Emulsion paint is widely used for its versatility and ease of application. However, homeowners often encounter issues when applying emulsion paint over different types of surfaces or previously painted walls. This article discusses common problems with emulsion paint and provides practical solutions.
Problem: Crazing or Cracking of Emulsion Paint
One common issue is the appearance of a ‘crazed’ or ‘crazy paving’ effect on walls after applying emulsion paint, particularly when painting over a different type of paint, such as silk with matt emulsion.
Potential Causes and Solutions
- Painting Matt Over Silk: Applying matt emulsion over silk paint can lead to crazing. This is due to the differing properties of silk (flexible and shiny) and matt (less flexible and flat) emulsions.
- Solution: Sand down the silk paint to break its surface, allowing the matt emulsion to adhere without crazing. Alternatively, apply a coat of Dulux Trade Acrylic Eggshell before the vinyl matt to ensure better adhesion.
- Environmental Factors: Warm temperatures can cause paint to dry too quickly, potentially leading to a crazed finish.
- Solution: Avoid painting in excessively warm conditions or direct sunlight. If unavoidable, thin the paint slightly to slow down the drying process.
- Quality of Paint: Using very thick or high-quality vinyl matt paint without thinning can lead to flaking and crazing.
- Solution: Thin the paint before application, especially if using high-quality Dulux Trade Vinyl Matt, to ensure a smoother finish and prevent crazing.
Problem: Removing Crazed Emulsion Paint
In situations where crazing has already occurred, simply applying more coats is often ineffective.
Solution
Soak the affected paint area three times with warm water (with intervals of 5 minutes) and then scrape off the softened emulsion, similar to stripping wallpaper. Clean the walls with a sponge as you go. Once removed, prepare and repaint the surface as recommended.
Preparing for Repaint
- Proper Surface Preparation: Before repainting, ensure that the surface is properly prepared. If applying silk over silk, wash down the walls with diluted sugar soap, let dry, lightly sand the surface, dust off, and apply a neat coat of silk.
- Choosing the Right Undercoat: In case of a significant color change or when painting over shiny surfaces, use a matt emulsion as an undercoat before applying the final silk coat. In some cases, water-based masonry paint can be used as a first coat to ensure adhesion.
- Professional Advice: For complex issues or when unsure, consulting a professional painter or a reliable paint supplier is recommended.
Conclusion
Crazing in emulsion paint is a common issue, often due to incompatibility between the new and old types of paint or rapid drying conditions. Proper surface preparation, choosing the right type of paint, and following the correct application techniques can prevent such problems. If crazing occurs, the affected paint must be removed and the surface properly prepped before repainting. With the right approach, emulsion paint can provide a durable and aesthetically pleasing finish.
