Condensation usually occurs due to rapid temperature changes during storage or shipping.
Common causes include:
- Packaging warm parts in a cooler environment
- Moving parts from air-conditioned facilities into humid outdoor air
- Overseas shipment through changing climate zones
- Sealing humid air inside a VCI bag
When warm, moisture-laden air cools, the air can no longer hold the same amount of water vapor. The excess moisture condenses into liquid water on the coldest surface, often the metal part.
This phenomenon is sometimes called container rain during ocean freight shipments.
How Moisture Inside VCI Packaging Affects Corrosion Protection
VCI products do not absorb or displace liquid water. Instead, they interrupt the electrochemical corrosion process in enclosed spaces.
If the moisture inside VCI packaging is limited to light humidity, VCI molecules can still protect the metal surface. However:
- Standing water may cause flash rust
- Trapped corrosive residues can accelerate oxidation
- Heavy condensation can delay VCI layer formation
The key is balance. VCI protects against humidity-driven corrosion, but excessive free water increases corrosion risk.
Best Practices to Prevent Moisture Inside VCI Packaging
Follow these steps to reduce the risk of condensation:
1. Ensure Parts Are Surface Dry
Parts should be visibly dry before sealing. Remove rinse water, machining fluids, and cleaning residues.
2. Control Temperature Before Packaging
Allow parts to cool to ambient temperature before sealing in VCI film or bags.
3. Avoid Sealing Humid Air
Package in a controlled environment when possible. Avoid sealing parts during high humidity conditions.
4. Use Supplemental Moisture Control
In severe environments, combine VCI film with desiccants or moisture-absorbing solutions for added protection.
5. Seal Packaging Properly
Ensure VCI bags or film are sealed tightly to create an effective protective enclosure.
Learn How to Use ZERUST® VCI Products Correctly
Proper preparation and sealing are critical to preventing moisture inside VCI packaging. Review step-by-step guidance to ensure maximum corrosion protection performance.
Can ZERUST® VCI Protect Parts in Humid or Export Conditions?
Yes. ZERUST® VCI products are widely used for export shipments, overseas transport, and high-humidity storage.
However, success depends on proper preparation. ZERUST® Integrated Corrosion Technology works best when:
- Parts are clean
- Corrosive residues are removed
- Moisture inside VCI packaging is minimized
For demanding applications, ZERUST® also offers oil-based and water-based rust preventative solutions that may be used before packaging to enhance corrosion protection.
Explore ZERUST® Rust Inhibitors and Preventatives
For demanding export, humid, or long-term storage conditions, ZERUST® offers oil-based and water-based rust inhibitors and protective coatings designed to enhance corrosion protection performance.
Common Mistakes That Increase Moisture Risk
Avoid these frequent errors:
- Packaging hot parts that later cool and condense
- Sealing visible water inside VCI bags
- Assuming VCI absorbs standing moisture
- Ignoring humidity swings during international shipment
Proper preparation is just as important as selecting the right corrosion inhibitor.
Need Help Preventing Moisture Inside VCI Packaging?
If you are experiencing condensation, humidity swings, or corrosion during storage or shipment,
contact ZERUST® for expert guidance. Our corrosion specialists can recommend the right VCI
packaging and rust prevention solutions for your application.
ICT®510-PCR30 Post-Consumer Recycled (PCR) VCI Film is a 30% recycled polyethylene film containing proven ZERUST® Vapor Corrosion Inhibitors (VCI), providing cost-effective and versatile protection against corrosion damage for metals in shipping and storage.
ICT®510-C VCI Film provides cost-effective and versatile protection against rust and corrosion damage for metal assets in shipping and storage. Additionally, it’s available in ferrous, non-ferrous, and multimetal formulations, as well as various-sized rolls, sheets, tubing, and bags.
ICT®510-C VCI Sheeting provides cost-effective and versatile protection against rust and corrosion damage for metal assets in shipping and storage. Additionally, it’s available in ferrous, non-ferrous, and multimetal formulations, as well as various-sized sheeting.
ICT® VCI Poly Bags provide convenient and proven protection against corrosion damage for metals in shipping and storage. In addition, they are available in ferrous, non-ferrous, anti-tarnish, and multimetal protection types and various zipper, flat, and gusseted sizes.
ICT®510-C VCI Tubing provides versatile protection against corrosion, as the tubing offers a tailored packaging solution for parts of various sizes or long metal assets metals in shipping, storage, and work-in-progress.
ICT®510C-AN VCI Film series are nitrite-free and non-amine formulated products ideal for protecting highly porous and powdered metals in corrosive environments or for metal types susceptible to flash corrosion.
The Natur-VCI® series is an internationally certified, fully biodegradable, and compostable packaging material designed to protect against corrosion damage for metals in shipping, storage, and work-in-progress.
ICT®520-CB1 Anti-Tarnish Film protects silver, copper, bronze, brass, and tin from unsightly and damaging oxidation and tarnish, by blocking corrosion-causing acid gases before they reach and damage sensitive metal surfaces in shipping, storage, and work-in-progress.
ICT®510-CLHD is a high density VCI Film that’s lightweight yet strong packaging solution. Furthermore, it’s specifically designed for interleaving, laminating, and serving as a superior alternative to VCI kraft paper during shipment, storage, or work-in-progress.
ICT®520-FD VCI Film is a flame-retardant and high-strength packaging solution, meeting the DIN 4102-1 B2 standard, while providing cost-effective and versatile corrosion protection for steel and galvanized steel during work-in-progress, shipping, and storage.
ICT®520-HS High-Strength VCI film is a lightweight and durable packaging solution that’s less likely to puncture or tear compared with traditional polyethylene film. Making it especially suited for applications that have demanding corrosion protection requirements during work-in-progress, shipping, and storage.
ICT®504-LM Moisture Limiting VCI Film reduces moisture from seeping through the package by lowering the water vapor transmission rate by 30%. As a result, it effectively protects against corrosion damage for metals in international shipments and long-term storage.
ICT®510-OPS VCI Shrink Film is an 8-mil, high-strength shrink film integrated with ZERUST® Vapor Corrosion Inhibitor (VCI) technology and UV stabilizers, designed specifically for the long-term outdoor preservation of large assets.
ICT®510-SRK Film is polyethylene shrink film impregnated with Vapor Corrosion Inhibitors that shrinks tightly around the item when subjected to heat, providing a contoured fit and VCI protection.
ICT®510-ATS Anti-Static VCI Film provides cost-effective and versatile protection for electronics and electrical components against electrostatic discharge and corrosion damage in shipping, storage, and work-in-progress.
ICT®540-SDA Advanced VCI Film is a premium corrosion-inhibiting packaging product combining ZERUST® Vapor Corrosion Inhibitor (VCI) chemistry with unique oxygen and gas-blocking properties for use in extreme long-term storage and challenging conditions.
