For a mist coat on new plaster, you should add water to your paint in a ratio of three parts paint to one part water. This thinned-down emulsion acts as a primer, allowing subsequent coats to adhere properly.
Understanding the Mist Coat
A mist coat is crucial for painting new plaster because plaster is very porous and will absorb paint unevenly, potentially leading to a poor finish and wasted paint. The watered-down paint penetrates the plaster, sealing it and creating a stable base.
Mist Coat Ratio: Paint to Water
| Component | Ratio | Example (1 Litre Total) |
|---|---|---|
| Emulsion Paint | 3 parts | 750 ml |
| Water | 1 part | 250 ml |
Alternatives to Watering Down Paint
While watering down emulsion paint is the standard practice, you can also use a dedicated plaster sealer. Dulux Sealer for Plaster is one such product. Follow the manufacturer's instructions for application. Using a dedicated sealer offers consistency and may be preferable for those less confident in mixing the mist coat themselves.
Important Considerations
- Type of Paint: Use a standard, matt emulsion paint for the mist coat. Avoid using vinyl or silk emulsions, as they may not adhere properly to the plaster when diluted.
- Mixing: Thoroughly mix the water and paint to ensure a consistent solution.
- Application: Apply the mist coat evenly with a roller or brush. Avoid applying it too thickly, as this can cause runs.
- Drying Time: Allow the mist coat to dry completely before applying subsequent coats. This may take several hours, depending on the humidity and temperature.
By following these guidelines, you can effectively prepare your new plaster for painting and achieve a professional-looking finish.
