What Is Powder Coating?

Powder coating is a dry finishing process where finely ground particles of pigment and resin are electrostatically charged and sprayed onto a grounded metal part. The part is then baked in an oven at 350–450°F (175–230°C), melting the powder into a smooth, durable, uniform film.

Think of it as painting without the liquid. No solvents, no drips, no runs. The result is a finish that’s tougher than most wet paints and available in virtually any color, texture, or gloss level.

How It Works

1. Surface Preparation

This is where powder coating succeeds or fails. The substrate must be clean, dry, and free of oil, rust, mill scale, and old coatings. Common prep methods:

• Sandblasting / media blasting — removes rust, scale, and old paint. Creates a surface profile for adhesion.
• Chemical pretreatment — iron phosphate (mild steel), zinc phosphate (high-performance), or chromate conversion (aluminum).
• Outgassing — castings and hot-dip galvanized parts trap gas that causes pinholes. A pre-bake at coating temperature drives gas out before powder application.

2. Application

A spray gun charges the powder particles (typically 60–100 kV). The grounded part attracts the charged powder, which clings electrostatically. Reclaimed overspray can be recycled — powder coating wastes very little material (95–98% transfer efficiency with reclaim).

3. Curing

The coated part enters a convection oven. The powder melts, flows, and chemically cross-links into a continuous film. Cure schedules vary by powder chemistry:

Thickness

Standard powder coating thickness is 2–4 mils (50–100 μm). Thicker coats are possible but add cost and can fill fine features. Compared to wet paint:

• Wet paint: typically 1–2 mils per coat, multiple coats needed
• Powder coat: 2–4 mils in one application
• E-coat: 0.6–1.2 mils (thinner, more uniform)

Colors and Textures

Powder coating is available in:

• RAL and Pantone color matching — any color you want
• Gloss levels — high gloss, semi-gloss, satin, matte, flat
• Textures — smooth, wrinkle, sand, hammer, leather
• Metallic and sparkle effects — bonded metallics, candy coats
• Clear coats — over bare metal or as a topcoat

When to Specify Powder Coating

• Steel or aluminum parts that need color and corrosion protection
• Indoor or outdoor use (choose the right chemistry — polyester for outdoor)
• Parts that can withstand 350–450°F cure temperatures
• Batch sizes from 1 to 100,000+
• When you want consistency — powder is more uniform than spray paint

When NOT to Use Powder Coating

• Tight tolerances — 2–4 mil buildup matters on precision fits. Mask critical surfaces.
• Rubber/plastic components — can’t survive the cure oven. Remove before coating.
• Very large parts — must fit in the oven. Some shops have walk-in ovens (8–12 ft), but there are limits.
• Touch-up — can’t touch up powder coat in the field like wet paint. Damaged areas need strip and recoat.
• Thin films needed — if you need less than 1 mil, use e-coat or wet paint.

Cost

Powder coating typically costs $25–150+ per part depending on size, prep required, and color. Simple parts (brackets, panels) are cheap. Complex geometry with masking is more. Specialty colors and textures carry a premium over standard stock colors.

It’s almost always cheaper than wet paint for the same durability level, because there’s no multi-coat build-up, no flash time between coats, and no VOC compliance costs.

Specifications

• ASTM B117 — Salt spray (fog) testing. 500–1000+ hours typical for quality powder.
• ASTM D3359 — Cross-hatch adhesion test.
• AAMA 2603/2604/2605 — Architectural coatings specs. 2605 is the gold standard (10-year Florida exposure).
• GSA-P-FP — Federal spec for powder coating.

Need parts powder coated? Get a quote — we work with multiple coating shops across DFW for fast turnaround.