1. Coating Spray Gun Usage Methods

(1) Add the appropriate thinner to the primer to adjust its viscosity, generally to 20-30 seconds. Mix the color paint and hardener according to the instructions, and let it sit for 5-10 minutes before spraying. If the spraying viscosity needs adjustment, add the corresponding thinner. The working viscosity should be adjusted to 16-20 seconds. For gloss varnish, adjust the viscosity to 10-14 seconds. If it's too thick, the spray will have large particles, and if it's too thin, it will easily run and affect the next step.

(2) The air pressure should be controlled between 0.3-0.4MPa. Low pressure leads to poor atomization and surface defects; high pressure results in running and excessive mist, wasting materials and affecting the operator's health.

(3) The spray nozzle should be kept 200-300mm from the surface. Too close causes running; too far results in rough spots. The distance should be adjusted based on the type of coating, viscosity, and air pressure. For slow-drying coatings, spray from a farther distance; for fast-drying coatings, spray closer. The adjustment should be within a range of 10-50mm for best results.

(4) The spray gun can be moved up and down, left and right, at a uniform speed of 20~30cm/s. The nozzle should be kept perpendicular to the surface, avoiding angled spraying. The spray gun's movement speed is crucial. If too slow, the coating will be thick and drip; if too fast, the coating will be thin. The recommended speed is between 900 and 1200mm/s for general spraying.

(5) When spraying, the next layer should overlap the previous one by 1/3 or 1/4 to avoid missing areas. After each layer, spray the next one. For slow-drying paints, use the first air setting to dry the previous coat before applying the next. Primer is generally sprayed 2-3 times, then sanded with 400-grit paper. After cleaning, the topcoat is applied until fully covered. Finally, apply a gloss varnish for the complete finish. Wet sanding can be done with P1500~P2000 paper, or dry sanding with P1000-P1200 paper using a dry sanding machine, followed by polishing.

(6) When spraying outdoors, pay attention to wind direction (avoid working in strong winds). The operator should stand with the wind direction to prevent mist from blowing onto the freshly applied coating and causing a rough surface.

(7) The spraying sequence is: start with difficult areas, followed by easy ones; inside first, then outside; high areas first, then low; small areas first, then large. This avoids the mist from later spraying affecting already applied coatings.

2. Coating Spray Gun Usage Precautions

1. Method 1 – Filling Paint: When using the spray gun, ensure that the paint is fully mixed and then pour it into the spray cup. Seal the cup to prevent evaporation of the paint.

2. Method 2 – Spraying: Keep a distance of approximately 20cm between the spray gun and the surface being coated. Ensure the spray is even and the speed is consistent for uniform coverage.

3. Method 3 – Cleaning: After each spray session, clean the spray cup thoroughly. Disassemble the spray gun, pull the trigger, and clean any remaining paint inside.

4. Method 4 – Maintenance: After cleaning, lubricate the spray gun with some oil for smoother operation and longer life.

3. Mengneng Technology

Mengneng Technology is a company specializing in the sales, design, and application of coatings. We specialize in the EMI industry, industrial equipment manufacturing, bridge steel structures, petroleum, petrochemicals, specialty gas industries, power plants, wind power, and hydropower energy sectors. Mengneng provides comprehensive services, including recommending appropriate coating solutions during the design phase, delivering high-quality products and services during cooperation, and offering on-site technical guidance and excellent after-sales support.