How Cold Temperatures Affect Paintings: Risks and Precautions

Acrylic, alkyd, and oil paints become extremely brittle at low temperatures. Changes in temperature cause a phase change in the material, and for these paints, it is the beginning of a transition from an extremely flexible paint to a very brittle paint. At low temperatures, these paints undergo a change known as glass transition, abbreviated Tg. As the temperature decreases, there is a significant loss of elongation and an increase in the strength of the paint; in other words, the paint becomes increasingly brittle. It is low temperature that induces brittle behavior and not low relative humidity (RH). (Low relative humidity causes damage in other ways.)

Paints are prone to suffer low-temperature damage because of the glass transition temperature. The phase change or transition from a flexible paint to a brittle paint is different for different types of paint. For acrylic paints, Tg is ~ 50º to 45º F (10 to 7º C); for alkyd paints, Tg is ~ 40 F to 35º F (4 to 1º C); and for oil paints, Tg is ~ 32 F to -14º F (0 to -25º C). Acrylic paint, although more flexible at room temperature than oil paint, can readily become more brittle at low temperatures.

The lesson: Do not expose your paintings to low temperatures, especially on flexible supports, such as stretched canvas. This means protecting paintings during transport and handling where they are likely to be exposed to low temperatures.

Frequently Asked Questions (FAQs)

Is cold weather bad for painting?

Yes, cold weather can be detrimental to painting. Lower temperatures can affect paint application, drying, and long-term durability. Most paints, such as acrylic or oil-based options, require a minimum temperature of around 50°F to cure properly. Cold conditions can lead to improper curing, resulting in a weak finish prone to peeling and discoloration.

What is the coldest temperature you can paint at?

For most types of paint the minimum recommended temperature is 50°F. Below this temperature, paint may not adhere well and can have a prolonged drying time. It’s essential to check the manufacturer’s recommendations, as some paints are formulated for lower temperatures.

What temperature should you stop painting?

You should stop painting if temperatures are expected to drop below 50°F within a 48-hour window after application. This guideline helps ensure that the paint cures properly, avoiding issues related to freezing and moisture.