SPRAY PAINT

Sagging

Causes: Applying too thick a layer at once, or spraying too close to the workpiece.

Solutions:

1. Apply in small, multiple coats: Follow the principle of "thin coats, multiple layers." Apply only a thin layer each time, wait a few minutes for it to surface dry before applying the next layer.

2. Maintain distance: Keep the nozzle approximately 15-20 cm away from the workpiece.

3. If sagging has already occurred: Do not attempt to wipe it off immediately. After the paint has completely dried, lightly sand it smooth with fine sandpaper (e.g., 1500-2000 grit), then reapply a thin coat.

Rough Surface or Particle-like Texture

Causes: The workpiece surface was not properly cleaned, or dust from the air settled on the undried paint.

Solutions:

1. Thorough Cleaning: Before painting, thoroughly wipe the workpiece with a degreaser or alcohol, and remove dust with a tack cloth or tape.

2. Dust-Free Environment: If operating indoors, spray a little water mist into the air first to allow dust to settle before starting work.

3. Backspray Cleaning: After spraying, invert the can and press the nozzle a few times until a clear gas is emitted. This prevents the nozzle from clogging and causing particles to be sprayed next time.

Whitening or Loss of Gloss (The paint surface has a white haze and lacks shine)

Causes: Excessive air humidity, or moisture in the compressed air used for spraying (if using a spray gun), causing condensation in the paint film.

Solutions:

1. Check the weather: Avoid spraying when relative humidity exceeds 80% or on rainy days.

2. Heating: If the environment is cold, soak the paint can in warm water (note that the water temperature should not exceed 40 degrees Celsius, and never use an open flame) to increase the pressure inside the can and make the paint mist finer.

Uneven Color or Exposed Base Coat (Underlying Color Visible)

Causes: The paint is applied too thinly, or no primer was used.

Solutions:

1. Use Primer: When changing a dark color to a lighter one, or painting on metal/plastic, always apply a coat of a dedicated primer first.

2. Cross-hatching Method: Apply the first coat horizontally, then the second vertically. This results in more even coverage.

Blistering (New paint causing the underlying paint to blister and wrinkle)

Cause: The solvent in the newly applied paint is too strong, dissolving the old paint layer.

Solutions:

1. Sand the old paint: Before spraying new paint, the old paint surface must be roughened with sandpaper (to increase adhesion and seal the old paint).

2. Ensure complete drying: Ensure the underlying paint or primer is completely dry.

Summary: The "Golden Rules" of Perfect Spray Painting

1. Pre-treatment accounts for 70%: Sanding smooth and removing oil and dust are key to success.

2. Thin coats, multiple coats: It's better to apply 3-4 thin coats than one thick coat.

3. Suitable environment: Temperature 20-25℃, humidity below 70%, and a windless or slightly windy environment are ideal.

4. Post-treatment: After painting, invert the can to clean the nozzle; this extends the can's lifespan.