is the purpose of sheet metal covers on brush stowage tanks?

• A. To vent fumes
• B. To prevent evaporation of volatile solvents
• C. To reflect light
• D. To keep brushes dry

Answer: (B)

Sheet metal covers over brush stowage tanks are there to minimize the loss of volatile solvents. By covering the tank, the surface is protected from air, which slows the rate at which the solvent evaporates. This helps keep the solvent on hand for use, reduces the amount of vapors escaping into the work area, and lowers the fire and health hazards associated with volatile solvents.

Ventilation isn’t the goal here—those covers actually reduce evaporation, not promote it. Reflecting light isn’t relevant to storing solvents, and keeping brushes dry isn’t the primary purpose of the cover, since the main issue is solvent retention and vapor control.