Surface Preparation
The Science of Cleaning
Proper surface preparation is the critical first step to achieving a high-quality paint finish, but experience shows it is rarely easy. Contaminants, residues, and invisible films can all interfere with adhesion, durability, and appearance. Carbit helps customers overcome these challenges by focusing on two essential principles:
-
Surface Area – Increasing the available surface area improves coating adhesion and long-term performance.
-
Surface Tension – Controlling surface energy ensures coatings flow, level, and bond consistently.
By combining proven cleaning methods with Carbit’s specialized products, we deliver reliable solutions that remove hidden barriers to adhesion. The result is a cleaner, more uniform substrate—ready for coatings that perform and last.
Cleaning and degreasing by dipping parts.
Mechanical Adhesion
The size of the contact area between the paint and the substrate, i.e., surface area, may not be the same. We know that sometimes it is necessary to sand a surface for paint to adhere, but we may not understand that by sanding, we are increasing the surface area of contact between the paint and substrate. This is critical because paint adheres mechanically, not chemically; the bond between the materials increases as the surface area increases.
The photo to the right is a 330x magnification of unpainted cast iron, which illustrates the increased surface area. The average size of molecules in a polymer 0.5 - 2.0 microns, much smaller than the size of the surface area shown in the photograph.
330x magnification of unpainted cast iron.
Surface Tension & Adhesion
Surface area alone, however, may not provide the adhesion required if the surface repels the paint, like water beads up on wax. When water beads, the water molecules are more attracted to each other than to the substrate, like water beads on a freshly waxed car. Differences in surface tension can explain why paint bonds to some materials and not to others, and why just increasing the surface area will not prevent the problem.
Water beading indicates poor surface wetting.
Adhesion Additives
Manufactured products often contain different materials when assembled. Some areas may be made of aluminum, steel, or even rubber, and the different surface areas and their responses to surface tension in the paint may require an adhesion additive, either added to the paint or applied to the surface to achieve adhesion to all types of material. Carbit helps analyze and solve problems by focusing on the manufacturing process:
- Types of material used
- The interplay between the surface area and the surface tension of the materials
- And process requirements - cleaning, pre-treatments, coating recommendations
Adhesion is measured by pulling glued dollies off a painted substrate (ASTM D4541).
Carbit Supplies and Serves Industrial Paint Lines:
- Custom Coatings: Specs, design, formulation, manufacturing
- Process Improvement: Consulting for paint lines
- Paint Line Support: Audits and painter training
- Lab Services: Testing and reporting, plus surface prep, cleaners, and inhibitors
- Technical Field Reps: Training, audits, lab coordination
- Lab Team: Testing, custom formulations, QC, and color matching
- Customer Service & Production: On-time delivery
- Managers & Teams: Continuous improvement and relationship development
Consult Our Experts
Have Questions?We design and manufacture environmentally friendly liquid coatings tailored to your finishing process and performance requirements. Our Technical Service Team manages your project from start to finish, addressing immediate needs while also focusing on your long-term goals. We demonstrate how our products align with your application and performance standards, then provide on-site training and ongoing support.
Need immediate assistance? Call us at
(312) 280-2300