This historic conversion coating technique immerses ferrous metals in a heated, dilute phosphoric acid bath saturated with iron or zinc. The chemical reaction converts the surface of the metal into an insoluble, crystalline phosphate layer that resists rusting. It serves primarily as a porous substrate that absorbs and holds protective oils, waxes, or paints much better than bare steel.
The specs on this restoration job require us to Coslettize the trigger assemblies before applying the final oil finish.
This was one of the earliest commercial phosphating processes, serving as the direct predecessor to Parkerizing.
Also heard as
- Parkerize
- phosphate
Related terms
Bonderize
To treat a steel surface with a phosphate conversion coating to improve paint adhesion and corrosion resistance.
Bonderization
A surface treatment that converts a steel surface into a layer of insoluble zinc or manganese phosphate.
Corrosion inhibitor
Chemical added in small doses to a fluid to slow corrosion of the metal it touches.