Overview
EN ISO 22553-2:2020 - Paints and varnishes - Electro-deposition coatings - Part 2: Throwing power (ISO 22553-2:2019) specifies laboratory methods to determine the throwing power of electro-deposition (e-coat) materials. Throwing power describes the ability of an electro-deposited coating to reach and build film thickness in cavities and recessed areas - a key property for corrosion protection on complex parts used in automotive and general industry.
Key topics and technical requirements
- Scope and purpose
- Defines two test methods for throwing power: Method A (single‑chamber) and Method B (multiple‑chamber).
- Applicable to electro-deposition coatings for automotive and other industrial applications (chillers, radiators, consumer products, aerospace, agriculture).
- Test principle
- Coat specially prepared test specimens, stove the deposit, and measure dry-film thickness at defined locations to evaluate penetration into cavities.
- Apparatus and materials
- Laboratory deposition system with tank recirculation and DC voltage, electrodes (anode/cathode), controlled bath temperature and stirring.
- Film thickness measuring device (maximum permissible error 0.1 µm), thermometer (0.1 °C), timer and ruler.
- Example panel dimensions: approximately 300 mm × 105 mm × 0.75 mm.
- Method A (single-chamber) - described apparatus setup, specimen mounting (spacers/rack), immersion depth (~280 mm) and minimum tank clearance (~30 mm), bath stirring (e.g., paddle diameter ≥50 mm at 500 min⁻¹), voltage selection to obtain nominal outside film thickness, rinse and stove procedure.
- Method B (multiple-chamber) - alternative multi-chamber specimen system (details in the standard).
- Measurement, evaluation and precision
- Dry-film thickness measured at specified distances or points; the standard includes precision information and requirements for a test report.
- Normative references
Applications and who uses this standard
- Coating formulators and R&D - evaluate and optimize throwing power of cathodic and anodic e-coat formulations.
- Quality control and test laboratories - routine assessment of batch-to-batch consistency and specification compliance.
- Automotive OEMs and tier suppliers - validate corrosion-protection performance on complex body-in-white geometry.
- Specification writers and procurement - include objective test methods in procurement and acceptance criteria.
- Regulatory and certification bodies - use a harmonized method for comparative testing.
Related standards
EN ISO 22553-2:2020 is essential for anyone needing standardized, reproducible measurement of e‑coat penetration (throwing power) to ensure reliable corrosion protection on complex parts.