Washing Clay to Prevent Efflorescence: The Number of Wash Cycles That Brings Soluble Salt Below a Visible-Bloom Threshold

This paper addresses white salt bloom appearing on fired bricks and pots made from clay dug near saline ground, spoiling their appearance and weakening mortar bond. It presents a wash-cycle rule that predicts residual soluble salt after repeated washing and settling, derived entirely from stated assumptions and a computation whose code and full output accompany the paper. The sweep covers number of wash cycles from 0 to 6. The headline outcome is: first cycles below threshold 3; salt after 2 cycles pct 0.104; salt initial pct 0.85; water at first ok l 1200. These figures identify a specific operating point or bound that a workshop can apply directly, and they also show how quickly performance deteriorates away from it. No kiln was built, no ware was fired, and nothing was measured for this study. SIMULATED, NOT MEASURED.