When using hydroxypropyl methylcellulose (HPMC) as the main additive for interior wall putty powder, the details and precautions during the construction process directly affect the construction quality and effect. HPMC, as a water-soluble cellulose derivative, is widely used in building materials, especially in putty powder. It can significantly improve the construction performance of putty, such as thickening, water retention, extending the open time, and improving adhesion.
1. Environmental requirements
Temperature and humidity control:
The temperature and humidity of the construction environment have a great influence on the construction effect of putty powder. Generally, the construction temperature should be kept between 5°C and 35°C, and construction should be avoided at extremely high or low temperatures. In a high temperature environment, the drying speed of putty powder is too fast, which may cause cracking and poor adhesion; while in a low temperature environment, the putty powder may not be fully cured, affecting the construction effect. When the humidity is too high, the drying time of putty powder is prolonged, which may cause the surface to be wet, affecting the later construction and decoration effects.
Surface cleaning:
Before the putty is applied, the wall should be clean and free of dust, oil stains or other pollutants. Pollutants can affect the adhesion of putty and the uniformity of the coating, causing it to fall off or be uneven.
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2. Preparation and mixing of putty powder
Mastering the water-powder ratio:
Mix according to the water-powder ratio recommended in the product manual. Too much water will dilute the putty powder, resulting in insufficient filling capacity and reduced adhesion; while too little water will affect the fluidity of the putty powder and make construction difficult. Generally speaking, when using HPMC, the water retention of putty can be increased, making it easier to operate during construction.
Fully stir:
The prepared putty powder should be fully stirred to ensure uniformity without particles and avoid agglomeration. Use a stirrer or electric mixer to stir, usually for 5 to 10 minutes. Unevenly stirred putty powder will lead to uneven construction and even affect the final effect of the wall.
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3. Construction skills
Spreading order:
When applying putty powder, follow the top-down order to avoid sagging and uneven coating. The thickness of each scraping should be uniform, avoiding too thick or too thin. For walls with large cracks, it may be necessary to fill them first and then scrape and apply the whole surface.
Use of scraper:
Choose the appropriate scraper and tools, and apply the scraper according to the wall conditions. During construction, you can use a combination of wide scrapers and small scrapers. The wide scraper is used for large-area construction, and the small scraper can be used to handle the corners and edges. The angle of the scraper should be kept stable to avoid ripples or uneven accumulation.
Coating thickness:
The coating thickness of each layer of putty should be controlled between 1mm and 2mm to avoid applying too thick a layer at one time, resulting in uneven drying or cracks. Usually, multiple thin coatings are required during construction, and after each coating, you need to wait for the putty to dry completely before proceeding to the next step.
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4. Drying and polishing
Drying time:
The drying time of each layer of putty depends on the ambient temperature and humidity and the coating thickness. Generally speaking, at a temperature of 25°C, the drying time of putty powder is 24 hours. If the environment is humid or cold, the drying time needs to be extended to ensure that the putty is completely dry before polishing.
Sanding:
After the putty is dry, use sandpaper to sand the wall to remove surface unevenness and flaws. When sanding, first do rough sanding, then gradually use fine sandpaper for fine sanding to ensure that the wall is smooth and delicate. After sanding, clean the wall and remove dust before proceeding to the next step of painting or decoration.
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5. Precautions
Avoid repeated water addition:
During the construction process, water should not be added repeatedly to adjust the consistency of the putty powder, especially during the same batch of construction. Repeated addition of water will not only affect the performance of the putty, but also cause cracks after the putty dries.
Check the adhesion:
After the construction is completed, a slight pull test can be performed on the wall to check whether the adhesion of the putty is sufficient. If the putty powder falls off or peels off, it means that there may be improper operation or quality problems of the material itself during construction.
Add water at the right time:
If the viscosity of the putty powder is too high during the construction process, water can be added appropriately for adjustment, but the amount of water added should be strictly controlled to avoid affecting the construction performance of the putty.
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6. Protection after construction
Waterproof and moisture-proof:
After the putty is applied, try to avoid direct exposure to sunlight during the drying process to avoid cracks caused by too fast drying. You can keep it moist by covering or spraying to ensure that the putty layer is evenly dried.
Prevent pollution:
After the construction is completed, the wall should be protected to avoid contamination or damage to the new coating, especially during the drying period of the putty, avoid contact with moisture or oil.
When using interior wall putty powder containing HPMC, every link of the construction needs careful attention, from the preparation of materials, construction operations to later maintenance, which directly affects the final wall effect. Reasonable environmental control, correct construction methods, and sufficient drying and protection measures are the key to ensure the smooth construction of putty powder and achieve high-quality results.
Post time: Jun-12-2025