Masonry construction/mortar: Worker cleans mixer that produced mortar for laying rock wall. Mortar mixer has two main sections, the motor on left and the mixing drum on right. It can be towed, traveling on its two wheels behind a truck with trailer hitch. Masonry mortar is mixture of sand, portland cement or masonry cement, and water. At end of day mixer drum is coated with hardened mortar that must be cleaned off. The worker bangs outside of drum with small hand sledge hammer to break up mortar on inside surface of drum. He then rinses it out with water, checking it at end to be sure it is clean enough. Ann Arbor, Michigan 2005.