Professional Tips on Cold Weather Painting
What to do and what to avoid when painting in cold weather
Painting in cold weather or during winter is sometimes unavoidable. Many homebuilders and remodelers try to get everything done by the end of the year but sometimes timing is just not right.Cold weather might be referred as temperatures ranging between 35 to 50 degrees Fahrenheit. So, how to paint in cold weather? If you don’t have any other option, try following these tips.
How to Paint in Cold Weather: The Facts
It is important to understand how really low temperatures can affect paint application and how it changes the drying pattern, characteristics and performance of the paint.
Cold weather affects painting because alkyd and oil paints are based on natural oils and resins that at low temperatures become more viscous. So when painting in cold weather, or even at subzero temperatures, some paints, will become very thick or semi-solid that might require excessive thinning. However, latex paints will freeze at low temperatures, requiring some special additives to improve freeze/thaw resistance in paints. These same additives could be used for hot weather painting making easier the brushing and rolling process. Latex paints are affected solely by the slower evaporation rate of water and volatile additives at low temperatures.
How to identify If the Paint is No Longer Usable?
Latex paints, as we explained earlier, might freeze and thaw, if they are not treated properly. Nonetheless, how can you paint if the product has gone through several freeze/thaw cycles? If that’s the case, and if you are planning to use that old latex gallon, you might want to check if the paint has become lumpy.
When such consistency is observed, the paint is no longer usable and must be discarded. Latex paints are manufactured to undergo a limited freeze/thaw cycles, but at this moment that paint should be discarded. Latex-based paint will freeze at the same temperature as the water while oil-based paint will be more resistant will freeze at lower temperatures.
How to Paint in Cold Weather: Recoat
Cold weather will slow drying time and will extend your recoat times. Recoat time, using latex paints, at 75 degrees Fahrenheit requires a period of four hours. If the temperature drops to 50 degrees, then the recoat time will be extended to six hours. Painting in cold weather using alkyd paints will require even more time, in some instances more than 48 hours before recoating. It is important to note that the surface temperature can vary between different areas on the same structure causing the dry time and proper film formation to vary as well.
Some of the results that you might get when painting in cold weather will be:
- Film Cracking
- Poor Touch Up
- Inadequate stain resistance
- Color Uniformity Issues
Problems During Cold Weather Painting
Painting in cold weather might bring additional problems such as:
- Poor color uniformity
- Heavy film might slow down drying period
- Paint will require more mixing time
- Water spotting problems, especially Latex paints
- Improper film formation causing a powdery film
- Touch up coat might look lighter than the base coat
- Excessive film building up might reduce your paint coverage
- Oil-based paint should not be applied when temperature is below 40 degrees
- If the room temperature is raised to create better environmental conditions, premature skinning of the surface might occur
- A latex paint film that goes under freeze-thaw cycles during the first two weeks of cure may shorten the long-term life of the paint system.
How to Paint in Cold Weather Tips
If you have no other choice, than to paint in cold weather be sure to:
- Verify that the paint manufacturer recommends the paint for your specific temperatures
- Check the wall’s temperature with a non-contact infrared thermometer, too, not just the air temperature
- Turn up the heat as it will help your paint on getting dry
- Choose the right roller and brush depending on the temperature and paint consistency.
- Paint between 10 a.m. and 2 p.m., light on clear cold days will help you on getting a better view
- Set up scaffolding, wrap everything and heat the area.
- Use cold weather coatings and do not paint if the temperature will be below 35° F for two days after painting.
- Make sure you use a good bonding primer before applying paint.