How to use silicone sealant in summer?

Silicone sealant must be cured in order to play its structural bonding or sealing function, and its curing speed is related to the ambient temperature and air humidity, usually with the increase of temperature and humidity, the surface drying time of the sealant is shortened (single-component products), the deep curing speed is accelerated, which may have an adverse effect on the construction and function of the sealant, so in the summer construction, Take extra care.

1.The common problems

(1)The sealant appears foaming after construction

The methanol contained in the alcohol adhesive during the curing process will release gas (methanol begins to volatilize at about 50 ° C), especially in the case of direct sun and high temperature reaction is more intense. Concrete, all kinds of metal window frames are difficult to breathe, coupled with the high temperature and humidity in summer, the solidification will be faster, the gas released by the glue can only run out of the rubber layer that is never completely cured, and the bubbles of different sizes will appear on the cured rubber strip. The foaming phenomenon of sealant will lead to a decrease in adhesion, and the sealing effect will become worse. In the high temperature season, such as the selection of alcohol adhesive construction should be avoided in the direct sun, or take appropriate shading measures.

In addition, the summer thunderstorm weather is frequent, the substrate and glue seam are wet after the rain, such as the glue operation before the thorough drying, the moisture in the glue seam and the substrate can not be distributed to the air in time, and the foaming phenomenon will also occur. In this case, it is necessary to wait until the substrate or glue seam is completely dry before gluing.

(2)The sealant expands after construction

After the construction in the summer, due to the low humidity of the environment, the curing speed of the sealant slows down, and when the sealant surface has not cured enough depth, if the width of the glue seam changes (which is usually caused by the thermal expansion and cold contraction of the panel) is large, the surface of the glue seam will be affected, and the uneven phenomenon will occur. Its interior is solid, called "drum".

Although the drumming phenomenon will not affect the performance of the weatherproof sealant, it will affect the aesthetics of the curtain wall. Therefore, in the construction, you can improve the drum phenomenon after the construction of single-component sealant by changing the construction time of sealant, choosing products with faster deep curing speed or taking appropriate shading measures.

Should pay attention to the selection of a high level of sealant, choose a sealant with a relatively fast curing speed, glue under the appropriate environmental humidity, choose the appropriate construction time, in the summer high temperature weather, should pay attention to the storage conditions of the sealant, pay attention to avoid direct sunlight, keep the warehouse ventilated well, avoid humidity.