How to use construction polyurethane sealant?

Polyurethane sealants are generally divided into two types: single-component and two-component:

1.Two-component sealant is composed of isocyanate-terminated prepolymer and additives as one component, polyol curing agent or polyol mixed with a small amount of diamine and other additives as another component.

2.One-component polyurethane sealant is a mixture of prepolymer and various fillers, and is sold in a cylindrical single package. The sealant cannot self-vulcanize in the container and must have good stability, which brings certain difficulties to the preparation of single-component sealant.

How to use polyurethane sealant:

1. Treat the construction surface: First dry the construction surface with a brush or cloth, and then wipe it with a damp cloth soaked in solution.

2. Strip filling material: When squeezing the sealant into the gap, it should only adhere to both sides of the joint. If the sealant bonds both sides and the bottom surface, the sealant and the bottom surface cannot move freely, which may cause the bonding between the sealant and both sides or the sealant itself to be damaged. Therefore, when using sealant, the bottom of the gap must be embedded with a circular polyethylene foam strip 1-2mm wider than the gap.

3. Paper tape: In order to avoid contaminating the surfaces around the joint when applying primer and extruding sealant, paper tape must be attached and torn off after the construction is completed.

4. Primer: Use a brush to apply primer to the adhered surface to increase the bonding between the sealant and the building materials.

5. Fill the sealant: Align the front end of the sealant barrel with the seam, cut off the barrel head with a knife according to the size of the seam, and squeeze the sealant with an extrusion gun to completely fill the seams and corners. Be careful not to mix in air bubbles and use it as soon as possible once opened.

6. Finishing: After filling, use a spoon or scraper to press the sealant into the seam. If the construction tools are wetted with soapy water, the construction surface will be more beautiful. Remove the paper tape when finished.