What to pay attention to in the construction of weather-resistant glue

After the Spring Festival, major construction units ushered in the climax of resumption of work, and curtain wall projects have begun to arrange on-site sizing.

However, recently is the season of alternating winter and spring, the temperature difference between day and night changes greatly, and the project site is often accompanied by dew and humidity. The building curtain wall is prone to bulging and blistering when applying glue on site.

Let's distinguish together: "drum" and "bubble"

After the sealant has been applied for a period of time, the deformation and protrusions on the surface of the glue seam may be "bulging" or "blistering". The appearance and performance of the two are very similar, but the root causes of these two phenomena are different, and the corresponding solutions are also different.

The reason for the drum

(1) The sealant is squeezed during the curing process. Commonly used in aluminum panel curtain walls, because the thermal expansion coefficient of the aluminum panel itself is large, and the seam changes greatly when the temperature difference is large, resulting in the sealant being squeezed by the plate and bulging;

(2) The foam sticks do not match. If the size of the foam stick does not match the size of the interface, the foam stick will be pulled too tightly during the cushioning process, and then glue is applied immediately, and the later rebound of the foam stick will cause the sealant to bulge;

(3) The plate shakes before the sealant is cured. For example: windy weather or people walking, cause the sealant to bulge due to the displacement of the plate before it is fully cured.

cause of blistering

(1) The seams are wet or the accessories are damp before the glue injection;

(2) The surface temperature of the substrate is too high, and the reaction speed of the sealant is too fast;

(3) Air is wrapped in the glue during the sizing process, resulting in the formation of pores and blistering inside the sealant;

(4) The foam rod is damaged during installation.

The problems of bulging and blistering of silicone weather-resistant sealants are closely related to the construction environment and process on site. Especially in the construction period when the seasons alternate, the construction should be carried out according to the standard construction process to avoid problems.

(1) Select high-quality sealant products to ensure the quality of the project from the source;

(2) Choose a foam rod with a suitable diameter, and the diameter of the foam rod should be 120% of the joint width;

(3) Press the foam stick with a suitable tool to prevent the foam stick from puncturing and causing foaming;

(4) Make sure that the base material and foam stick are dried and sizing to prevent the vapour of the seam from volatilizing at high temperature and causing foaming;

(5) Avoid mixing air bubbles during the glue injection process;

(6) For the weather-resistant sealing of aluminum panel and aluminum-plastic panel curtain wall, please avoid the peak period of temperature accumulation and choose a suitable time for construction. Cloudy days are the best time to catch up with the construction period. If necessary, use twice gluing to solve the problem of bulging. .