Long-term indoor storage of large spare parts such as shafts, bearings, rotors, gears, and housings requires a deliberate and systematic corrosion control plan. Even in indoor environments, humidity, condensation, and airborne contaminants can cause rust and surface degradation over time. ZERUST® recommends a comprehensive approach that combines surface preparation, rust preventative coatings, VCI packaging, and environmental management to effectively protect large spare parts stored indoors.
The first step is proper surface preparation, which is critical for effective corrosion prevention. All parts should be thoroughly cleaned to remove machining residues, oils, and fingerprints that can accelerate corrosion. ZERUST® AxxaWash™ industrial cleaners and degreasers are designed for this purpose, safely removing hydrocarbon soils and contaminants without leaving corrosive residues. Once cleaned, the metal surface must be completely dried to eliminate residual moisture, and any handling should be done with clean, dry gloves to avoid recontamination.
After preparation, apply a ZERUST® Axxanol™ rust preventative coating selected for the expected storage duration and environmental conditions. For short-term indoor protection (up to 1 year) in controlled conditions, a light oil film such as Axxanol™ 33 provides reliable coverage and easy removability. For medium-term storage (1–2 years), particularly in areas with moderate humidity, Axxanol™ 750-NV or 758-NV delivers excellent contact corrosion protection with a water-displacing oil film that resists humidity and oxidation. For longer-term storage (2–3 years) or areas subject to fluctuating humidity, Axxanol™ A35-8030 offers a durable oil-based barrier that provides extended corrosion protection. When storage extends beyond three years, combining a coating such as Axxanol™ A35-8030 with ZERUST® ICT® VCI film or bags ensures long-lasting, sealed protection against moisture and condensation.
Specific component types benefit from tailored protection methods. Bearings should be coated with Axxanol™ 33, wrapped in ZERUST® ICT® VCI paper, and sealed within ZERUST® ICT® VCI poly bags to trap the vapor corrosion inhibitors. Shafts and machined surfaces can be protected with the same oil-based coating and then wrapped with ICT® VCI paper and film, ensuring that all seams are sealed airtight with packaging tape.
To further protect large spare parts stored indoors, ZERUST® recommends integrating vapor corrosion inhibitor (VCI) technologies. ZERUST® ICT® films and papers emit protective vapors that form an invisible molecular barrier on metal surfaces, while ZERUST® Vapor Capsules, ActivPak®, or Z-PAK® VCI emitters provide localized vapor protection for enclosed areas such as crates, totes, or housings.
Environmental control is equally important. Even in indoor storage, maintaining relative humidity below 50%, avoiding temperature fluctuations, and ensuring adequate air circulation help prevent condensation. To actively control moisture inside sealed packaging, totes, or enclosures, ZERUST® ActivDri™ PWA Packets provide combined moisture absorption and vapor corrosion inhibition, helping stabilize the microenvironment and further reduce the risk of humidity-driven corrosion during long-term indoor storage.
Finally, all stored components should be periodically inspected, ideally every 6–12 months, to check for any signs of condensation, corrosion, or coating deterioration. Packaging integrity and seals should also be verified, and coatings reapplied as necessary to maintain protection. By following this structured approach and using AxxaWash™ cleaners, Axxanol™ rust preventatives, ICT® VCI packaging, and regular environmental monitoring, ZERUST® helps manufacturers and maintenance teams ensure that critical spare parts remain clean, dry, and corrosion-free throughout their storage period. This process-driven methodology is central to the ZERUST® Z-CIS® (Corrosion Inhibiting System) approach, which provides consistent, long-term protection and peace of mind for industrial assets. For guidance on selecting the best solution for your needs, you can contact ZERUST®/EXCOR® to speak with a technical service representative.
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™ 750-NV is a rust preventative oil that forms a clear, thin, oily film on the metal surface, providing a moisture barrier and powerful corrosion protection against aggressive environments such as salt air and humidity.
Axxanol™ 758-NV is a non-staining rust preventive oil that forms a clear, thin, oily film on the metal surface, providing a moisture barrier and powerful corrosion protection against aggressive environments such as salt air and humidity.
Axxanol™ A35-8030 is a long-term rust preventative oil that forms a light, thin, oily film. As a result, it provides powerful corrosion protection against aggressive environments, such as salt air and humidity. In addition to corrosion protection, it provides lubricating properties that help reduce friction and support smooth assembly and disassembly of metal parts.
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® 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®420 is an acid-free, pH-neutral, and non-abrasive VCI kraft paper that merges the practicality and cost-efficiency of paper-based packaging with advanced corrosion protection. Consequently, it streamlines the preservation of metals during work-in-progress, shipping, and storage.
Vapor Capsules are portable VCI emitter diffusers containing proven ZERUST® Vapor Corrosion Inhibitors (VCI). They protect metals in hard-to-reach areas of control panels, electrical cabinets, or other enclosed spaces from corrosion, even when they are in operation. Additionally, use these VCI emitter diffusers as a supplement to other ZERUST® VCI packaging products for added protection.
ActivPak® is a versatile and powerful fast-acting VCI sachet designed to address flash rust and corrosion concerns in demanding scenarios, including overseas shipping and polluted factory environments.
Z-PAK® is an economical, effective, and easy-to-use vapor corrosion inhibitor (VCI) diffuser packet that can be used alone or, more typically, with other ZERUST® packaging products to provide robust temporary corrosion protection for ferrous metals during shipment, storage, or work-in-progress.
