Shree Rasayani’s ACZ acid zinc process produces brilliant, ductile and corrosion resistant zinc deposits on iron and steel parts in barrel and vat. As is necessary for all acid electrolytes, the parts must be thoroughly pre-treated. SOLUTION MAKE-UP: (A) BARREL SOLUTION ACZ Base Solution (A) : 140 to 180 ml ACZ Conducting Salts (B) 150 to 200 gm ACZ Wetter (MN) or ACZ Wetter (M3) : 30 to 40 ml ACZ Brightener (RN) or ACZ Brightener (R3) : 0.2 to 1.0 ml. Water : Make up to 1 litre It is preferable to start at lower concentrations of brightener and then increase the quantity gradually as required. (B) VAT SOLUTION ACZ Base Solution (A) : 160 to 200 ml. ACZ Conducting Salts (B) :120 to 200 gm. ACZ Wetter (MN) or ACZ Wetter (M3) : 30 to 40 ml. ACZ Brightener (RN) or ACZ Brightener (R3) : 0.2 to 1.0 ml. Water : Make up to 1 litre. The above examples are for typical barrel and vat solutions; the formulations can be changed as required. ACZ Base Solution (A) is used for controlling the zinc content in the bath. Potassium chloride and boric acid are introduced to the bath through ACZ Conducting Salts (B). The function of chloride is to provide proper conductivity to the solution. Higher concentrations increase conductivity and are usually required if plating is done at higher current densities. Low concentrations can cause anode polarisation and subsequent decrease in the operating pH. Boric acid is required in the solution to minimise pH fluctuations. A low concentration reduces the desired buffering effect and can cause the bath pH to rise during normal path operation. ACZ Brightener (RN) and controls deposit brilliance. It works synergistically with the ACZ Wetter (MN) in providing deposit uniformity