Adhesives and Sealants: 6 Critical Storage Mistakes That Compromise Their Performance and Lifespan

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Adhesives and sealants are key components in many industrial applications, from the automotive industry to construction. However, their performance depends not only on proper application but also on storage conditions. Even minor deviations from recommended parameters—such as temperature, humidity, or light exposure—can cause irreversible changes in the material's structure. The result is weaker bonds, shortened lifespan, or even failure at critical moments. In this article, we focus on six of the most common mistakes that can occur when storing adhesive and sealing materials and show how to effectively prevent them.

1. Ignoring Temperature Conditions: Why Extremes Destroy Adhesives and Sealants

Adhesives and sealants are sensitive to temperature fluctuations, which can significantly affect their chemical stability and performance. When stored at excessively low temperatures (below 5 °C), many types thicken, crystallize, or even suffer irreversible damage to their polymer structure. For example, water-based dispersion adhesives may freeze and lose homogeneity after thawing, leading to uneven curing and reduced bond strength. Conversely, high temperatures (above 30 °C) accelerate polymerization or solvent evaporation, shortening the product's shelf life and potentially causing premature curing before application.

The ideal storage temperature ranges between 15–25 °C, with emphasis on maintaining a stable environment—rapid temperature changes are as harmful as the extremes themselves. For some special adhesives (e.g., anaerobic or cyanoacrylate types), manufacturers recommend even stricter conditions, often with a maximum temperature of 20 °C. Storage facilities should be equipped with regulated heating and cooling, ideally with real-time temperature monitoring. If transported or temporarily stored outside optimal conditions, the product must be allowed to acclimatize for at least 24 hours before use.

2. Inadequate Protection Against Moisture: How Water Alters Adhesive Properties

Moisture is a silent enemy of many types of adhesives and sealants, particularly those based on polyurethanes, silicones, or MS polymers. These materials react with water in the air, leading to premature polymerization, bubble formation, or loss of adhesive properties. For example, one-component polyurethane sealants begin to cure at relative humidity above 50 %, which shortens their open time and complicates application. In cyanoacrylate adhesives, moisture can cause instant surface curing, blocking the product's exit from the packaging.

Storage areas should have a relative humidity below 60%, ideally around 40–50%. Dehumidifiers, air conditioning, or hermetically sealed containers with desiccants (e.g., silica gel) serve this purpose. Packaging must be thoroughly resealed after each opening, and product residues should be protected from contact with air—by transferring them to smaller containers, for example, or using vacuum seals. For sensitive products (e.g., anaerobic adhesives), it is recommended to store them in their original packaging with a minimal amount of air above the surface.

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3. Improper storage of opened packaging: How to extend the shelf life of residues

Open containers of adhesives and sealants are particularly susceptible to degradation, even when temperature and humidity conditions are maintained. The main issue is contact with oxygen, which in many types (e.g., epoxy or acrylate adhesives) triggers oxidative reactions, leading to thickening, loss of tackiness, or the formation of a surface crust. In solvent-based adhesives, volatile components evaporate, altering viscosity and application properties.

To minimize these risks, it is crucial to transfer product residues into smaller, airtight containers as quickly as possible. Ideal options include metal or glass containers with sealing lids, or special containers with replaceable membranes for air-free dispensing. For viscous sealants, guns with a closing mechanism or applicators with a vacuum system can be used. It is also important to label containers with the opening date and maximum shelf life—most adhesives have a lifespan of 3–12 months after opening, even though unopened ones may last several years.

4. Neglecting Container Compatibility: When the Material of the Container Damages the Contents

The choice of appropriate container material is often an underestimated factor that can significantly affect the quality of adhesives and sealants. Some chemicals react with the container material, leading to product degradation or even hazardous reactions. For example, acidic or alkaline components can corrode metal containers, while solvents (e.g., acetone or toluene) damage plastics such as polyethylene or polypropylene. With epoxy adhesives, there is a risk of reaction with soft plastics, which can contaminate the product and reduce reactivity.

For most adhesives and sealants, the most suitable containers are those made of high-density polyethylene (HDPE) or glass, which are chemically inert and resistant to most solvents. Metal containers (e.g., aluminum or stainless steel) are used for special applications but require additional protection against corrosion. When transferring products, it is essential to ensure compatibility with the tool material—for example, metal spatulas may catalyze the polymerization of certain adhesives. Always follow the manufacturer's instructions regarding the type of container and any storage restrictions.

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Exceeding Shelf Life: How to Identify Expired Adhesive and Why Not to Use It

Every adhesive and sealant has a specified shelf life, which is indicated on the packaging or in the technical data sheet. This period is not arbitrary—it reflects the chemical stability of the product under optimal conditions. After its expiration, gradual degradation of polymers, separation of components, or loss of reactive properties occurs. For example, in cyanoacrylate adhesives (so-called instant adhesives), polymerization may already occur in the packaging, while in epoxy systems, adhesive strength decreases due to impaired curing ability.

Expired adhesive can be identified by changes in consistency (thickening, gel formation), component separation, unusual odor, or loss of tackiness. Even if the product may seem to "still work," its mechanical properties are often irreversibly damaged. For instance, in structural adhesives, joint strength may decrease by up to 50%, compromising the safety of the final product. Always check the expiration date and follow the FIFO (First In, First Out) principle—use older batches first. If in doubt, perform a test application on a material sample and verify adhesion using standard testing methods.

Incorrect Mixing of Multi-Component Systems: How Ratio and Technique Errors Reduce Performance

Multi-component adhesives and sealants (e.g., epoxies, polyurethanes, or silicones) require precise adherence to the component ratio and thorough mixing. Even a slight deviation from the recommended ratio can lead to incomplete curing, reduced strength, or impaired chemical resistance. For example, in epoxy adhesives, an excess of hardener causes joint brittleness, while its deficiency prolongs curing time and reduces thermal resistance.

Proper mixing technique is also crucial. Insufficient mixing leads to local concentration differences, which result in uneven curing or weak spots in the bond. Use a mechanical mixer with low speed (to avoid air entrainment) and mix for the duration specified in the technical data sheet – typically 2–5 minutes. For larger batches, check the homogeneity of the mixture visually or using a glass plate test. Remember that some systems have a limited pot life, after which the mixture begins to harden and can no longer be applied with quality.

Neglecting Safety Measures: How Storage Affects Fire Risk and Health

Many adhesives and sealants contain flammable solvents, reactive monomers, or corrosive components that require special attention during storage. Flammable products (e.g., solvent-based or methyl methacrylate-based) must be stored in a cool place, away from heat sources and open flames, ideally in a separate, well-ventilated area with fire protection measures. According to CLP and GHS regulations, these substances are labeled with warning symbols and require compliance with specific conditions, including a maximum storage temperature (usually up to 25 °C).

In addition to fire risk, some adhesives can release harmful vapors, especially if stored improperly or if the packaging is damaged. For example, isocyanates in polyurethane adhesives can cause respiratory sensitization, while some epoxy resins irritate the skin. Always store these products in their original, undamaged containers with tightly sealed lids and use personal protective equipment (gloves, respirators) when handling. Also, ensure the separate storage of incompatible substances – for instance, acids and alkalis can cause dangerous reactions or release toxic gases upon contact.

Want to be sure your adhesives and sealants last as long as possible?

Every chemical raw material requires specific storage and handling conditions. GCG Group provides detailed safety and technical data sheets with clear instructions for each product. Our experts will be happy to advise you on how to optimise storage conditions for your specific applications to ensure maximum performance and safety. Contact us – or browse our catalogue of over 1,300 products right away.