A mortar mixer blends sand, cement, and water into mortar. It is a machine with a rotating drum or paddle. It is different from a concrete mixer, which uses a rotating drum and a different mixing action. A mortar mixer has a stationary drum with a paddle that turns inside it. The paddle folds and shears the mortar, creating a smooth, consistent mix. The mortar mixer is used on masonry projects where large quantities of mortar are needed. It is faster and more consistent than mixing by hand.

Mortar mixers come in several sizes. A small portable mixer holds 2 to 3 cubic feet and is used for small jobs. A standard mixer holds 6 to 8 cubic feet and is the most common. A large mixer holds 12 cubic feet or more and is used on commercial projects. The mixer can be powered by an electric motor, a gasoline engine, or a tractor's power take-off. It can be towed to the site. The drum is loaded with sand and cement, and water is added while the paddle turns. The mortar is mixed for several minutes and then discharged into a wheelbarrow or a mortar board.

Mortar mixers require maintenance. The drum and paddle must be cleaned after each use. Dried mortar is hard to remove. The bearings and gears must be greased. The blades must be inspected for wear. The engine must be serviced. A well-maintained mixer lasts for years. A neglected one breaks down on the job. The mortar mixer is a simple machine. It saves time and labor. It is the unsung hero of masonry construction.