E-Coating

E-Coating applies a thin, uniform, corrosion-resistant organic film to conductive parts using an electrically driven immersion paint process, ideal for complex, high-volume metal parts.

Overview

E-Coating is an immersion paint process where electrically charged paint particles deposit onto a grounded, conductive part, forming a thin, uniform organic coating. It excels at coating complex geometries, internal cavities, and sharp edges with consistent film thickness that is difficult to achieve with spray methods. Typical thickness ranges from about 15–35 µm, providing strong corrosion resistance and a controlled base layer for later topcoats.

Use E-Coating when you need durable corrosion protection, consistent coverage on complex metal assemblies, and high-throughput capability. It is common as a primer for powder or liquid topcoats on automotive, appliance, and industrial parts. Tradeoffs: color choices and finish aesthetics are more limited than decorative coatings, line setup costs are significant, and part size is constrained by tank dimensions. Masking, hanging, and rack design matter; poorly designed parts trap solution and drive rework. For medium to very high volumes of conductive parts needing robust corrosion performance and uniform coverage, E-Coating is often one of the most economical options.

Common Materials

  • Mild steel
  • Stainless steel 304
  • Stainless steel 316
  • Aluminum 6061
  • Galvanized steel
  • Ductile iron

Tolerances

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Applications

  • Automotive body and chassis components
  • Agricultural equipment frames and brackets
  • Appliance housings and panels
  • Industrial enclosures and control boxes
  • Furniture and hardware components
  • Fasteners and small stamped parts

When to Choose E-Coating

Choose E-Coating for conductive metal parts that need strong corrosion resistance, uniform coverage on complex geometries, and high-volume, repeatable production. It works well as a primer layer under powder or liquid topcoats and for parts that must withstand outdoor or harsh industrial environments. Best fit is medium to very high production volumes and parts that can be fixtured and drained effectively in immersion tanks.

vs Anodizing

Pick E-Coating instead of anodizing when you need robust organic corrosion protection on steel or mixed-metal assemblies, or when you want a paintable, uniform primer layer. Anodizing is limited primarily to aluminum and magnesium, while E-Coating can handle a wide range of conductive metals and complex welded assemblies in a single line.

vs Powder Coating

Choose E-Coating over powder coating when you need very uniform coverage in tight recesses, internal cavities, and sharp edges, or when E-Coat will serve as a primer before a decorative topcoat. E-Coating lines typically run faster and are more suitable for very high volumes of small to medium parts where film build must be tightly controlled.

vs Chromium Electroplating

Use E-Coating instead of chromium electroplating when corrosion resistance and coverage are more important than a hard, decorative metallic surface. E-Coating is generally lower cost, avoids hexavalent chromium, and coats complex shapes more uniformly, making it better for structural or functional parts rather than purely decorative finishes.

vs Zinc Electroplating

Select E-Coating over zinc plating when you want a thicker organic barrier coating, better edge coverage, and a more uniform appearance across welds and mixed surfaces. E-Coating is often preferred when the part will later be topcoated or when white rust and cosmetic issues from thin zinc layers are a concern.

vs Physical Vapor Deposition (PVD)

Choose E-Coating instead of PVD when your priority is cost-effective bulk corrosion protection rather than ultra-thin, decorative, or high-hardness functional films. E-Coating is better suited for large parts, welded assemblies, and high production volumes where robust coverage and economics matter more than nanometer-scale film control.

Design Considerations

  • Provide drain holes and vent paths so liquid and paint can flow in and out of cavities without trapping solution or causing runs
  • Avoid deep blind pockets, narrow gaps, and nested assemblies that hinder solution flow and lead to thin or uncoated areas
  • Define critical-to-function surfaces and masking requirements clearly on drawings, including any areas that must remain uncoated or within tight dimensional limits
  • Account for coating thickness in stack-ups, especially on threads, press fits, and tight clearances; overspecifying thickness drives rework and masking cost
  • Design robust hanging or racking features (holes, tabs, or edges) that can support the part, ensure good electrical contact, and avoid visible cosmetic areas
  • Specify coating type, color, target thickness range, and corrosion performance standard (e.g., salt spray hours) to help shops quote accurately and choose the correct bath chemistry