Granodine 20 produces a fine grained phosphate coating on iron, steel and zinc surfaces which protects against rusting and underfilm corrosion and provides an excellent substrate for paint or other organic coatings. The zinc-calcium phosphate coating is produced in an accelerated dip process which takes just 2-5 minutes at 60-70C.
The Granodine 20 process is suitable for the pretreatment of most ferrous and zinc components including forgings and castings. The multi-stage process is easy to follow and control, and should be observed for best results. It involves pre-cleaning with an alkali cleaner and water rinsing, or solvent vapour degreasing. Rust or scale is removed, and then the item is dipped into the Granodine 20 solution. Rinses in water and Deoxylyte 10 are followed by a final drying stage.
The resulting zinc-calcium phosphate coating has a weight of 2.5-3.5g/m2, and the process is approved to Def Stan 03-11 as an accelerated process (Class II) to meet the requirements of BS 3189: 1991.
