Optimum effectiveness of high performance protective coatings is highly dependent on the preparation of the surface prior to application of the coating formulation. Superior results are achieved when the items to be coated are first degreased (using, preferably, conventional alkaline degreasing – although solvent based processes can also be used) and then blasted with an abrasive such as silica, steel grit, or alumina to achieve a surface profile that provides optimum performance and adhesion. In general, the best performance is achieved when the surface preparation is a white metal blast.
Environmental friendly Alkaline or Solvent base oil cleaning is recommended to use, It is applicable to all metal parts. Good oil cleaning is also enough as a pre-treatment for some parts. No acid cleaning for parts having 32 HRC or higher hardness and spring steel to avoid hydrogen embrittlement.
For high strength steels (10.9 grade and above or hardness >32 HRC), Shot blasting is preferred, since Phosphate treatment may lead to Hydrogen Embrittlement, so it is not recommended for spring steel and high strength steel.
Zinc Al Flakes and Organic Coating products can be applied with non Electrolytically applied Dip Spin coating techniques as per ISO 10683 for mass produced hardware parts and by spray application with or without electrostatic for larger metal parts
Dip spin coating process
Whereby product is placed in a mesh basket, submerged in coating solution and spun to remove the excess coating. The temperature and viscosity of the coating, immersion time, spin direction and velocities and the cure method are among the variables that allow users to customize a process recipe and achieve precise, highly repeatable results.
Spray coating process
The coatings can be applied by Spray application techniques which are known in finishing industry. To have more efficiency and economical coating results HVLP and other technological improved systems are more useful compare to older equipments and application techniques.
The coated parts need to cure for polymerization and cross linking of added polymers before the coating is functional. The SST results and other chemical related properties vary if the baking cycle is not being performed properly.