Is it too cold/too humid to glue? The impact of temperature and humidity on sealants is beyond imagination!

The ambient temperature and humidity not only affect your comfort during construction, but also profoundly affect the sealant’s extrusion, flowability, surface drying time, curing speed, and final bonding performance and durability. Ignoring environmental conditions often leads to construction difficulties, poor results, or even failure.

Core skills: understand limitations, create conditions, and pre-adapt materials

The impact of temperature (key!):

Low temperature (usually <5°C):

Problems: The colloid becomes thicker and harder, making it difficult to extrude; poor flowability, difficult to fill joints and trim; the curing reaction almost stops or is extremely slow, and the surface drying and complete curing time are greatly extended; bonding strength is difficult to form.

Countermeasures:

Avoid construction: Try to apply above 5°C. Check the product manual for the minimum application temperature (some high-performance glues can be as low as -10°C).

Preheating materials: Place the sealant tube in a warm room (such as 20-25°C) for at least 24 hours in advance. Never use open flames or high temperatures to bake!

Preheat the substrate: If possible, use a heat gun (pay attention to the safe distance to avoid local overheating) to slightly heat the gap area to be applied (make sure it is dry).

High temperature (usually refers to >35°C):

Problems: The colloid becomes thinner, the fluidity is too strong, and it is easy to sag or collapse; the surface drying time is greatly shortened, and the time window for trimming and shaping and masking tape removal is extremely short; the curing speed is accelerated, but it may lead to incomplete deep curing (“burnt on the outside and tender on the inside”); solvent-based glue may bubble more seriously.

Countermeasures:

Choose fast-drying glue: If the product has a fast-drying model available.

Sectional construction: Only apply a small section of glue each time, and trim and remove the masking tape immediately.

Cooling/shading: Avoid direct sunlight on the construction area, and try to apply in the morning and evening when the temperature is lower. Keep the material cool.

Speed ​​up the operation: Gluing, trimming, and tearing off the masking tape should be very fast and continuous.

Effect of humidity:

Principle: Most silicone adhesives and some modified silane adhesives (MS adhesives) require moisture in the air to trigger the curing reaction (moisture curing).

Low humidity (such as <30% RH):

Problem: The curing speed is extremely slow, and the surface drying and complete curing time are greatly extended.

Countermeasures: Wait patiently; if necessary, spray a small amount of water mist into the air during curing (be careful not to spray directly on the uncured adhesive!) or use a humidifier.

High humidity (such as >85% RH) or surface water:

Problem: Although it can accelerate surface drying, condensation or clear water on the surface or in the gaps of the substrate is absolutely taboo! It will seriously hinder bonding, leading to failure or even mold. Extreme high humidity may cause frost on the surface of some adhesives (reacting with CO2 in the air).

Countermeasures: Make sure the substrate is absolutely dry! Avoid construction on rainy and foggy days. If there is continuous rain after construction, pay attention to protect the incompletely cured adhesive.

💡 Key point: Be sure to read the temperature and humidity requirements on the product manual carefully before construction! They are the guarantee for the normal operation of the product. If you force construction beyond the range, you will be at your own risk. Try to operate under mild conditions of 10°C – 35°C, 40% – 80% RH.