What's the common problems during using the Polyurethane waterproof coating?
There are 4 common problems during using the Polyurethane waterproof coating
1.One-component polyurethane coating film has no strength?
The coating film will not have strength if it is not completely cured and dried. The surface dryness of polyurethane does not mean that the coating is cured. The coating film will only have strength after it is completely cured. Or inappropriate additives are added to the coating, causing the coating film to lose its original strength after curing. material properties.
2.One-component polyurethane bulging or base layer peeling off?
Reason: The base layer is wet with water or contains volatile solvents, which will cause swelling when volatilization occurs. Floating dust and sand on the surface of the base layer will cause the coating film to fall off.
Solution: Before applying the polyurethane coating, ensure that the base layer is dry and free of oil. If there is floating slurry or dust on the surface of the base layer, use a wire brush to polish the floating slurry and use a hair dryer to blow away the floating dust.
3.Does polyurethane develop skin after opening the barrel?
Reason: The packaging barrel is deformed or damaged, causing a chemical reaction between the material in the barrel and the moisture in the air, causing skin to form on the surface of the material. After the polyurethane package is opened, the material needs to be used up within 1 hour. If the exposure time is too long, surface crusting will occur.
Solution: After the surface of the material in the polyurethane bucket is crusted, peel off the surface crust. The lower coating can continue to be used as long as it is not cured.
4. Is the surface of the polyurethane coating film scratched or cracked?
Reason: After the polyurethane coating is painted, the interface agent is used to roughen the coating before it is completely cured. The polyurethane coating has not yet fully reacted, and there is still solvent oil attached to the surface. At this time, roughening will cause cracking and hollowing.
Solution: After the coating film is completely dry, completely polish off the cracked and hollow interface agent on the surface of the coating film and re-nap it.
How to solve the problem of high viscosity of polyurethane?
Polyurethane is a one-component solvent-based coating with high viscosity and difficult construction. It is recommended to use a scraper to apply it, but roller coating or brushing is not recommended. In addition, thinner can be added to the paint. Before use, a test must be done. Use a small amount of sample to paint, check the film-forming effect and quality, and then use it in large quantities after passing the test.