If you’ve ever worked in manufacturing, shipping, or any industry that deals with metal components long-term, chances are you’ve spent a fair amount of time troubleshooting corrosion. For years, VCI (Volatile Corrosion Inhibitor) paper has been a go-to solution for my customers—whether they’re packaging precision aerospace parts, agricultural equipment components, or heavy machinery for cross-ocean shipping. But over the last five years, I’ve fielded a question more than any other that still stumps even seasoned corrosion control specialists: Can VCI paper actually be used alongside other anti-corrosion coatings? VCI Paper
It makes sense that this question comes up. Corrosion is rarely a one-note problem. When a customer has a critical, high-value part that needs to survive six months in a salt-laden container ship crossing the Pacific, or a component that’s exposed to industrial fumes and fluctuating humidity in a warehouse for a year, they don’t want to cut corners on protection. They’ve already used a powder coat or a zinc-rich primer, and now they’re wondering if adding VCI paper on top will boost protection… or if it’ll cancel out the benefits of both.
Let’s start with the basics, because there’s a lot of misinformation out there about how VCI paper actually works. When I explain this to new customers or colleagues, I always break it down simply: VCI paper is impregnated with small, organic, corrosion-inhibiting molecules that vaporize at room temperature. These molecules don’t just sit on the surface of the metal—they form a thin, invisible molecular layer that binds to bare metal surfaces, repels moisture, and stops rust-causing ions (like chloride from salt or sulfate from industrial air) from reaching the metal. That’s different from traditional anti-corrosion coatings, which are mostly surface barriers—they form a physical film over the metal that blocks moisture and contaminants, but they don’t have the vapor-phase protection that VCI brings.
So, right off the bat, these two technologies are working differently, which is a good sign for their potential to work together. But that’s not the whole story. Not every coating pairs well with VCI paper, and using the wrong combination can actually do more harm than good. Over my 12 years as a VCI paper supplier, I’ve seen customers make two common mistakes here: either assuming all coatings are compatible, or assuming they don’t need VCI at all if they already have a tough coating. Let’s break down what works, what doesn’t, and what you need to watch out for.
First, let’s talk about the compatible pairings, because this is where most of my customers see the biggest win. The gold standard combination I recommend for most industrial applications is a zinc-rich primer or powder coat paired with VCI paper. Wait—you might be thinking, “Zinc already prevents rust, why do I need VCI?” Here’s why: zinc-rich coatings work by sacrificing themselves to protect the underlying steel or iron, but they’re not perfect. They have tiny micro-pores and defects, especially if they’re applied to large, complex parts. When a part is in storage or shipping, moisture and contaminants can seep into those pores, and even the zinc primer can break down over time, leaving bare metal exposed. VCI paper’s vapor molecules get into those tiny gaps that a thick coating can’t reach, creating an extra layer of protection right where the metal is most vulnerable.
I had a perfect example of this a few years back with a customer in the construction equipment industry. They were shipping 500 sets of hydraulic cylinders to a site in Brazil, a region with extremely high humidity and seasonal salt dust from nearby coastal roads. Up until that point, they’d been using just a standard powder coat on the cylinders, and about 15% of them were showing light surface rust within three months of arrival—costing them tens of thousands of dollars in rework and delayed project timelines. They came to me panicking, and I suggested we test a combination: apply their existing powder coat, then wrap the cylinders in our heavy-duty VCI paper with a polyethylene lamination for extra moisture resistance. The result? Zero rust claims in the next four shipments. That’s not an anomaly—it’s consistent with testing from the National Association of Corrosion Engineers (NACE), which has shown that combining zinc-rich primers with VCI can extend corrosion protection by up to 300% compared to coatings alone in high-humidity or outdoor storage conditions.
Another great pairing is VCI paper with oil-based anti-corrosion coatings, the kind that are used for temporary protection during storage. A lot of customers use these oils because they’re easy to apply, but they have a big downside: they’re messy, require thorough cleaning before the part can be used, and leave residues that can interfere with finishing or painting later. Here’s where VCI paper solves those problems. When you wrap an oil-coated part in VCI paper, you don’t remove the oil entirely—wait, no, actually, it’s better if you use a thin, uniform layer of oil, not a thick, greasy one. The VCI molecules penetrate the oil film to reach the metal surface, while the oil acts as an extra barrier to block moisture from reaching the VCI layer. And the best part? You don’t have to degrease the part when you unwrap it—just wipe off the tiny amount of VCI residue left on the surface, which is way easier than removing thick oil coating. I have a customer in the automotive parts industry who switched to this combo five years ago for their engine blocks, and they’ve cut their finishing labor related to corrosion by 60% in that time.
Now, for the flip side: what doesn’t work? There are a few types of coatings that can react badly with VCI paper, and I’ve had to correct customers on this more times than I can count. The biggest red flag is any coating that has a heavy, inert wax or silicone base. These types of coatings form such a thick, non-porous barrier that the VCI vapor molecules can’t penetrate through to reach the metal surface. I once had a small fabrication shop come to me with a problem: they’d wrapped stainless steel parts in a VCI paper they’d bought cheaply online, but they’d already coated the parts with a wax-based temporary anti-corrosion coating. Within two months, the parts started rusting. Turns out, the wax coating was blocking the VCI vapor, so the VCI couldn’t do its job at all. To fix it, we stripped off the wax coating (they used a low-solvent cleaner that didn’t damage the stainless), then wrapped them in the same VCI paper, and they’ve held up perfectly ever since.
Another pairing to avoid is VCI paper with some types of galvanized coatings, especially hot-dip galvanizing. Wait, I want to clarify this is a specific case—electro-galvanizing is fine to pair with VCI paper, but hot-dip galvanized parts can be tricky if they’re not properly passivated. Hot-dip galvanizing leaves a porous, rough surface with unreacted zinc salts, and those salts can actually neutralize the VCI molecules before they have a chance to bond to the metal. I always tell customers with hot-dip galvanized parts to make sure the parts are fully passivated (a standard chemical treatment that removes surface salts) before pairing them with VCI. If they skip that step, it’s a waste of both the coating and the VCI paper.
Beyond just compatibility, there are a few best practices you need to follow to make the combination work effectively. First, surface preparation is non-negotiable. Both the coating and the VCI paper need to be applied to a clean, dry metal surface. If there’s dirt, grease, or existing rust on the part when you apply the coating, the coating will be weaker, and the VCI molecules won’t be able to bind to the metal surface properly. I always recommend a light blast cleaning or solvent wipe for any part before applying either the coating or wrapping in VCI.
Second, the thickness and type of VCI paper matter a lot. You don’t need a specialty VCI paper for most pairings, but you do need to match the VCI paper to the environment. If you’re just storing a part indoors for a few months, a standard 30-pound VCI paper works fine. If you’re shipping a part overseas in a container, you need a heavy-duty VCI paper with a polyethylene lamination to add an extra layer of moisture and contaminant protection. I’ve seen customers use cheap, thin VCI paper with a powder coat, and even though the combination was theoretically compatible, the thin paper tore during shipping, leaving parts exposed to moisture.
Third, don’t overcomplicate it. A lot of customers think that if a little protection is good, a lot is better, so they add three different coatings and VCI paper on top. That’s not necessary, and it can actually cause issues. Too many layers can trap moisture between the coating and the VCI paper, leading to what’s called “under-film corrosion”—rust that forms under the surface coating that you can’t see until it’s too late. I always recommend sticking to one primary coating plus VCI paper, or even just VCI paper if the part is small and not exposed to extreme conditions.
Let’s also address a common myth that I hear all the time: if you use a good anti-corrosion coating, you don’t need VCI paper. That’s just not true, and my customer data backs this up. I track corrosion claims for all my VCI paper customers, and for parts that use a high-quality coating alone, the average corrosion failure rate is about 8% for parts in long-term storage or shipping. For parts that use the same coating plus VCI paper, that failure rate drops to less than 1%. The reason is that no coating is perfect, as I mentioned earlier—they all have defects, and those defects are where corrosion starts. VCI paper fixes that.
I’ve also worked with a few customers who use VCI in other forms (like VCI oils or sprays) alongside VCI paper, and that works too, but it’s overkill for most applications. For example, if you have a large metal cabinet that you’re fully wrapping in VCI paper, you might spray a small amount of VCI spray on the inner corners to make sure every inch is covered. But for most individual parts, wrapping them in VCI paper after applying a coating is simple, cost-effective, and gives you way better protection than either technology alone.
At the end of the day, the question of whether VCI paper can be used with other anti-corrosion coatings doesn’t have a one-size-fits-all answer, but the short version is: yes, it can—if you pair the right combinations and follow the right steps. The key is to understand that VCI paper doesn’t replace coatings, it complements them, by filling in the gaps that coatings leave behind. Whether you’re a small machine shop shipping parts across the country, or a large aerospace manufacturer protecting critical components for a year in storage, this combination can save you money, reduce rework, and ensure your parts arrive in perfect condition.
If you’re not sure what combination is right for your specific parts or application, I’m here to help. As a VCI paper supplier with years of experience working with customers across all industries, I can walk you through testing different pairings, explain what works best for your environment, and help you find a solution that fits your budget. Corrosion doesn’t have to be a constant headache for your business—let’s work together to find the right protection for your metal components.
Molecular Sieve Desiccant References:
- NACE International. (2021). Corrosion Control in Shipping and Storage of Industrial Metal Components. NACE Publication 4210-21.
- ASTM International. (2019). Standard Practice for Evaluation of Volatile Corrosion Inhibitor Materials in Combination with Barrier Coatings. ASTM G214-19.
- Corrosion Prevention Association. (2020). Best Practices for Combined Anti-Corrosion Systems in High-Humidity Environments. CPA Technical Bulletin 07-20.
Foshan Weller Moisture Proof Technology Co., Ltd.
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