Abstract: Acid cured, polymer protective layers are bonded to metal or cement surfaces using a primer coating of an acid stable, thermoplastic elastomer such as a block copolymer of styrene-butadiene.

Abstract: A pulverulent single component potassium silicate cement composition is disclosed and claimed which is capable of being installed by the dry gunite method utilizing water addition at the nozzle to produce a dense continuous quick setting acid resistant cement on horizontal, sloping, vertical and overhead surfaces. The cement composition comprises a special hydrated potassium silicate water glass powder, an acid releasing hardener, and a filler such as silica sand. The composition of the potassium silicate and the proportions of the ingredients must be closely regulated to obtain satisfactory cements. The potassium silicate cement opens a new era of silicate monolithic linings which provide maximum resistance to acid environments other than hydrofluoric acid.