Detecting Surfactant Leaching Issues on House Paint
Surfactant leaching occurs when acrylic water-based paint is exposed to rain or moisture before it has fully cured, leaving brown, milky, or oily streaks or circles on the surface. While surfactant leaching has no adverse effect on the durability of the paint, it can be unsightly and is common with thick paints and darker colors.
What Are Surfactants?
Surfactants are additives that enhance the performance of the paint, improving dry times, leveling, ease of use, and more. Each manufacturer has proprietary formulations, some more resistant to leaching than others.
Potential Dark Exterior Paint Color Challenges
Darker paint colors have more color, which makes the paint dry slower. Slow-drying exterior paint leads to added challenges when high moisture conditions are imminent. Since dark colors take longer to dry, they are less likely to cure before being exposed to moisture, making them more prone to surfactant leaching. Dark colors reveal surface imperfection the most, making leaching very unsightly.
Light Moisture Affects
Outdoor weather is dynamic and uncontrollable. When painting the exterior of a house, often new uncured paint is exposed to minor dew or moisture within the first 24 hours. So, in many cases, finding minor leaching in isolated areas is common and unavoidable when painting outdoors.
Excess Moisture
As moisture on the surfaces build, surfactants are naturally drawn out. Exterior paints that dry quickly and have fewer additives will resist leaching best. Moisture-resistant exterior paints such as BM Element Guard and SW Latitude prevent leaching issues commonly found on shutters, exterior doors, and larger surfaces such as exterior siding.
Potential rainy days and humid conditions are the leading cause of surfactant leaching. Ground-level dew, frost, and home sprinkler systems cause minor issues as well.
Resolving Thick Exterior Paint Leaching Issues
The surface type, paint color, and weather must all be considered when choosing exterior paint. Exterior paints naturally need more additives, such as propylene glycol, to help them spread, dry, and perform better, but they are more prone to leaching. However, lighter colors often used for trim make the marks less visible.
Interior Paint Leaching Issues
Painted interior walls in satin and eggshell finishes used for bathrooms suffer from leaching when exposed to too much moisture. It can cause discoloration and leave an oil-like residue on the walls.
Bathroom-specific paints are formulated to dry and cure faster, and they don’t contain additives that cause leaching, eliminating the effects of surfactant leaching.
Removing Surfactant Leaching
The chances of removing stains caused by surfactant leaching are greater when removed early before the oil-like residue dries, permanently staining the surface.
Removal Steps:
- Draw hot water into a sink and add a small amount of dish soap.
- Wipe the surface using a microfiber cloth and wipe again using a clean, damp rag.
- For exterior leaching removal, use a pressure washer or garden hose. In more extreme cases, wiping the areas with a rag is required.
- Removing paint surfactants may require cleaning the surface more than once.
Painting Over Leaching Issues
- The surface must be primed and repainted when stains from surfactant leaching are not removable.
- Priming the entire surface will prevent the stains from resurfacing.
Preventing Paint Leaching
The beauty of house painting is that little can happen that can’t be corrected, but cleaning or repainting surfaces due to water spots can be costly and avoidable.
The best way to prevent surfactant leaching is to understand what it is and what causes it. Second, product knowledge is critical to maximizing interior or exterior paint performance.
Raleigh, NC, gets a lot of rain during the spring and summer months, and as exterior house painters, knowing how to prevent and identify leaching is vital to professional results.
