Can powder coating hide metal surface imperfections?

There are lots of advantages to powder coating; the electrostatic process is known for providing a cost-effective and durable finish. It is also a more sustainable process than wet paint, as it uses less water and fewer chemicals. But a question we are often asked is:

Can powder coating cover scratches or surface imperfections on metal?

Powder coating can mask minor surface finish irregularities to some extent. However, more severe defects, like oil contaminations, cutting fluids, scratches, pinholes, flaking/chipping, and uneven corners, can not be eliminated completely, impacting coating performance.

Aluminium test coupons with replicated surface defects before the powder coating process

For one of our clients, we replicated some typical metal surface defects on their parts on  ‘Aluminium test coupons’ to fast-track the process of determining if surface defects, such as oil contamination and deep scratches, are covered by powder coating. This enabled them to design a finishing spec for their machinists.

For this purpose, we used four aluminium test coupons to test the powder coating process over surface defects.

Coupon A - A defect-free, benchmark piece that replicates an ideal part before the powder coating process begins.

Coupon A is kept to compare coupons B, C, and D, which have surface defects like deep surface scratches, shallow scratches, and oil contamination, respectively.

The result

Powder coating will not hide deep existing surface imperfections, which are easily visible. The use of fine-textured powder, as selected by our customer for their project, has a better chance of covering small scratches in the metal as compared to gloss or matte finish powders. Nonetheless, as shown below, it cannot cover all defects.

Powder-coated Aluminium test coupons

*For this project, fine-textured powder was used as per the customer’s requirement.

Coupon B - The powder coating does not cover the scratches; instead, it follows the profile of the damage without filling it in. This can be easily seen and felt on the metal surface.

Coupon C - More likely to fill in the scratches, but witness marks are visible.

Coupon D - A shadow in the powder coating surface can be seen, and the powder has not adhered to the surface, resulting in failure of the coating. The coating is likely to flake off and fail its purpose.

Powdertech Surface Science, Bicester.

Our customers rely on us to ensure the coating process runs more smoothly during production with fewer delays. At Powdertech, we stay closely involved at every stage to prevent delays, costly reworks, and production downtime, as early detection of surface defects ensures the coating performs as per the spec requirements.

Starting a new project?

Check out our Design your finish at the start to save production time and money article and download a tailored checklist before you begin the process of coating as per your component and its end use.

By getting it right early, you can avoid surface defects mid-production, save cost and time, and achieve your desired surface finish right the first time! 

Checklist to achieve your desired surface finish.

Why choose Powdertech?

Getting to know you and your products is at the heart of what we do. Through building a close working relationship with you, we can be responsive to your business needs – helping you to keep the promises you made to your customers.

We use high-performance powders and the latest equipment to ensure a consistent finish. We regularly invest in new equipment and facilities. Your metal will be pre-treated and coated to an exceptionally high standard, and we go beyond that - our expertise extends to developing new pre-treatments and powder coatings for unique applications. 

If you are looking for a dependable powder coating partner who cares about your business outcomes, you are in the right place. Get in touch to discuss your powder coating requirements - because getting it right early means fewer problems later.