Powder Coating 101
Powder coating is a finishing process used to create a durable, protective, and visually consistent coating on metal surfaces. Unlike traditional wet paint, which is applied as a liquid, powder coating uses a dry, finely ground powder that is electrically charged and bonded to the metal through heat. The result is a finish that is thicker, stronger, and more resistant to chipping, corrosion, chemicals, and weather exposure.
The process can be broken into four critical stages:
Surface Preparation
The quality and longevity of a powder coated finish is determined by how well the metal is cleaned and prepped. Any contamination — oils, rust, mill scale, dirt, or old paint — will prevent the coating from bonding correctly.
Preparation typically includes:
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Degreasing/Chemical Cleaning: Removes oils, machining residue, and handling contamination.
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Media Blasting or Sandblasting: Abrasive material is propelled at high speed to remove rust, scale, and old coatings while also etching the surface to create a profile that improves adhesion.
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Rinse & Dry: Ensures no cleaning residue remains.
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Pretreatment (Phosphate or Conversion Coatings): Adds corrosion resistance and enhances coating bond strength.
If prep is rushed or skipped, the coating will fail.
This is where cheap coating jobs cut corners. APX doesn't cut corners, our jobs are always quality.
Powder Application, or Electrostatic Charging
Once the metal is clean, the powder is applied using a spray gun that gives the powder particles a positive electrical charge. The part being coated is grounded, giving it a negative charge.
Opposites attract — so the powder is drawn to the metal surface and clings evenly.
Key advantages of electrostatic application:
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Even coating thickness, even on complex shapes
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Reduced overspray waste compared to wet paint
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Smooth, controlled surface appearance
The part now has a uniform layer of dry powder stuck to it — it looks fuzzy and matte at this stage.
Curing in a Controlled Heat Oven
After coating, the part is moved into an oven where the powder melts, flows, and chemically bonds to the surface.
This step turns the powder into a continuous protective coating.
Typical curing involves:
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Temperature: ~350°F to 450°F (176°C to 232°C), depending on powder chemistry
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Time: 10–25 minutes at temperature
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Monitoring: Even heating is critical for proper film formation
During curing:
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The powder melts into a gel-like layer
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It crosslinks into a solid, durable finish
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The surface becomes smooth, uniform, and hardened
When done correctly, the coating is bonded molecularly to the metal.
Cooling and Final Inspection
Once the curing cycle is complete, the part is removed and allowed to cool. The finish will harden into a tough, resilient surface that is:
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Chip resistant
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Corrosion resistant
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UV & weather resistant
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Chemical resistant
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Smoother and thicker than paint
APX Coatings will also inspect:
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Film thickness
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Color uniformity
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Edge coverage (common failure point)
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Surface smoothness / texture consistency
APX Powder Coatings
When powder coating is done correctly, it delivers a finish that looks better, performs longer, and protects metal against the elements for years to come. The difference comes down to proper surface preparation, controlled application, and precise curing — not shortcuts. That’s the standard we work to on every project, whether it’s a one-off part or a full production run. If you’re looking for a finish that’s durable, consistent, and built to last, powder coating is the clear choice — and we’re here to do it the right way.
Contact APX for Powder Coating
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