Coatings 101

Powder Coating

Powder coating is applied as a free-flowing, dry powder. The main difference between a conventional liquid paint and a powder coating is that the powder coating does not require a solvent to keep the binder and filler parts in a liquid suspension form. The coating is typically applied electrostatically and is then cured under heat to allow it to flow and form a "skin". The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is considered environmentally friendly because it emits near zero VOCs (Volatile Organic Compounds).

Ceramic Coatings

There are 4 basic types of ceramic coatings.

Thermal Barriers

These coatings reduces the ability of heat to escape from the applied part or protect a part from excessive heat. In combustion chambers you want to use the heat generated by combustion to push down on the piston rather than bleed off into surrounding surfaces. These coatings can also provide oil shedding properties.

Thermal Dispersants

Excessive temperature can lead to metal fatigue, boiling fluids damaging metal expansion and more. These coatings allow the metal to transfer heat away 15-20% more efficiently. They are also oil shedding, providing faster drain-back to the oil pan. Use them on any part that is or can be used to provide cooling.

Dry Film Lubricants

Also known as solid film lubricants, these coatings can be applied to any surface that experiences sliding or rotational friction. The interesting property with these coatings is that they are also oil retaining, meaning; they not only provide lubrication by themselves, but also help hold oil to the part for even better lubrication. These coatings may also allow lighter weight oils to be used, thus freeing up horsepower.

Specialty Coatings

These coatings are most commonly used to provide a more attractive appearance to a part. Many of the coatings in this area also provide increased protection against corrosion and are very chemical resistant.

Powder Coating Vs. Ceramic Coating

Powder coatings are applied in thicker films, typically 2-3mils (.002-.003”). Ceramic coatings are based on thin film technologies. Finished thickness is typically 1 mil (.001”). Most ceramic dry film coatings burnish down to a final thickness close to 0 tolerance.

Powder coating will withstand temperatures up to about 300°f before breaking down or losing its effectiveness. A limited number of high temp powder coatings are good up to 1000°f. Ceramic coatings will withstand temperatures in excess of 1600°f with some formulations good beyond 2000°f.

Both powder coating and ceramic coating provide very good corrosion resistance and a high resistance to chemicals. Powder coating is typically a more flexible coating, well suited for parts that will flex or twist like suspension springs.