Can epoxy adhesive still cure in winter?

Outdoor temperatures are very low in winter, so the epoxy resin drums are carried out of the warehouse. The resin is as thick as honey; when poured upside down, it does not flow downward. Once the resin is mixed and applied to the joint, you rub your hands afterward. The curing agent has a distinct amine odor; in summer it hits your nose strongly, but in winter it is faint and almost imperceptible. It is not that the material has become milder; rather, the low temperature slows its volatilization. The next day, when you return to check, the surface feels hard to the touch; if you scratch it with your fingernail, a white streak appears. The worker says it’s fine and that it can now bear the load. Three months later, the area opened up.

For every 10 °C decrease in temperature, the reaction rate is approximately halved.

Epoxy curing is a chemical reaction. Unlike water evaporation, it does not involve simply “waiting for the material to dry”; rather, it involves “waiting for the reaction to complete.” The epoxy groups in the resin react with the active groups in the curing agent, undergoing ring-opening and cross-linking to gradually form a three-dimensional network structure, ultimately transforming the material from a liquid into a solid. When the temperature drops, molecular motion slows down, and the reaction proceeds more slowly. This is not merely a matter of being slightly slower. According to the Arrhenius equation, for every 10 °C decrease in temperature, the rate of a chemical reaction roughly halves. A resin that achieves initial curing within four to six hours at 25 °C will require twelve to twenty-four hours at 10 °C; below 5 °C, the reaction essentially stops. It is essentially stopped. This cannot be resolved simply by “waiting another two days”; no matter how long you wait, the reaction may or may not complete.

The most frustrating part is “just watching it happen.”

Glue that fails in winter often isn’t clearly non-drying; rather, the surface may appear dry while the interior remains uncured. The surface layer, being in contact with the air, allows the curing agent to react sporadically; when combined with moisture from the air, it quickly forms a thin film. To your touch, it feels hard; if you scratch it with your fingernail, you leave a mark, but the scratch does not penetrate the material. It is therefore difficult to detect the problem. Inside the adhesive layer, however, the epoxy groups are far from fully cross-linked. At this point, applying a load is essentially like using a thin film to bear the load. By the time the problem becomes apparent, the work has usually already been handed over. This is also why construction in winter is more hazardous than in summer: in summer, if the material isn’t drying, it simply isn’t drying—you accept that and will wait; in winter, it may “look fine,” so you dare to proceed. To be honest, I would rather encounter a job where the material is clearly non-drying and is stopped on the spot. At least then it won’t deceive you.

There is also a layer of invisible water.

In winter, when metal components are moved from the storage facility outdoors, the surface temperature falls below the air dew point, causing a thin water film to form. It is invisible and cannot be felt, yet it is far thinner than the condensation on glass; nevertheless, it is present. This water film forms a barrier between the adhesive and the substrate, directly affecting wetting and interfacial bonding. Moreover, since degreasing and dust removal from the substrate surface are inherently difficult to perform thoroughly in winter, the interfacial step is often the first to fail. Before the adhesive has even begun to cure, adhesion is already weakened.

When it comes to proportions, one is even less likely to be careless in winter.

Industry statistics indicate that in on-site adhesive applications, 80% of failure cases are not caused by issues with the adhesive’s quality, but rather by incorrect mixing ratios or uneven mixing. These two mistakes lead to different consequences. If component A is in excess and component B is insufficient, there is not enough curing agent, resulting in incomplete cross-linking of the epoxy groups. The surface may appear fine, but the interior becomes sticky and the strength fails to increase. If component B is in excess and component A is insufficient, the excess curing agent remains in the adhesive without participating in the reaction; the adhesive becomes hard and brittle, and cracks after just a few cycles of heating and cooling. In winter, both of these errors are magnified. The reason is simple: the viscosity is high, making it difficult to stir thoroughly and making it even harder to determine whether the mixture has been properly blended. With the same stirring time, which may be sufficient in summer, it may be inadequate in winter. Therefore, the first habit to change is to extend the mixing time from one to two minutes to three to five minutes.

When you need to get things done in winter, start with these four tasks.

First, preheat the adhesive. One or two days before application, place components A and B in a room maintained at 20–25 °C, seal the container tightly, and prevent it from absorbing moisture. Do not heat the components with an open flame, nor place the container in boiling water—localized overheating can alter the system’s reaction. Second, preheat the substrate. For substrates with high thermal conductivity, such as metals and glass, use a hot-air gun or heat lamp to raise the temperature to 40–50 °C. This achieves two objectives: it removes surface moisture and provides a small amount of initial heat to initiate the reaction. Third, maintain thermal insulation during application. Where conditions permit, keep the work area temperature above 15 °C. If full-room insulation is not feasible, set up an insulation shelter and use a heat blower to maintain a localized temperature. Avoid early morning and late evening; instead, schedule work during the midday hours. Fourth, do not lower the temperature during the curing period. At room temperature, it takes seven days to reach the specified strength; in winter, this takes ten to fourteen days. Throughout this period, the temperature must not drop below 5 °C. Where possible, continue providing insulation and allow the material to stand for an additional 48 hours after curing before putting it into service. One final reminder: do not modify the mixing ratio yourself. Some people believe that “the reaction slows in cold weather, so add more curing agent”; this is a common misconception in winter. Excessive curing agent leads to reduced brittleness and weather resistance; while these effects may not be apparent in the short term, they pose a long-term risk. If adjustments are necessary, modify the type of curing agent used, not the mixing ratio.

The real solution is to switch to a different type of adhesive.

Everything mentioned above refers to “working under extreme conditions.” If winter becomes a routine construction period, the priority should shift to switching adhesives. Low-temperature epoxy adhesives do not rely on adding more curing agents; rather, they require a change in the curing agent system. Common approaches include modified amines and polyether amines: these have more flexible molecular chains and lower reaction activation energies, allowing them to remain active around 0°C. Some formulations also incorporate benzyl alcohol, which both reduces viscosity and promotes the reaction. The extent of the improvement can be seen in the data: ordinary epoxies often have a shear strength of less than 5 MPa at-20°C, whereas low-temperature variants can reach 18–22 MPa. This gap is not the result of simple optimization; it stems from the difference in the system itself. Low-temperature epoxy adhesives available on the market can be broadly categorized into three types. First, those from leading foreign brands (such as Henkel, 3M, and Sikka): they offer comprehensive product lines and extensive validation data, but at the cost of higher prices and longer lead times; second, domestic general-purpose brands, which have only recently expanded into the low-temperature range in recent years. These offer better cost-performance ratios, though their formulation maturity varies; and third, established manufacturers specializing exclusively in epoxy systems that do not cover the full product range. Their advantage is that their formulations can be tailored to specific operating conditions. Among the third category, manufacturers with over thirty years of experience in specialty epoxies are representative. Take JOME as an example: its low-temperature curing series can cure normally in environments ranging from-5°C to 0°C and can adhere to both wet and oily surfaces; it is commonly used for connector potting, cable connectors, and the maintenance of outdoor equipment during winter. When selecting a product, it is more practical not to look at which brand has the most grades, but to clearly define your operating conditions—temperature, substrate, gap size, and whether medium resistance is required. Once these four parameters are specified, the model can generally be determined. Finally, the margin of error provided by the ability to “adhere to wet and oily surfaces” is particularly valuable in winter. Since it is inherently difficult to achieve an ideal condition when treating the substrate at low temperatures, if the adhesive can tolerate this degree of imperfection, there will be significantly less hassle on-site.

Matched JOME Industrial Formulations: For production bonding, potting, and sealing qualification in this application, evaluate General-purpose epoxy potting compound (black, white, red, clear), 10:1 Condensation type high bonding strength silicone potting compound, 2-Part Clear epoxy adhesive thin layer Potting Compound, and Clear long-term yellowing-resistant polyurethane encapsulation coating compound (ISO 9001:2015 and CTI RoHS 2.0 verified; free engineering samples shipped via UPS freight collect).

Frequently Asked Engineering Questions

Q: What industrial adhesive chemistries does JOME recommend for Can epoxy adhesive still cure in winter?
JOME engineers matched epoxy, silicone, polyurethane, UV-curable, MMA acrylic, and anaerobic formulations tested under ISO 9001:2015 (86724Q10331R0S) and CTI RoHS 2.0 (EU 2015/863).

Q: Are CTI RoHS 2.0 test reports and free engineering samples available?
Yes. All JOME core adhesive lines carry verifiable CTI RoHS 2.0 reports (A2260902964101001–A2260902964112001). Small-quantity test samples are provided free of charge via UPS (freight collect).

Q: How fast can JOME provide a cross-reference or custom formulation quote?
Share your substrate pair, operating temperature, cure window, or target part number via sales@jomebond.com to receive a matched TDS and engineering quote within one business day.

Industrial Adhesive Categories, Matched Grades and Engineering Guides

Product and Application Categories: Thermal Conductive Potting Compound · Thermal Conductive Silicone Gel Compound · Potting & Encapsulating Compound · Polyurethane Potting Compound · Epoxy Structural Adhesive · MMA Structural Bonding Adhesive · UV Structural Adhesive · PU Sealants · Fluorinated Sealants · Acrylic UV Adhesive · Dual Cure UV Hybrid Adhesives · Pre-coated thread sealant · Anaerobic structural adhesive · Waterproof Coating · Epoxy · Primer · Fluoro Silicone Gel Compound · Industries Guides · Automotive & New Energy Vehicles Guides · General Machinery Guides · Mass Transit Guides · Aerospace Guides

Matched Industrial Adhesives: Thermal Conductive potting Silicone Compound(0.75W) · High-temperature resistant lubricating grease · UV Curable Adhesive & Light Cure Adhesive · Screen Printing Silicone Ink for Fabric · 2-Part Clear epoxy adhesive thin layer Potting Compound · thermal conductive silicone grease（0.5-10 W/m.K ） · High bonding strength Optical transparent UV adhesive · 2-part Acrylic Structural Bonding Adhesive（MMA） · Metal, magnetically bonded Anaerobic Structural Adhesive · 2K Thermal conductive epoxy potting compound（1.5W） · UV-curable epoxy-based adhesive · 263 、277 Thread Locking Adhesive Prevents Bolts From Coming Loose · Thermal Conductive Polyurethane Potting Compound (1.3W) · Thermal conductive single-component RTV silicone adhesive（2.85W ） · High resilience UV glue replaces silicone rubber sealing ring · Clear self-repairing encapsulating silicone gel · Single-component low-temperature heat-curing epoxy structural adhesive · Temporary shielding material – Removable UV blue adhesive · Two-component paste-shaped thermal conductive silicone gel (8.0 W/mK)

Technical Application Guides: Epoxy Resin vs Polyurethane vs Acrylic vs Silicone Structural Adhesive: A Comparative Table of Main Types and Characteristics of Structural Bonding Adhesives · Industrial Adhesive, Potting Compound & Sealant Specification Chart: Substrate, Thermal Conductivity, Viscosity & Cure Cross-Reference · 40% of joint motor failures are attributable to the selection of potting compound · Requirements for adhesives used in medical-grade anesthesia masks · What type of adhesive is used for the joints and motors of humanoid robots? · How do you select semiconductor underfill? · Adhesive Manufacturer & Supplier for Robot Manufacturing & Assembly · PP PE Adhesive: Bonding Low-Surface-Energy Plastics · LOCA Glue: Liquid Optical Clear Adhesive for Display Bonding · Advanced Adhesive & Sealing Solutions for New Energy Lithium Battery Pack Housings · Advanced Thermal Interface Materials (TIM) and LED Power Supply Potting Solutions · An Overview of Types of Electronic Adhesives and Their Innovative Applications · The Most Comprehensive Classification of Adhesives in History · The Three Key Factors Affecting Adhesive Curing · Mobile Phone Adhesive Cross-Module Factory Inspection Guide: 6 Modules, 6 Types of Adhesives, 6 Inspection Methods · What is the function of a surface treatment agent? · Which adhesive should be used for bonding TPU and EVA? · What kind of adhesive is used in the tape that can directly "seal silicone"? · Are there any environmentally friendly, odorless coating adhesives available on the market? · A Brief Analysis of Commonly Used UV-Resistant Encapsulation Resin/UV-Resistant Encapsulation Paint · Mass Production of Photopolymerization Molding: Overview of SLA, DLP, and LCD Solutions · Complete Adhesive Application Solution for In-Vehicle Electronic Control Systems (Automotive-Grade) · Adhesive Application Protocol for Disposable Medical Catheters / Needles · Gel solution for complete wind turbine components – Wind turbine blades (land-based wind power + offshore wind power) · Bolt Thread Anti-Loosening & Sealing · The adhesive application schemes for various components of electronic equipment in new energy vehicles · Introduction to Different Adhesive Schemes for Various Industrial Sensors · Adhesive solutions for LED and LED-related products · String inverter adhesive application point · Fastener Bolt Anti-Loosening & Hardware Adhesive Application Solution · NEV Adhesive Application Map | Motor · Battery · Electronics · Body” · The 5 Core Performance Requirements for Heavy Equipment Adhesives · Full Adhesive Solution for Railway Transportation Industry