Powder coating over plated surfaces is often a challenge, and the success of the application depends significantly on the type of plating used. While it's sometimes possible, it's not a guaranteed process for all plated finishes.
As noted in materials from February 1, 2016, "Plated surfaces are always a challenge for adhesion of an organic coating such as powder. There are certain types of plating that powder will not bond with very well."
This highlights the primary difficulty: achieving adequate adhesion between the powder coating and the smooth, dense surface of the plating.
The Adhesion Challenge
Organic coatings like powder rely on proper surface preparation to create a strong bond. Plated surfaces, by their nature, are often designed to be smooth, non-porous, and resistant to corrosion and chemical reactions – properties that can make it difficult for powder to adhere effectively.
- Smoothness: A very smooth plated surface lacks the mechanical profile (surface roughness or 'tooth') needed for powder to physically grip.
- Chemistry: Some plating chemistries may be incompatible with the powder coating process, interfering with curing or bonding.
- Porosity: Unlike raw metal that can be etched or blasted to create microporosity, plating is typically non-porous, limiting chemical or mechanical keying.
Plating Type Matters
The reference explicitly states that certain types of plating will not bond well with powder coating. This means compatibility varies greatly. For example:
- Some common platings like chrome or nickel can be particularly challenging without specialized pre-treatment.
- Other platings might offer better compatibility or respond better to specific preparation methods.
Because compatibility depends on the specific plating, there is no single "yes" or "no" answer that applies universally to all plated surfaces.
Key Considerations for Powder Coating Over Plating
If you are considering powder coating over a plated part, it's crucial to:
- Identify the Plating Type: Know exactly what material the part is plated with.
- Consult with Powder Coating Professionals: Discuss the specific plating type with an experienced powder coater. They can advise on the feasibility and necessary preparation steps.
- Test: Always recommend testing on a sample piece of the specific plated material before committing to a full production run.
Ultimately, while powder coating over plating isn't impossible, it requires careful consideration of the plating type and often necessitates specialized surface preparation techniques to overcome the inherent adhesion challenges.
