VCI metal compatibility chart: steel, copper, zinc and aluminum

This chart is for VCI papers, films and bags around bare metal in a closed package. It does not cover VCI oils or coatings, painted, plastic or rubber parts, or a product whose datasheet rates the metal differently; the datasheet of the product you buy governs. US defense packaging that cites MIL-I-8574E also follows its restrictions.

VCI compatibility chart by metal

The VCI compatibility chart below decides whether a metal can go in ferrous VCI packaging, needs a multimetal formula, or needs a test or a different method first. The Ferrous VCI column draws on ARMOR's R paper, an older formula the maker has since replaced with its Global paper (ARMOR G notice, accessed 2026), whose ratings favor steel, cast iron and tin (our reading of the chart). The Multimetal VCI column draws on ARMOR's MPI paper, which the maker describes as a multi-metal paper for aluminum, brass, copper and galvanized metal (ARMOR MPI page, accessed 2026). Zerust ratings and the chemistry come from the sources named in each cell.

The decisive rows are copper, zinc and aluminum: the ferrous paper is rated not compatible with all three, while the multimetal paper rates copper, brass, zinc and galvanized steel complete protection and aluminum good protection (ARMOR chart, accessed 2026). Read each cell as one maker's rating for one product, not a property of every VCI.

How do you read the VCI chart for a mixed-metal assembly?

You read the VCI chart for a mixed-metal assembly row by row and let the most restrictive metal decide the formula. Zerust recommends multimetal VCI for assemblies with steel and aluminum or with copper and steel interfaces, and checks whether alloys contain copper or manganese and whether different metals touch (Zerust, accessed 2026).

Worked example (illustrative assembly, real chart ratings): a steel pump housing with a brass fitting, a copper winding and soldered terminals ships in a VCI bag.

1. List every metal, including platings, solders and brazing alloys. Here: carbon steel, brass, copper and tin-lead solder.

2. Find the most restrictive row. Ferrous VCI is rated not compatible with copper and brass (ARMOR chart, accessed 2026), so the ferrous paper is out.

3. Check the multimetal column for each metal: steel good protection, copper and brass complete protection, solder testing recommended (ARMOR chart, accessed 2026).

4. Test the solder joints with the chosen product before release, because no rating clears them.

5. For US defense packaging, check MIL-I-8574E: brass with more than 30 percent zinc and solder with more than 9 percent lead cannot be packed with VCI at all (MIL-I-8574E, 1982).

6. Use one manufacturer's VCI products in the pack, because the GDV Transport Information Service states that products from different manufacturers are not compatible (GDV TIS, accessed 2026).

Why do copper, zinc and magnesium need special VCI formulas?

Copper, zinc and aluminum need special VCI formulas because VCI that releases amines alone makes the surface alkaline, which corrodes these metals while it protects steel; magnesium has no stated reason in these sources and needs a test. A 2020 EXCOR patent explains that the amine reaching the metal through the vapor phase sets an alkaline surface pH in condensed water, at which the oxide layer of ferrous materials is stable (US 10753000 B2, 2020). The same source states that amine-based VCI oils are not suitable for aluminum and copper base materials or galvanized steel, whose oxide layer degrades at these high surface pH values. With zinc and aluminum, it reports strong corrosion forming zincates or aluminates and, finally, the deposits known as white rust; copper materials often corrode by forming copper amine complexes (US 10753000 B2, 2020).

The same patent names two ways around this. When the amine and its carboxylic acid both reach the metal, as with amine carboxylates, the surface pH normally lies in the neutral range, which mostly helps non-ferrous metals; amine-free formulas can add benzotriazole or tolyltriazole to protect copper materials (US 10753000 B2, 2020). A peer-reviewed review adds that VCIs sometimes increase the corrosion rate of non-ferrous metals and alloys (Ansari et al., 2018).

For magnesium, MIL-I-8574E bars magnesium-base alloys (MIL-I-8574E, 1982), and ARMOR's chart has no magnesium row; its nearest row, aluminum magnesium alloy, is testing recommended on every product it lists (ARMOR chart, accessed 2026).

Where the VCI metal compatibility chart does not apply

The VCI metal compatibility chart does not apply outside a closed, clean, moderate-temperature package, and it does not replace the datasheet of the product you buy. MIL-I-8574E says VCI should not be applied to metal items whose surface temperature is greater than 150 °F (about 66 °C), and that package interiors should not remain above 85 to 90 percent relative humidity for prolonged periods (MIL-I-8574E, 1982). It also says items should not be cleaned with hydrochloric acid type metal cleaners or solvents containing sulfides, or exposed to fumes of hydrogen chloride, hydrogen sulfide or sulfur dioxide (MIL-I-8574E, 1982); follow the cleaner's SDS when cleaning parts before packing.

Three more limits apply. Under MIL-I-8574E, assemblies with plastic, painted or rubber parts need a passed compatibility test before VCI packaging, and assemblies with optical systems or precision moving parts already coated with a preservative are excluded (MIL-I-8574E, 1982). The standard laboratory test, NACE TM0208-2024, covers ferrous metal surfaces only (AMPP, 2024), so ask the supplier how non-ferrous ratings were tested. VCI rust preventive oils follow their own standard: JIS K 2246:2026 specifies rust preventive oils for metallic materials, primarily iron and steel (JSA, 2026).

When an assembly combines restricted metals, coatings and a long storage plan, a corrosion specialist should confirm the choice; Lubinpla can organize that case from your own documents, such as the TDS and SDS, and return one cited document for review.