Category Archives: Metal pretreatment
Click here to view mind map of zinc phosphate crystals Given below the structures of three types of zinc phosphate crystals: 1) Hopeite Source: http://rruff.info/hopeite/display=default/R050254 2) Parahopeite Source: http://rruff.info/hopeite/display=default/R050463 3) Phosphophyllite Source: http://rruff.info/Phosphophyllite
Online zinc phosphate coating weight converter Click here … to convert g/sq. m to mg/sq.ft. or vice versa.
Trouble shooting in a phosphating plant S. No. Problem Cause Remedy 1. Coarse crystal Low accelerator Add accelerator 2. Patchy coating Low concentration of phosphate solution Add phosphate solution 3. Dark brown colour of both solution and substrate Excess … Continue reading →
Sand blasted surface needs no phosphating. Epoxy finishes can be done directly on the freshly sand blasted surface. Sand blasted surface gives coarse phosphate coating Mineral acid pickling results large crystals Organic acid pickling results medium crystals Solvent vapour degreasing … Continue reading →
Basic Types of phosphate coating: Iron phosphating – 30 – 100 mg/sq.ft Zinc phosphating Light – 100 – 400 mg/sq.ft Medium – 450 – 1000 mg/sq.ft Heavy – 1000 – 3000 mg/sq.ft Manganese phosphating – 1000 – 3000 mg/sq.ft New … Continue reading →