Spraying water-based lacquer involves proper preparation, setting up your spray gun correctly, and mastering the spraying technique to achieve a smooth, even finish.
Spraying water-based lacquer effectively requires controlling your gun angle, distance, and fan pattern based on the surface area.
Understanding Water-Based Lacquer
Water-based lacquer is a durable, fast-drying finish that uses water as its primary solvent. It's known for being less toxic and easier to clean up than traditional solvent-based lacquers. However, it dries very quickly, which requires careful spraying technique to avoid lap marks and inconsistencies.
Essential Steps for Spraying Water-Based Lacquer
Achieving a professional finish with water-based lacquer depends on several key steps, from preparing your workspace to mastering the spray gun technique.
1. Preparation
Proper preparation is the foundation for a good spray finish.
- Surface Preparation: Ensure the surface is clean, dry, and smooth. Sanding, filling imperfections, and removing dust are crucial. For previously finished surfaces, assess compatibility or sand down to bare wood if necessary.
- Thinning (if needed): Check the manufacturer's instructions. Some water-based lacquers may require thinning with water or a specific additive to flow properly through the spray gun, especially with smaller tip sizes.
- Setting Up Your Area: Work in a well-ventilated area, ideally a spray booth or outdoors. Protect surrounding areas from overspray using drop cloths or plastic sheeting. Maintain a consistent temperature and humidity level as recommended by the product manufacturer.
2. Spray Gun Setup
Selecting and setting up your spray gun is critical for achieving the correct atomization and pattern.
- Choose the Right Equipment: HVLP (High Volume Low Pressure) or airless sprayers are commonly used for water-based finishes. Select a tip size recommended for lacquers (often in the 0.010 to 0.015 inch range for airless, or specific fluid tips for HVLP).
- Adjust Pressure: Follow the manufacturer's guidelines for your specific spray gun and lacquer. Too little pressure can result in poor atomization and spitting; too much can cause excessive overspray and runs.
- Adjust Fan Pattern: Test your spray pattern on a piece of scrap material. Adjust the fan width and fluid flow until you achieve an even, consistent pattern without heavy edges or a split pattern. On large flat areas, use wet, even patterns 6 to 8 wide. This helps cover the surface efficiently with minimal overlap lines. For narrow surfaces, reduce the fan pattern to 2-3" to reduce overspray and better control the application on edges, spindles, or narrow boards.
3. Spraying Technique
Consistent technique is vital for a smooth, even coating.
- Maintain Angle and Distance: Keep your gun at a 90* angle to the surface at all times. This ensures the lacquer hits the surface evenly. Keep your gun... 6-8" from the surface. Maintaining this distance helps the lacquer atomize correctly and lay down smoothly without drying too fast or building up too heavily.
- Use Consistent Strokes: Start spraying off the piece, move across the surface at a consistent speed, and stop spraying off the piece. Use smooth, overlapping passes (typically 50% overlap) to ensure complete coverage without streaks.
- Handle Different Areas: As noted, adjust your technique for the specific part of the project you are spraying.
- Apply Multiple Coats: Water-based lacquers typically require multiple thin coats rather than one thick coat. Allow adequate drying time between coats (check product instructions), and lightly sand between coats if necessary for adhesion and smoothness.
4. Cleaning Up
Clean your spray equipment immediately after use with water, following the manufacturer's instructions for your specific lacquer and spray gun. This prevents the lacquer from drying inside the equipment, which can cause blockages and damage.
Tips for Success
- Temperature and Humidity: Pay attention to the environmental conditions. High heat and low humidity can cause water-based lacquer to dry too quickly, leading to issues like dry spray or poor leveling.
- Test Spray: Always test your setup and technique on scrap material before spraying your actual project.
- Wear Protective Gear: Use a respirator, safety glasses, and gloves to protect yourself from airborne particles and chemicals.
By following these steps and paying close attention to your technique, especially maintaining the correct gun angle, distance, and adjusting the fan pattern as needed, you can achieve excellent results when spraying water-based lacquer.
