Problem Using Polyurethane Waterproof Coatings!

Question 1: One-component polyurethane coating has no strength?

If the coating film is not completely cured and dried, it will not have strength. The surface drying of polyurethane does not mean that the coating is cured. The coating film will have strength after it is completely cured, or inappropriate additives are added to the coating, which will cause the coating film to lose its originality after curing. material properties.

Question 2: Is the one-component polyurethane bulging or the base layer falling off?

Reason: the base layer is wet with water or has volatile solvents, which will cause bulging when volatilized, and the coating film will fall off when there is floating ash and sand on the surface of the base layer.

Solution: Make sure that the base layer is dry and free of oil pollution before applying the polyurethane coating film. If there is laitance or floating ash on the surface of the base layer, use a wire brush to polish the laitance, and blow the floating ash with a blower.

Question 3: Skinning phenomenon occurs after the polyurethane is opened?

Reason: The packaging barrel is deformed or damaged, resulting in a chemical reaction between the material in the barrel and the moisture in the air, resulting in skin formation 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, the surface will be crusted.

Solution: After the surface of the material in the polyurethane barrel is crusted, peel off the crust, and the lower coating can continue to be used as long as it is not cured.

Question 4. Is the surface of the polyurethane coating rough and cracked?

Reason: After the polyurethane coating is painted, the interface agent is used to brush the coating before the coating is completely cured. The polyurethane coating has not been fully reacted, and there is still solvent oil attached to the surface. At this time, the brushing will cause cracking and hollowing.

Solution: After the coating film is completely dry, completely polish off the interface agent roughening of the cracked hollow on the surface of the coating film, and then re-brushing.

Extra gift: 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 scraper coating, not roller coating or brush coating. In addition, diluents can be added to the paint, and a test must be done before use. Brush with a small amount of samples to check the film-forming effect and quality of the paint film, and then use it in large quantities after passing the test.

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