What is the construction process for water-based acrylic protective topcoats?

　　The core construction process for water-based acrylic protective topcoats is “substrate preparation → coating preparation → application and painting → drying and curing.” Throughout the entire process, both environmental conditions and construction details must be carefully controlled to ensure optimal paint film performance.

　　1. Pre-construction preparation

　　Substrate Preparation: First, remove impurities such as oil stains, dust, rust, and old paint layers from the substrate surface. For metal substrates, the rust removal standard must reach Sa2.5 (or manual rust removal grade St3). For concrete substrates, the moisture content must be reduced to ≤10%, and the pH must be ≤10.

　　Environmental Control: Maintain the construction temperature between 5℃ and 40℃, with relative humidity no higher than 85%. Avoid construction in rainy weather, during strong winds, or under direct exposure to intense sunlight.

　　Paint Mixing: After opening the container, stir thoroughly until well mixed. If the viscosity is too high, you can dilute it with deionized water (the dilution ratio generally should not exceed 10%). After stirring, let the mixture sit for 5–10 minutes to allow bubbles to dissipate.

　　2. Coating application

　　Application methods: Brushing, roller coating, or spraying (either air spraying or airless spraying is acceptable) can be used. Among these methods, spraying offers the highest efficiency and produces a more uniform paint film.

　　Coating thickness: The recommended dry film thickness per coat is 30–50 μm. When the total designed thickness is to be achieved, apply the coating in 2–3 coats.

　　Recoating interval: At room temperature (25℃), the next coat can be applied once the surface has dried. The minimum interval is 4 hours, and the maximum interval should not exceed 48 hours. If the interval exceeds this limit, the substrate must be sanded before applying the next coat.

　　3. Drying and Curing

　　Drying time: Surface dry in 1–2 hours (25℃); fully dry in 10–24 hours; complete curing takes 7 days (curing is faster at higher temperatures).

　　Maintenance requirements: During the curing period, avoid contact between the paint film and water, oil stains, and sharp objects. Do not subject the surface to high-intensity friction or direct sunlight for 7 days.

　　4. Post-construction treatment

　　Tool Cleaning: Immediately after construction, rinse brushes, rollers, spray guns, and other tools with clean water to prevent the paint from drying and caking.

　　Coating Inspection: If issues such as sagging or pinholes occur, they must be sanded and repaired before the coating is fully dry. In severe cases, the affected area should be removed and reapplied.