What Went Wrong? | Too Much Color?

A woman had her house painted in mid September with a deep, maroon colored, exterior acrylic latex stain. The weather was clear with a relative humidity of 65% (on average) during the two days of painting, and the temperatures ranged from lows of 55°F (approx. 12°C) to highs of 78°F (approx. 25°C). Two weeks later, after a day of light rain, the woman noticed that the paint had lightened and was tacky to the touch. Challenged, the painter replied that since the stain was a latex and still new, it could slightly soften when wet, but "would harden up completely in a few days".

A few days later it began to rain and continued for three days. At the end of the storm, the newly applied stain appeared washed-out in areas with many small blisters on the south exposure, and felt very soft and tacky. The woman again called the painter, who called the paint supplier, who sent a representative to inspect the house and the left-over paint.

A month later, the supplier's representative was contacted by the woman to find out the results of the inspection. She was told that there was nothing wrong with the stain, and that any problems would relate to the environmental conditions during application and curing.

Not satisfied with this answer, the woman contacted the Association. The Association assigned a certified coating inspector to examine the house and to determine the cause of the problem.

Wet samples of the stain were taken from the remaining cans, and analyzed in the laboratory. The coating had a notably long dry time, and in gas chromatographic (GC) analysis appeared to have a large amount of propylene and ethylene glycol. The stain was then further tested using mass spectroscopy / gas chromatography (MSGC). This revealed a large percentage of surfactants relative to the pigment and polymer levels. These two components led to the slow dry and to the water sensitivity of the stain.

It was ascertained that the stain was a tinted base that had 18 ounces of colorant per gallon added to it to arrive at the selected color. Where large amounts of universal colorant are added to a coating (particularly waterborne types), properties such as the dry, water sensitivity, and film integrity can be adversely affected.