ISO 9001/ IATF 16949 Certified Sheet Metal Manufacturer

E-Coating Services for Metal Parts

E-Coat / ED Coating for Uniform Corrosion Protection

SR MFG provides managed e-coating / ED coating support for custom metal parts and fabricated assemblies. E-coat is ideal for parts that require uniform film coverage, corrosion protection, and coating access into cavities, seams, and internal corners.

We support coating thickness, adhesion, salt spray verification, and inspection documentation based on project requirements. Typical e-coat film thickness is about 12.5–30 μm, with project-specific targets available.

Uniform Film Coverage

Covers cavities, seams, and internal corners more evenly than many spray-only processes.

Corrosion Protection

Supports salt spray, adhesion, and film thickness verification when required.

Managed Quality Documentation

Inspection records and test reports can be arranged based on project requirements.

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Upload your drawings for engineering review.

What Is E-Coating?

E-coating, also called electrophoretic coating or ED coating, is a water-based electrodeposition process. A conductive metal part is immersed in an e-coat bath, and under a DC electric field, charged resin and pigment particles migrate to the metal surface and form a uniform coating film.

Because the coating is deposited electrically, e-coat can reach cavities, seams, recessed areas, inside corners, and channels more effectively than many spray-only processes. After rinsing, the coated part is oven-cured to create a dense, consistent film with strong corrosion protection.

E-coating is widely used as a corrosion-protection primer or functional coating for automotive parts, enclosures, brackets, frames, and complex fabricated metal components.

Eight 1.5mm anodized aluminum sheet panels displaying a range of dye colors from natural silver through gold, bronze, black, blue, red, and green

Key Process Principle

E-coating combines three key elements:

Water-based
coating bath

→

DC electric
field

→

Oven curing
after deposition

This allows the coating film to build evenly on conductive metal surfaces, including areas that are difficult to reach with conventional spray coating.

Why It Works Well for Complex Parts

E-coat has strong throwing power, meaning it can coat recessed and internal areas more consistently. This makes it suitable for parts with:

Internal corners

Brackets and frames

Seams and overlaps

Complex fabricated assemblies

Tubular or boxed structures

Areas where spray access is limited

i

Note: E-coating is mainly suitable for conductive substrates. Non-metal materials usually require conductive pretreatment and project-based validation before e-coating can be considered.

E-Coating vs. Powder Coating vs. Wet Painting: How to Choose

Different finishing processes solve different problems. E-coating is best for uniform corrosion protection and internal coverage, powder coating is strong for durable decorative finishes, and wet painting is more flexible for custom colors, low-volume projects, touch-up work, and special appearance requirements.

E-Coating

Best for:

Uniform corrosion protection, cavities, seams, internal corners, and complex metal geometries.

Typical film thickness:

12.5–30 μm

Main advantages:

Highly uniform film build
Strong cavity and edge coverage
Good corrosion-protection foundation
Suitable for repeatable production

Main limitations:

Color options are usually limited
Substrate must be electrically conductive
Higher setup and process-control requirements

Explore E-Coating Services →

Powder Coating

Best for:

Durable decorative finishes, outdoor equipment, enclosures, brackets, covers, and structural components.

Typical film thickness:

50–125 μm

Main advantages:

Durable and wear-resistant finish
Wide range of colors and textures
Low VOC process
Good appearance and corrosion balance

Main limitations:

Frequent color changes require more cleaning
Film control must be evaluated for precision assemblies
Cure temperature and heat tolerance must be checked

Explore Powder Coating Services →

Wet Painting

Best for:

Custom colors, prototypes, small batches, low-volume production, oversized parts, and special appearance requirements.

Typical film thickness:

Project-specific

Main advantages:

Flexible color matching
Suitable for low-volume and high-mix projects
Compatible with a wider range of substrates
Easier for localized touch-up and repair

Main limitations:

More process control is needed to avoid runs or orange peel
Transfer efficiency is often lower than powder coating
Drying, curing, and environmental control affect finish quality

Explore Metal Spray Painting Services →

Quick Selection Guide

Requirement	Recommended Process	Requirement	Recommended Process
Strong internal cavity coverage	E-Coating	Low-volume / prototype projects	Wet Painting
High corrosion-protection foundation	E-Coating or Powder Coating	Standardized high-volume production	E-Coating or Powder Coating
Durable decorative finish	Powder Coating	Complex fabricated structures	E-Coating + Topcoat System
Wide color and texture options	Powder Coating or Wet Painting	Tight appearance requirements	Powder Coating or Wet Painting
Custom color matching	Wet Painting	Functional primer before topcoat	E-Coating

Practical
Guidance

For high corrosion resistance, complex metal structures, standardized high-volume production, and strict environmental requirements, e-coating or powder coating is usually preferred.
For low-volume, high-mix programs, simple geometries, frequent color changes, or special appearance requirements, wet painting is often the most flexible option.
Many demanding programs use a hybrid system: E-coat primer + powder topcoat.

E-coat primer: strong edge, seam, and cavity coverage.
Powder topcoat: adds color, durability, and weathering performance.
Combined benefit: suitable for EV battery enclosures, premium appliance housings, outdoor equipment, and high-value fabricated assemblies.

The best finishing process depends on material, geometry, thickness target, color requirement, service environment, cosmetic grade, masking areas, inspection standards, and production volume.

Discuss Your Finishing Requirements →

How Does SR MFG Provide “Outsourced E-Coating” Services?

SR MFG helps customers manage e-coating prcjects that need uniform corosion protection, cavity coverage, and controlled deliveryThe actual e-coating is performed by qualified partner facilities.

SR MFG remains your single point of contact for engineering review, masking and racking requirements, quality inspection,documentation, schedule coordination, and final delivery.

Why Work with SR MFG for Outsourced E-Coating?

Single Point of Contact

One supplier manages fabrication, coating communication, inspection, documentation, and delivery.

Engineering Review Before Coating

Masking areas, racking points, threads, mating surfaces, and visible areas are reviewed up front.

Controlled Quality Documentation

Film thickness records, lot traceability, inspection results, and test reports can be arranged as required.

Topcoat Integration

Powder coating or wet painting can be added on top of e-coat when appearance or weathering performance is required.

Standard Managed E-Coating Workflow

1

Drawing & Requirement Review

We review drawings, specs, and coating requirements.

2

Fabrication & Pre-Coating Preparation

Parts are fabricated and prepared for coating.

3

E-Coating Feasibility & Partner Coordination

Feasibility is confirmed and the best partner is selected.

4

Sampling & Validation

Samples are coated and validated to meet requirements.

5

Batch Production & Process Tracking

Production proceeds with process tracking and monitoring.

6

Final Inspection & Documentation

Parts are inspected and documentation is completed.

7

Packing & Delivery

Parts are packed properly and delivered on time.

Who Does What?

SR MFG — Your Single Point of Contact

Reviews drawings, masking areas, and functional surfaces
Coordinates fabrication, partner communication, schedule, and logistics
Defines inspection points and documentation needs
Arranges topcoat integration when needed

E-Coating Partner Facility

Performs pretreatment, electrodeposition, rinsing, and curing
Executes coating per agreed process requirements
Provides process records or test data when required

Best fit for corrosion-resistant primer coating, welded frames, brackets, enclosures, fabricated structures, and projects that need one supplier to manage fabrication, coating, inspection, and delivery.

Send Your Drawings for E-Coating Review →

E-Coatable Parts & Materials We Can Review

SR MFG supports e-coating review for sheet metal parts, stamped components, welded assemblies, and otherconductive metal parts that require corrosion-resistant primer coating, internal coverage, or controlled surface finishing.Final feasibility depends on material conductivity. part geometry. pretreatment compatibility. masking areas, rackingmethod, coating window, and validation requirements.

Fabricated Sheet
Metal Parts

Enclosures and cabinets
Equipment housings
Brackets and mounting plates
Guards, covers, bases, and frames
Welded assemblies and stiffeners

Stamped &
Formed Parts

Pierced parts
Blanked parts
Deep-drawn parts
Reinforcement parts
Clip / snap and guide features

Typical Conductive
Materials

Carbon steel and alloy steel
Hot-dip galvanized steel
Electro-galvanized steel
Aluminum-zinc coated steel
Stainless steel and aluminum

Special substrates can be reviewed case by case.

Best-Fit
Use Cases

Corrosion-resistant primer coating
Complex geometry with internal coverage
Coverage in seams, cavities, and recessed areas
Base coat before powder coating or wet painting
Controlled inspection and documentation

i

E-coating success depends on surface condition, pretreatment quality, drain / vent design, masking strategy, racking position, film thickness target, and post-coating inspection requirements.

Need a feasibility review?

Send Your Drawings for E-Coating Review →

Material & Pretreatment Considerations for E-Coating

E-coating performance depends on substrate condition, pretreatment compatiblity. film thickness target, and validation requirements.
SR MFG works with qualifed partners and applies proven strategies to help ensure adhesion, corrosion resistance consistency. and production stablity.

01

Carbon Steel &
Alloy Steel

Common Substrates

Most widely used materials for e-coat. Cleaning + phosphate pretreatment are typically used to support adhesion and corrosion resistance.

Key Focus

Oil, rust preventive, welding fumes, and mill scale removal
Stable phosphate coating weight control
Blasting / shot blasting for cast iron or porous castings when required

02

Galvanized / Zinc-
Coated Steel

Project-Dependent

Feasible and widely used, but surface condition is critical for consistent adhesion.

Key Focus

Passivation, white rust, oils, and residues control
Matched conversion / pretreatment system for zinc surfaces
Clean / activate when needed for passivation film or white rust

03

Aluminum &
Mixed-Metal Parts

Requires Validation

More sensitive to oxide and conversion coating stability. Pretreatment line compatibility is especially important.

Key Focus

Use aluminum-focused conversion systems when required
Confirm multi-metal compatibility for mixed assemblies
Define key control points and inspection method

04

Film Thickness &
Tolerance Control

Project-Specific

Film thickness target and dimensional control should be defined by project requirements and validated.

Key Focus

Typical thickness: 12.5–30 μm project-dependent
Control single-point variation, overall uniformity, and batch consistency
Pay attention to edge effect and measurement reliability

Key Factors That Influence E-Coat Performance

Surface
Condition

Pretreatment
Quality

Racking & Drain /
Vent Design

Film Thickness
Target

Inspection Method
& Validation

Service Environment
& Requirements

!

Important Note

Final pretreatment route, e-coat system, thickness target, and control limits should be confirmed based on material, geometry, coating system, inspection method, service environment, and customer acceptance criteria.

ADVANCED TECHNICAL NOTE

Film Thickness & Dimensional Tolerance Control

Use this section for tolerance-sensitive or engineering-critical projects where coating build must be defined and controled.

Typical DFT Range

Cathodic e-coat: commonly 18–25 μm
Project-defined window may vary within ~12.5–30 μm
Final target should follow coating system, geometry, and specification

Tolerance-Sensitive Areas

Threads and mating surfaces
Grounding / contact areas
Holes, edges, and assembly interfaces
Masking or thickness limits may be required

Uniformity & Batch Control

Define single-point tolerance where needed
Control within-part film uniformity
Review edge build-up and batch consistency
Prioritize CTQ / critical features

Measurement & Records

Use calibrated DFT measurement equipment
Define inspection points in advance
Keep traceable records and reports when required
Support customer validation requirements

!

Excessive film variation may affect appearance, corrosion resistance, grounding, assembly fit, or dimensional tolerance. Critical surfaces should be defined before production.

Are you ready to get started on your metal fabrication project?

Not sure which material is ideal for your project? Feel free to contact us.Our engineering team will recommend suitable material grades and sheet thicknesses based on strength, weight, corrosion resistance and overall cost.

We’ll provide you with a free quote

Industries & Electrophoretic Coating Applications

SR MFG provides professional electrophoretic coating (e-coating) services for OEM metal components used in industrial equipment, cabinets, brackets, frames, enclosures, and structural assemblies. E-coating delivers uniform, edge-to-edge coverage even on complex geometries and recessed surfaces, making it ideal for parts that demand consistent corrosion protection. We support both prototype finishing and high-volume production across multiple application sectors.

Data Centers & IT Equipment

E-coating for data center components, network infrastructure, and IT hardware, providing uniform, thin-film corrosion protection that reaches every surface, seam, and recess.

Server rack frames & rails
Cable management trays

Cabinet panels & doors
Mounting brackets & plates

Consumer Electronics

Electrophoretic coating for consumer electronics housings, internal brackets, display structures, and precision metal assemblies, delivering consistent film thickness with excellent adhesion and a clean, refined surface finish.

Device housings & covers
Internal support brackets
Display mounting structures

Speaker & audio metal parts
Small precision formed parts

Electrical Equipment

E-coating for electrical enclosures, control cabinets, power distribution units, and industrial electrical components, offering superior corrosion resistance and full coverage on intricate internal surfaces where traditional methods may fall short.

Electrical cabinet enclosures
Control box panels
Terminal mounting plates

DIN rail brackets
Ventilation and access panels

Industrial Equipment

Durable electrophoretic coatings for machinery, automation systems, production equipment, and structural machine assemblies, engineered to deliver long-lasting protection against rust, chemicals, and environmental exposure.

Machine covers & guards
Equipment frames
Conveyor brackets

Sensor mounting plates
Protective panels & shields

New Energy Systems

E-coating solutions for EV charging equipment, battery systems, energy storage cabinets, and power conversion units, providing reliable, uniform corrosion protection rated for demanding indoor and outdoor operating environments.

Battery enclosure parts
Charging station cabinets
Energy storage cabinet panels

Busbar support brackets
Power module housings

Outdoor Equipment

Weather-resistant electrophoretic finishes for outdoor enclosures, equipment covers, BBQ grills, lighting systems, and structural fixtures, engineered for UV stability, moisture protection, and long-term corrosion resistance in harsh outdoor conditions.

Outdoor equipment housings
BBQ grill sheet metal bodies
Protective covers & panels

Mounting brackets
Weather-resistant structural parts

Built for Your Application

Whether you need a single sample or full production volumes, SR MFG ensures consistent coating thickness, complete surface coverage, and reliable delivery for every e-coating project. We offer both cathodic and anodic electrophoretic processes in a range of colors to meet your technical and aesthetic requirements.

Explore Industry Applications

SR MFG E-Coating Product Showcase

Exploded view of EV battery pack assembly showing top cover, bottom tray, side panels, and cell modules

Sheet Metal E-Coating FAQs

What colors are available for e-coat? Are black and gray the most common?

E-coat is available in multiple colors, but black and gray are the dominant choices, accounting for the vast majority of applications (often cited as 90%+ in many industries).

Black: The most common e-coat color, valued for strong corrosion protection and high tolerance to cosmetic variation. Widely used for automotive chassis parts, construction equipment, and consumer electronics components. Available in gloss, semi-gloss, and matte options depending on the system.
Gray: A neutral tone commonly used for industrial components and architectural parts, balancing function and visual compatibility.
Colored e-coat: Custom colors such as white, red, blue, or gold can be developed for differentiated appearance needs (e.g., premium consumer electronics or decorative hardware). These typically require a dedicated colored e-coat system and process tuning.

How do you control thickness or mask critical mating surfaces?

For surfaces that require strict thickness control—or must remain uncoated—we typically use a combination of the following approaches:

Physical masking: High-temperature silicone plugs, ceramic fixtures, or high-temp tape (≥180°C) to mask threaded holes, dowel holes, and precision mating surfaces. For complex contoured surfaces, dedicated masking tooling can be developed to ensure full coverage and prevent lift-off during curing.
Process-based thickness control: Techniques such as staged voltage control (reducing the electric field intensity around critical areas), adjusting rack angles to reduce field exposure, and optimizing deposition time can help keep coating on mating surfaces very low (often targeted around 0–5 μm, when required for fit).
Local insulating pre-treatment: Applying a dedicated insulating primer to critical areas to reduce deposition at the source—useful for standardized parts in long-term production.

Can you provide DFT, adhesion, and salt spray reports?

Yes. Reporting is typically available in two categories:

In-house inspection reports: Film thickness mapping using magnetic induction/eddy-current gauges (typical accuracy around ±1 μm), adhesion tested per cross-hatch (e.g., ISO 2409), and corrosion validation via neutral salt spray (e.g., ASTM B117). Sampling reports can be provided by batch.
Third-party certified reports: Accredited third-party reports (e.g., CNAS/CMA-qualified labs) can be arranged for key metrics such as thickness uniformity (e.g., CV ≤ 10%), adhesion (commonly 0–1 grade targets where specified), and salt spray performance (e.g., 240–1000 hours, as required). Formal reports can be provided after first-article production for project acceptance.

How do you prevent pinholes and blistering on galvanized parts and castings?

For galvanized parts (pinholes):

Use mildly acidic degreasing (pH 5–6) to avoid aggressively attacking the zinc layer and exposing porosity.
Add zirconium conversion after degreasing to seal micro-pores and build a dense conversion layer.
Use pulse-voltage strategies (e.g., a short low-voltage “soft start”) to help release trapped gases at the surface before full deposition.

For castings (blistering):

Shot blast to remove embedded residues, followed by high-pressure washing to remove oils inside pores.
Use phosphate-free ceramic conversion in some cases to reduce bubble risk associated with crystalline porosity.
Add vacuum degassing before e-coat for high-risk castings to pull out trapped gas and reduce expansion-related blistering during bake.

When do you recommend a pre-bake?

A pre-bake is mainly recommended in three scenarios:

Solvent-containing e-coat systems: A low-temperature pre-bake (e.g., 80–100°C for 10–15 minutes) can gently drive off solvents before full cure, reducing bubble/crater risk from rapid evaporation at high temperature.
High-humidity production conditions: In rainy seasons or coastal/high-humidity environments, pre-bake helps remove residual moisture that can interfere with deposition uniformity.
Large, complex structures: For parts over ~2 meters or large castings/sheet metal structures, pre-bake can reduce drag-out (bath carryover), minimize bath loss, and reduce the risk of thickness variation caused by heavy carryover evaporating during cure.

Can you apply powder coating or wet paint over e-coat?

Yes—e-coat can serve as a primer for topcoats, but compatibility must be managed.

Powder coating over e-coat: Improve adhesion with plasma activation or light scuff sanding (e.g., ~200 grit). Keep powder cure temperature compatible with the e-coat substrate (typical reference: 160–180°C for 20–30 minutes, depending on system/PMT). Control total build to avoid fit/tolerance issues (some programs target ≤60 μm total, depending on the part and tolerance stack).
Wet paint over e-coat: Confirm the e-coat is fully cured (e.g., hardness ≥2H, if specified). Use a topcoat compatible with the e-coat chemistry, and remove static dust before spraying to avoid defects such as lifting or fisheyes.

How is quality responsibility defined for outsourced e-coat?

Responsibility is typically defined through a technical agreement that sets clear boundaries:

Incoming part condition: The customer supplies parts that meet agreed cleanliness requirements (e.g., low residual oil, no rust, no deformation). If coating failure is caused by incoming defects, responsibility remains with the customer.
Process execution: The coating partner must follow the confirmed process window. If deviations in voltage, temperature, deposition time, etc. cause out-of-spec thickness, poor adhesion, or failed salt spray results, responsibility rests with the coating partner.
Acceptance criteria: The agreement should define film thickness tolerance, adhesion grade, salt spray duration, and acceptance thresholds. First-article samples serve as the baseline, and third-party reports can be used as the final arbitration method when required.

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E-Coating Services for Metal Parts

Uniform Film Coverage

Corrosion Protection

Managed Quality Documentation

Get a Custom Quote in 12 Hours

What Is E-Coating?

Key Process Principle

Why It Works Well for Complex Parts

E-Coating vs. Powder Coating vs. Wet Painting: How to Choose

E-Coating

Powder Coating

Wet Painting

How Does SR MFG Provide “Outsourced E-Coating” Services?

Single Point of Contact

Engineering Review Before Coating

Controlled Quality Documentation

Topcoat Integration

Drawing & Requirement Review

Fabrication & Pre-Coating Preparation

E-Coating Feasibility & Partner Coordination

Sampling & Validation

Batch Production & Process Tracking

Final Inspection & Documentation

Packing & Delivery

E-Coatable Parts & Materials We Can Review

Fabricated SheetMetal Parts

Stamped &Formed Parts

Typical ConductiveMaterials

Best-FitUse Cases

Material & Pretreatment Considerations for E-Coating

Carbon Steel &Alloy Steel

Galvanized / Zinc-Coated Steel

Aluminum &Mixed-Metal Parts

Film Thickness &Tolerance Control

Key Factors That Influence E-Coat Performance

Important Note

Film Thickness & Dimensional Tolerance Control

Typical DFT Range

Tolerance-Sensitive Areas

Uniformity & Batch Control

Measurement & Records

Are you ready to get started on your metal fabrication project?

Industries & Electrophoretic Coating Applications

Data Centers & IT Equipment

Consumer Electronics

Electrical Equipment

Industrial Equipment

New Energy Systems

Outdoor Equipment

Built for Your Application

SR MFG E-Coating Product Showcase

Sheet Metal E-Coating FAQs​​​​

E-Coating Technical Resources

Quick Links

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Fabricated Sheet
Metal Parts

Stamped &
Formed Parts

Typical Conductive
Materials

Best-Fit
Use Cases

Carbon Steel &
Alloy Steel

Galvanized / Zinc-
Coated Steel

Aluminum &
Mixed-Metal Parts

Film Thickness &
Tolerance Control

Sheet Metal E-Coating FAQs