Bonding strength. Molecular attraction to the surface to which a substance is applied. A condition where one material is attached to another by means of surface attraction. Adhesion is affected by the condition of the surface to be coated, by closeness of contact, and molecular forces. The surface being coated should allow a certain amount of penetration, be chemically clean, be hard, not too smooth, and non-porous, to achieve good adhesion.
Sandblasting these steel brackets with 100 grit Garnet Sand or Aluminum Oxide helps provide an important mechanical bond between the coating and the substrate.