What is electrophoretic coating?
E-coating uses an electrical potential to attract charged paint particles to the prepared component. The process includes pretreatment, deposition, rinsing and curing. It is an organic paint coating rather than metallic electroplating, and coverage depends on bath access, electrical conditions and drainage.
Key specifications
Process references and example callouts are identified below. CHIHENG confirms the accepted material, dimensions and treatment requirements in the part quotation.
| Parameter | Reference / what to specify |
|---|---|
| Materials | Conductive metal compatible with the pretreatment and cure cycle. |
| Film thickness | Specify dry-film thickness in µm from the selected resin data sheet; there is no universal range. |
| Tolerance | Include coating build in final fits and identify features to protect. |
| Colour / exposure | Choose resin and colour for the service environment; an outdoor topcoat may be needed. |
| Geometry | Review openings for solution entry, air escape and drainage. |
| Size / curing | Confirm rack envelope, contact locations and allowable component temperature from CAD. |
Technical references: PPG: e-coating process · Valmont e-coating process
Applications
Automotive equipment
Metal brackets and formed components with recessed surfaces.
Industrial equipment
Housings and frames with reviewed drainage paths.
Coating systems
Components with an e-coat primer beneath a compatible topcoat.
Working with CHIHENG
A direct conversation with our team, from your first drawing to delivery.
A reply within 24 hours
Send us your drawing and questions. Our team will reply within 24 hours and help you work out the next step.
An experienced engineering team
Talk through materials, tolerances and finishing with engineers who understand how your part will be made.
Machining equipment
We use our machining equipment and practical manufacturing experience to turn your drawings into finished parts.
Competitive worldwide shipping
We offer competitive shipping solutions for customers around the world, with options to suit your destination and delivery schedule.
Process steps
- Select pretreatment, resin, dry-film requirement and cure specification.
- Rack, clean and pretreat the part; confirm contact areas and drainage.
- Immerse the part, deposit the paint electrically and rinse away residual emulsion.
- Cure to the resin data and inspect required coverage, thickness and appearance.
Electrophoretic coating vs Powder Coating
| Comparison point | Electrophoretic coating | Powder Coating |
|---|---|---|
| Application | Immersion and electrical deposition of paint | Application of dry powder before curing |
| Recesses | Bath access, air escape and electrical conditions govern coverage | Spray access and electrostatic effects govern coverage |
| Film requirement | Resin-specific dry-film target | Powder-specific target; not interchangeable with e-coat |
| Design review | Drainage, racking, masking and cure | Spray access, racking, masking and cure |
Preparing a part for e-coating
- Include the material, coating specification and any areas that need masking.
- Show openings in hollow parts so we can review venting, drainage and electrical contact points.
- Tell us whether the part will be used outdoors. The coating system needs to suit the actual exposure.
FAQ
Does e-coat guarantee coverage in every recess?
Coverage depends on the geometry and process conditions. Mark internal areas that matter and provide a section view where access or drainage is unclear. The required dry-film value and acceptance locations come from the actual coating system. A generic description is not a complete specification for the finished component.
Is e-coat the same as powder coating?
No. E-coat is deposited from a bath using an electrical process; powder coating applies a dry powder that is then cured. Specify the required system. Include sunlight, moisture and chemical exposure when selecting the resin and any topcoat. An e-coat primer does not automatically establish a complete outdoor coating system.
What should I include for an e-coat quotation?
Send the drawing, material, quantity, coating specification and surfaces requiring protection. Add any curing restrictions and required records. The rack orientation and openings need drawing review. A hollow part must be able to admit the bath, release air, rinse and drain as required.
What e-coat film thickness should I specify?
Use the selected resin manufacturer’s technical data and the application specification to define dry-film thickness in µm. A value used for one e-coat product should not be copied to another without review. Identify significant surfaces and any later topcoat so both local coverage and total film build are part of the quotation.
Does e-coating cover every internal surface?
Immersion can make e-coating useful in recesses that are difficult to spray, but it does not guarantee coverage in every cavity. Bath access, trapped air, electrical conditions and drainage affect the result. Provide the complete geometry and identify required internal coverage so treatment and inspection can be reviewed before production.
