Chemical Conversion Coating / Chem Film
Surface protection for aluminum and aluminum alloys used in aerospace, industrial, commercial, and manufacturing applications.
Chemical conversion coating, commonly referred to as Chem Film or Alodine, is a surface treatment primarily applied to aluminum and aluminum alloys to provide corrosion protection, improve paint adhesion, and preserve key functional properties of the part surface.
The coating is formed through a controlled chemical reaction on the aluminum surface, creating a thin protective layer without significantly changing part dimensions. Depending on the drawing, purchase order, or customer specification, the process may be applied in different types and classes.
At PAIMEX, Chem Film processing is performed with a strong focus on process control, traceability, documentation, and customer requirements. Each order is reviewed according to the applicable specification, part condition, and approved processing scope.
Key Benefits of Chem Film
- Corrosion protection: helps protect aluminum and aluminum alloys in demanding environments.
- Paint adhesion: supports improved bonding for subsequent paint, primer, or coating systems.
- Thin protective coating: provides surface protection while helping maintain dimensional requirements.
- Functional performance: suitable for applications requiring corrosion protection and, in some cases, controlled electrical conductivity.
- Versatility: widely used in aerospace, industrial, commercial, and general manufacturing aluminum components.
Applicable Specifications
In the aerospace and industrial markets, this process is commonly requested using both current and legacy terminology, including MIL-DTL-5541, MIL-C-5541, Chem Film, and Alodine. PAIMEX reviews each request based on the customer drawing, purchase order, and applicable specification.
| Specification | Process | Application |
|---|---|---|
| MIL-DTL-5541 |
Chemical Conversion Coating / Chem Film Type I & Type II Class 1A & Class 3 |
Specification used for chemical conversion coatings on aluminum and aluminum alloys, applied according to customer drawing, purchase order, and specification requirements. |
| MIL-C-5541 |
Chemical Conversion Coating / Chem Film Class 1A & Class 3 |
Legacy designation still commonly referenced in drawings, purchase orders, and customer documentation. |
Note: The applicable revision, type, class, and acceptance requirements are determined by the customer drawing, purchase order, and provided specification.
How PAIMEX Processes Chem Film
At PAIMEX, Chem Film is processed with attention to the technical requirements of each part, the applicable specification, and any special conditions defined by the customer.
When required, our team reviews material type, critical areas, surfaces that must not be processed, masking requirements, requested class, and documentation needed for release.
Our approach is built around reliability, process discipline, attention to detail, and documentation control.This supports the quality expectations of aerospace, industrial, commercial, and general manufacturing customers that require reliable surface finishing and documented process control.
Common Chem Film Classes
Class 1A
Typically used when enhanced corrosion protection is required and/or when the coating will support paint adhesion on aluminum and aluminum alloys.
Class 3
Typically used when corrosion protection is required while maintaining low electrical resistance on the part surface.
Helpful Information for Quotation
To begin a Chem Film quotation request, you may start by sharing general project information such as the type of part, material, estimated quantity, and any known process or specification requirements.
PAIMEX can review this initial information to provide guidance, determine whether the process may be applicable, and identify what additional details may be needed for a formal quotation.
When available, the following information can help speed up the review process:
- Part material and general description.
- Estimated quantity of parts.
- Requested specification, if known.
- Required class, such as Class 1A or Class 3, if specified.
- Critical areas, masking needs, or surfaces that should not be processed.
- Drawing or technical print, when available and appropriate.
- Any special quality, packaging, or documentation requirements.
If confidential drawings or proprietary technical information are required for review, PAIMEX can coordinate an NDA or confidentiality agreement when appropriate.
Need a Chem Film Estimate or Quote?
Contact PAIMEX with your general project information. Our team can help review the requirements and guide you through the next steps.
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