Check the listing for details. Eaco Chem Calcite Presoak - Remove Calcite from Clay Brick - 1 Gallon. Condition: New. Listed at 37.50 USD. 1 GallonRemoves Calcite on Clay Brick (Only!)Calcite Presoak is designed as a pre-soak to facilitate the removal of calcite on clay brick (USE ON CLAY BRICK ONLY). Used in conjunction with NMD 80, this combination will ensure the complete removal of calcite.First apply the Calcite Presoak undiluted and allow it to dwell on the surface for approximately five minutes. Repeat this process without rinsing until little pin holes have opened up. Then apply NMD 80 diluted four parts water to one part solution (4:1) without rinsing off the Calcite Presoak; allow a five to ten minute dwell time. Rinse completely to get the desired results.For Use On: Clay brickUse to Remove: CalciteProduct DetailsPowerfully penetrates and softens calciteCoverage rates will vary based on severity of calcite build-up. Proper testing will determine actual coverage rate.