How to use ZERUST® VCI Products Correctly

For nearly five decades, manufacturers and OEMs around the world have relied on ZERUST® Vapor Corrosion Inhibitor products to protect metal parts during shipping and storage. However, many users still ask an important question: how to use VCI correctly to achieve the best corrosion protection.

Understanding how to use VCI properly ensures that the corrosion inhibitors can work effectively and protect metal surfaces from rust. When applied correctly, ZERUST® Vapor Corrosion Inhibitor technology creates an invisible protective layer on metal surfaces that stops the electrochemical corrosion process.

The following guidelines explain how to use VCI packaging and protection products correctly so your metal parts remain clean, dry, and corrosion-free throughout storage and transport.

Understand How VCI Protection Works

Before learning how to use VCI packaging, it is important to understand how the technology protects metal.

VCI products release corrosion-inhibiting molecules into the enclosed airspace. These molecules travel through the air and settle on exposed metal surfaces. Once they reach the metal, they form a microscopic protective barrier that blocks moisture, oxygen, and other corrosion-causing contaminants.

VCI products come in many forms, including:

• Poly bags and sheeting
• Kraft paper
• Diffusers and emitters
• Powders and liquids

Regardless of the format, the goal remains the same. The corrosion inhibitor vapors must remain contained inside the packaging environment so they can build a protective atmosphere around the metal parts.

Seal the Packaging Environment to Contain VCI Vapors

One of the most important steps when learning how to use VCI products is ensuring that the protective vapors remain inside the package.

If corrosion inhibitor vapors escape into the surrounding atmosphere, the protection level decreases significantly.

To contain the VCI protection atmosphere:

• Seal VCI bags using heat sealing, cable ties, or tape
• Fully close cartons and containers
• Encapsulate pallet loads using VCI film or shrink wrap
• Avoid leaving large openings in packaging

A properly sealed environment allows the VCI molecules to circulate and continuously protect the metal surfaces inside the package.

Start With Clean and Dry Metal Surfaces

VCI works best on clean, uncontaminated metal surfaces.

In many manufacturing environments, corrosion begins because metal parts are packaged while still contaminated with corrosion-causing residues. Common contamination sources include:

• Chlorides from machining fluids
• Fingerprints and handling residue
• Dirty work surfaces
• Poorly maintained metalworking fluids
• Bacteria or ionic contamination

Before packaging metal parts with VCI, ensure that the components are clean and completely dry.

Even though many ZERUST® Vapor Corrosion Inhibitor chemistries are water-soluble, the inhibitor molecules still require time to deposit on the metal surface. If parts are packaged wet or damp, corrosion may begin before the VCI layer has time to form

Package Metal at Ambient Temperature

Another key factor when learning how to use VCI correctly is temperature control during packaging and unpacking.

Metal parts should always be packaged at ambient room temperature. If hot metal parts are sealed inside packaging, condensation can form inside the package as the air cools. This greenhouse effect introduces moisture that can trigger corrosion.

The same principle applies during unpacking.

For example, parts shipped in a warm warehouse during winter may arrive in a cold environment. Opening the package immediately can cause flash condensation on the metal surface.

To prevent this issue, allow incoming parts to reach room temperature before opening the packaging.

Avoid Contact With Corrosion-Causing Materials

Many packaging systems require additional materials such as boxes, dividers, or pallets. When learning how to use VCI packaging, it is important to consider how these materials interact with the protected metal.

Avoid direct contact between metal parts and materials such as:

• Cardboard
• Non-VCI paper
• Untreated wood

These materials can absorb moisture or release acids that contribute to corrosion.

If dividers or interleaving sheets are required, make sure they allow corrosion inhibitor vapors to reach all metal surfaces. In multi-layer packaging or high part density packaging, additional VCI materials may be required to ensure consistent protection throughout the container.

Use Enough VCI Material for Large or Layered Packaging

In large containers or layered packaging systems, VCI molecules must travel farther to reach every metal surface.

To maintain effective protection:

• Place VCI materials between layers of parts
• Use additional VCI paper or film inside large packages
• Add emitters or diffusers in enclosed containers when necessary

Providing multiple Vapor Corrosion Inhibitor sources ensures that the inhibitor molecules distribute evenly and protect all metal surfaces.

Recycling and Sustainability of ZERUST® VCI Products

ZERUST® VCI poly products can be recycled or disposed of in the same manner as similar LDPE materials used in industrial packaging, and additionally is:

• Recyclable
• Repulpable
• Manufactured from responsibly managed forestry sources

ZERUST® is a registered trademark of Northern Technologies International Corporation (NTIC), the inventor of Vapor Corrosion Inhibitor film and bags. Today, NTIC’s ZERUST® division provides a complete corrosion management system, including Vapor Corrosion Inhibitor packaging, rust preventative coatings, rust removers, cleaning chemicals, and corrosion testing services.

Learn More About How to Use VCI for Corrosion Protection

Understanding how to use VCI correctly is essential for protecting metal parts during storage, shipping, and long-term preservation. Proper sealing, clean parts, temperature control, and correct packaging design all contribute to reliable corrosion protection.

If you want a quick reference, you can also review the complete How to Use ZERUST® VCI guide.

For more information, contact ZERUST® corrosion experts at (763) 225-6600 to discuss the best protection strategy for your application.

Michael Malczewski

Michael Malczewski has been part of the VCI industry for more than 20 years and currently serves as Sales Director at ZERUST®. Based in the greater Chicago area, Michael supports customers throughout the north central United States, helping manufacturers implement corrosion prevention programs that protect valuable assets and improve operational efficiency. With his extensive knowledge of VCI technology and customer-focused approach, he provides tailored solutions across a wide range of industries, making him a trusted partner for long-term corrosion management strategies.

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