Wood and pallets causing corrosion: How ZERUST VCI packaging eliminates the risk
When it comes to the transport and storage of valuable metal components, wooden packaging and pallets are often the natural choice. However, even though wood is solid and economical, research shows that wood-induced corrosion and pallet-induced corrosion are real and costly risks. Under the right conditions, wooden pallets and crates accelerate the corrosion of metals, leading to rust, staining, and even structural failure!
ZERUST®/EXCOR® offers a simple solution: remove the parts from direct contact with wood and protect them with VCI (Vapor Corrosion Inhibitor) poly packaging. Here is what science says, and why ZERUST® packaging is the best choice.
Why wood and pallets cause corrosion
1. Moisture content is critical
Wood absorbs moisture from the surroundings. When the moisture content exceeds 15–18%, it enables electrochemical corrosion of metals. Below this threshold, corrosion is negligible, but above it, the rate increases dramatically². This is one of the most important reasons why wood causes corrosion in metal parts that are stored or transported on pallets.
2. Copper-based wood preservatives make pallets more corrosive
Modern pallets are often treated with preservatives such as alkaline copper quaternary (ACQ) or copper azole (CA). These preservatives contain copper ions, which migrate through moist wood and accelerate the oxidation of steel and galvanized fasteners³. In practice, this means that pallet-induced corrosion is not just a theory, but a documented result.
3. The chemical composition of wood worsens the problem
Even untreated wood can emit organic acids like acetic acid and formic acid. These lower the pH value around metals and increase the corrosion rate. Some types of wood contain tannins, which can either inhibit or accelerate corrosion depending on the conditions, but a lower pH value consistently increases steel corrosion⁴.
4. Scientific tests confirm the risk
Both long-term studies and accelerated laboratory tests confirm that galvanized steel corrodes faster than ordinary carbon steel when it comes into contact with treated wood, especially under high-moisture conditions. The evidence that wood and pallets cause corrosion is consistent across multiple studies¹.
The hidden costs of wooden packaging
The risk of pallet-induced corrosion can translate directly into:
Rusty or stained parts upon arrival.
Loss of mechanical strength in assemblies.
Customer satisfaction and warranty costs.
Wooden pallets are strong for transport, but unpredictable in a corrosive environment.
How ZERUST® VCI poly packaging solves the problem
ZERUST® VCI poly film and bags eliminate uncertainty by creating a controlled microclimate around your parts:
Stops wood-induced corrosion: By isolating metal parts from wooden pallets, VCI packaging prevents acids, tannins, and copper ions from coming into contact with the components.
Protects against moisture: ZERUST® films dampen moisture changes and reduce humidity fluctuations that lead to corrosion.
Proven VCI technology: Safe, invisible VCI molecules deposit on metal surfaces and interrupt the corrosion reaction.
Globally trusted: For over 50 years, ZERUST® has been the first choice for manufacturers in the automotive, aerospace, and heavy equipment industries.
Scientific studies confirm what many manufacturers know: Wood and pallets that cause corrosion are real threats during the storage and transport of metal.
The good news is that you do not need to stop using wooden pallets; you just need to protect your parts. With ZERUST® VCI poly packaging, you can retain the logistical advantages of wood while eliminating the corrosion risk.
Protect your shipments. Protect your reputation. Choose ZERUST VCI packaging from Reál Marine!
This post is taken from the blog of Zerust.
Sources:
- Zelinka, S.L. & Stone, D.S. Corrosion of metals in wood: Comparing the results of a rapid test method with long-term exposure tests across six wood treatments. Corrosion Science, 2011.
- Zelinka, S.L. Corrosion of Metals in Wood Products. In Developments in Corrosion Protection, InTech, 2014.
- Zelinka, S.L. Guide for Materials Selection and Design for Metals Used in Contact with Copper-Treated Wood. USDA Forest Products Laboratory, GTR–227, 2013.
- Zelinka, S.L. & Stone, D.S. The Effect of Tannins and pH on the Corrosion of Steel in Wood Extracts. Materials and Corrosion, 2011.
