Spraying of coal in an open top hopper car with an aqueous composition containing at least about 2.5% of a binder material consisting of solid material in an aqueous suspension of an asphalt emulsion or a black liquor lignin product and containing 0.1 to 2.0% of water soluble ethoxylated alkyl phenol or sulfo succinate wetting agent results in the formation of a crust layer which provides protection against loss of coal due to wind action during rapid movement of the car.