The fulling mill, a traditional, hydro-mechanically-run installation, was acquired by the museum in 1965. The mechanism incorporates four crosswise hammer-beam trusses (two pairs) to form the walls of the stone and wood construction covered with a wooden-tiled rooftop.
The fulling mill was used to thicken and finish wool fibers which were later suitable for sewing winter clothes. This is how the fulling mill works: first, the fabric roll is placed inside the hollowed out part of a tree trunk, also known as a pot. Next, the large wooden hammers (Romanian: “maie”) – powered by a hydraulic wheel which is set in motion by the cams on the shaft – crush the textile for 10 to 15 hours. The constant spin is possible because the hammers are carved with increments so as to provide a steady and continuous movement. As the fabric is pressed and dampened in cold, then warm water, it stiffens and turns into felt.
Homemakers would turn this black or white felt into thick winter attire such as coats, trousers and gilets. When the wool fabric is not processed in a fulling mill, it cannot be used for making clothes. Before its invention, the soaked cloth was commonly crushed using a mallet or a pestle.