Dacrotizing For Auto Components
? A patented process of zine and aluminium flake coating, is better
option to overcome problems related to ordinary zinc plating once
the passivation film wears off. Corrosion is a major problem in
autombile components and fasters. This dacrodip sol is a dispersed
aqueous sol made out of metallic zinc and aluminium flakes, chromic
acid and glycol,etc. The duly cleaned components are dipped into it
and dranning and/or spinning remove any excess sol for catina
components, are then healed to about 300c in an oven in a closely
controlled amosphere. The hexavalent chromium gets reduced to
trivalent chromium, i e., an insoluble amorphous oxide. It acts as
a binder for the many overlapping flakes of zinc and aluminium to
form a film. On same time the chromic acid in the sol also reacts
with the substrate forming a chemical bond providing a strong
adhesion. This corrosion prevention mechanism of the film comes
from the controlled galvanic protection of zinc flakes in the
presence of intergral chromate passivation of each and every flake.
It can be applied in auto parts like bolts, bolts with captive
washers, nuts, engine studs, foundation bolts, washers, clips, coil
springs, brackets, connectors, tapping screws, hose clamps, brake
discs exhaust pipes, engine compartment components, specially under
body components and many marine engine component

