Yes. Rust inhibitors can be used effectively in enclosed spaces, but the type of inhibitor matters. Furthermore, traditional rust inhibitors that rely on direct contact can be difficult to apply in tight, sealed, or hard-to-reach areas. As a result, in these situations, vapor corrosion inhibitor (VCI) technology offers a reliable and proven solution.
Why contact rust inhibitors can be challenging in enclosed areas
Many liquid rust inhibitors require full surface access to ensure proper coverage. In enclosed spaces, such as internal cavities, electrical enclosures, or complex assemblies, applying these products evenly can be time-consuming and inconsistent. As a result, missed areas may remain unprotected, increasing the risk of corrosion over time.
This is where VCI rust protection becomes especially valuable.
How VCI rust inhibitors protect enclosed spaces
VCI rust inhibitors for enclosed spaces work by releasing protective molecules into the airspace, which diffuse throughout the enclosure and bond to metal surfaces, including uncoated or hard-to-reach areas. As a result, this vapor-phase protection allows corrosion inhibitors to reach internal cavities, hidden surfaces, and complex geometries that are difficult to protect using traditional, contact-only methods.
It is important to distinguish between different types of VCI-based solutions. VCI rust inhibitor liquids provide dual protection by forming a thin protective film on the metal surface while also releasing corrosion-inhibiting vapors into the surrounding air. These products are ideal when both surface protection and vapor-phase coverage are required in enclosed or hard-to-access areas.
By contrast, VCI emitters and diffusers deliver purely VCI corrosion protection. Furthermore, they release corrosion-inhibiting vapors without leaving a coating on the metal surface, making them well-suited for applications where clean, dry, and ready-to-use components are required upon removal from the enclosure.
This makes VCI technology ideal for protecting complex assemblies, internal cavities, toolboxes, control panels, and other enclosed areas where traditional application methods are impractical. In addition to VCI emitters, ZERUST® also provides VCI packaging solutions, such as bags, films,
and papers, which create a sealed environment to ensure consistent, corrosion-free storage and shipment of metal parts.
Applications for rust protection in hard-to-reach areas
VCI-based solutions are commonly used to protect:
- Internal cavities and void spaces
- Toolboxes and maintenance kits
- Electrical and control panels
- Gear housings and mechanical assemblies
- Spare parts stored in sealed containers
For long-term storage or shipment, VCI packaging films and papers create a sealed environment that maintains consistent corrosion protection throughout the enclosure.
RP Oils or VCIs. Which protection method is best?
Learn the key differences between RP oils and VCI corrosion protection methods and find the best solution for your application.
Combining VCI packaging with other rust inhibitors
In many applications, the most effective approach is a layered strategy. VCI rust inhibitors for enclosed areas can be used alongside compatible liquid rust inhibitors to provide both immediate and long-term protection.
This approach provides effective protection for complex assemblies, multimetal components, and high-humidity environments where corrosion risks are higher.
Learn how ZERUST® rust preventative oil protected metal components from corrosion caused by uncontrolled climate conditions at a manufacturing facility.
Learn more about ZERUST® corrosion protection solutions
To explore the full range of options for protecting enclosed and hard-to-reach metal surfaces, we recommend reviewing the following resources:
| ZERUST® Corrosion Inhibitor Liquids, Additives, and Rust Removers Brochure Learn how liquid and water-based rust inhibitors can complement VCI technology in challenging environments.  |
ZERUST® VCI Packaging Film and VCI Kraft Paper Series Brochure
Discover how VCI films and papers create sealed, corrosion-free environments for storage and shipment.
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ZERUST® Vapor Capsules and VCI Diffusers Series Brochure
See how VCI emitters provide targeted, contactless rust protection inside enclosures and confined spaces.
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Axxanol™ 33 is a rust preventative oil that forms a light oily film, providing powerful corrosion protection against aggressive environments such as salt air and humidity.
Axxanol™ 34CD is a solvent-based coating that forms a very light, oily, near dry-to-touch rust preventative film that provides powerful corrosion protection against aggressive environments.
Axxanol™ A35CD-32 is a solvent-based, non-staining rust preventative that forms a clear, thin, near dry-to-touch RP film. As a result, it provides powerful corrosion protection against aggressive environments, such as salt air and humidity.
Axxanol™ Spray-G is a sprayable rust preventative grease that provides the protection of a grease in the convenience of a sprayable form. It’s designed to protect metal parts, equipment, and assemblies during long-term indoor and outdoor storage and challenging overseas shipping applications where a removable coating is essential.
Axxanol™ Z-Maxx Anti-Corrosion Grease Series consists of two products, Axxanol™ Z-Maxx and Z-Maxx LV. Z-Maxx is a thick NLGI 2 grease and is also offered as a lower viscosity (LV) NLGI 0 grease that is designed for spreadability and light lubrication properties.
Axxatec™ 30C is a water-based rust Inhibitor designed to provide short-term indoor storage and in-transit protection. In addition to the corrosion protection offered, Axxatec™ 30C may also be used as a light-duty cleaner-rust preventative combination product.
Axxatec™ 80C is a water-based liquid concentrate rust preventative designed to provide long-lasting protection during indoor storage, shipping, and assembly.
AxxaCoat™ 90B HFS is a sprayable high-flash outdoor rust preventative coating designed to protect metal parts and assemblies during long-term indoor and outdoor storage and challenging overseas shipping applications.
