The following provides guidelines and suggestions for applying sealants below 40°F (4°C).
Sealant cure is slower at temperatures under 32°F (0°C) due to ice and frost on bonding surfaces. This can impact the cure, adhesion, and overall performance. To enhance sealant performance in cold weather, follow these guidelines.
- Allow the primer/sealant to reach room temperature by warming it for 24 hours before use to ensure smooth application.
- To prepare the surfaces, make sure to remove any dew, frost, or ice using an approved solvent like MEK (methyl ethyl ketone), toluene, or xylene. These solvents are particularly effective for cleaning in colder temperatures than IPA (isopropyl alcohol). However, for winter cleaning, consider using Isopropanol alcohol (IPA) and methylethylketone (MEK) since they are water-soluble and can efficiently eliminate condensation and frost. Make sure the substrates are clean and ready for sealing. This step is crucial to promote proper adhesion in cold weather conditions.
- Similar precautions should be taken with primers as with the sealants mentioned earlier when dealing with temperatures below 32°F. It’s important to note that these specific primers will have a longer drying time in colder conditions than warmer ones. Therefore, it’s crucial to exercise caution and allow sufficient time for the primer to dry completely before applying the sealant. This extra drying time is necessary to guarantee proper bonding and sealing in cold weather situations, enhancing the overall effectiveness of the sealing process.
Moisture Cure Sealants: In most cases, one-part sealants that cure through moisture reaction are influenced by temperature. Consequently, when temperatures drop, the curing process slows down due to reduced environmental moisture vapor levels. This extended cure time can become a concern, especially in colder conditions, where the installed temperature can be lower. It is essential to take appropriate precautions to safeguard against any potential issues related to the displacement of uncured sealant. Ideally, the sealants should be applied within a temperature range of 40°F (4°C) to 80°F. This range not only optimizes the curing process but also make sure the integrity and effectiveness of the sealant. It ultimately leads to a more reliable and durable seal.
Minimum Temperature: In the temperature range of 0°F (-18°C) to 40°F (4°C), it’s recommended to apply sealant at approximately 27°C. As mentioned earlier, high-conformance moisture-curing silicone and polyurethane sealants have been successfully applied even in icy conditions, reaching as low as -20°F (-29°C) when applying the proper techniques. However, it’s essential to consider that environmental factors, like humidity, sunlight, and wind, can influence the curing process, impacting the sealant’s performance. Thus, it’s essential to be mindful of these factors when working with these sealants in cold weather to ensure optimal results and long-lasting seals.
Apart from temperature considerations, the following points apply to these sealants.
- When dealing with moisture-curing substrates like mortar, EIFS, and concrete, providing additional time for these substrates to cure correctly, especially in colder climates is essential.
- Adequate time should be allowed for these substrates to cure before applying cleaners and primers in preparation for sealant application.
Dew Point: Condensation can form when the temperature reaches the dew point. The dew point is the temperature at which the air becomes saturated with moisture, leading to the formation of water droplets on surfaces. To address this, cleaning affected substrates below the dew point temperature is crucial before applying primers and sealants. Utilizing appropriate methods, like a two-rag wipe, helps remove any condensation, ensuring a suitable surface for primer and sealant application.
Wind Chill: Wind plays a significant role in surface preparation time. It directly impacts the application of primers and sealants. In more excellent conditions, the wind chill effect can lead to accelerated cooling of surfaces. This, in turn, affects the characteristics of the sealants, potentially reducing their flow rate and hindering their adhesion to substrates. Efficient tooling or wetting out of the sealant may become challenging under such circumstances. Therefore, allowing ample time for the joints to dry appropriately is advisable, as applying sealant in these conditions may leave undesired deposits.
Hydrocarbon Flame: Hydrocarbon flame is not recommended for drying joints. This method can adversely affect the sealant application process, potentially leading to compromised adhesion and overall performance. Exploring alternative and safer drying methods is advisable to provide a successful and reliable sealant application.
Addressing any factors that might hinder it is essential to provide proper adhesion. Moisture and contaminants on the surface can impede adhesion. Therefore, using a heater or dryer is crucial to eliminate excess moisture. However, be cautious, as rapid heating and cooling can occur on metal surfaces.
Before caulking, it’s essential to use a moisture meter to confirm that the substrates are dry. Additionally, keeping a control sample in the job office for reference can be helpful if there are any uncertainties. Isopropanol alcohol (IPA) and methylethylketone (MEK) are suitable for winter cleaning, as they are water-soluble and effective in removing condensation and frost.
It’s worth noting that each project should be evaluated individually. The environmental conditions can vary significantly from day to day, especially during the cold weather months when these variations are particularly pronounced.