Understanding ChemFilm
ChemFilm, also called chemical conversion coating or Alodine, provides aluminum with corrosion resistance, improved paint adhesion, and reliable electrical conductivity where required. As a NADCAP accredited leader in aerospace coatings, National Aerospace Processing (NAP) delivers this process with the quality and precision top manufacturers rely on. Our controlled ChemFilm process ensures consistent coverage across complex parts and large production runs without changing dimensions.
What is ChemFilm?
ChemFilm is a thin, protective aluminum coating created through a chemical conversion process that converts the surface of aluminum into a durable, corrosion-resistant layer. The process includes cleaning, activation, conversion, and deionized water rinses on a dedicated line, producing uniform coverage even on complex geometries.
The Benefits of ChemFilm
Protection Against Corrosion
ChemFilm establishes a robust barrier that protects aluminum from moisture, salt sprays, fuels, and operational contaminants — extending service life and reducing maintenance costs across the fleet. Class 1A is specified where maximum corrosion resistance is required (painted or unpainted).
Paint Adhesion
The conversion layer from the ChemFilm process provides an excellent anchor for primers and topcoats, helping reduce chipping, flaking, and underfilm corrosion. This translates to cleaner edges, better coverage on fasteners and flanges, and fewer paint-line rejects.
Aerospace-Grade Quality
Class 3 ChemFilm is widely used on electronic enclosures and bonding/grounding features because it maintains low electrical contact resistance while protecting against corrosion. This combination is crucial for reliable aerospace component performance.
ChemFilm Applications in Aerospace
From wing skins and fuselage panels to fuel system components and electronic enclosures, ChemFilm is the go-to aluminum coating when you need:
- Corrosion protection without altering dimensions
- Strong paint adhesion for lasting finishes
- Low-resistance grounding and bonding (Class 3)
- Consistent, traceable results across OEM, Tier 1, and Tier 2 applications
MIL-DTL-5541 Type 1 Class 1A & Class 3
Traditional hexavalent chromium chemistry (NAP uses Alodine 1200S) for high-reliability aluminum and aluminum alloy applications. Delivers lasting corrosion protection, strong paint adhesion, and broad acceptance for aerospace and critical components. Class 3 ensures reliable electrical continuity where required.
MIL-DTL-5541 Type 2 Class 1A & Class 3
Trivalent, RoHS-compliant chromium (NAP uses Chemeon eTCP) with distinctive color options for visual verification of coverage. Enables environmental compliance, excellent paint adhesion and corrosion resistance, and reliable performance for electronic assemblies (Class 3).
AMS-2473
Frequently specified alongside ChemFilm, AMS-2473 covers chromic acid anodizing (CAA) when an anodic film is required. This process provides enhanced durability, strong corrosion resistance, and an outstanding paint base widely accepted across aerospace applications.
Work with Experts in Aerospace ChemFilm Coatings
National Aerospace Processing delivers NADCAP-accredited ChemFilm services with the precision aerospace manufacturers require. With adherence to NADCAP AC7108/11 for Conversion Coating and a certified aerospace quality system, we ensure consistent, audit-ready results. Contact us today to discuss your next project – our expert team is happy to help you determine the optimal ChemFilm process for your aerospace parts.