Weather plays a big part in the success of any painting project. You already know it’s never a good idea to paint in the rain, but what about the sun?
You cannot paint in the sun due to the UV rays and the higher surface and air temperature. Although paint will dry faster under such conditions, there will also be problems such as bubbling, flaking, and chalking.
This article will tell you everything you need to know about painting in the sun and how it affects the drying process, and curing. Let’s get started!
Can You Paint or Spray Paint in Direct Sunlight?
You should not paint or spray paint in direct sunlight. Sunlight can heat the surface of the building, leading to poor paint adhesion. Most exterior paints should be applied at 50°F to 90°F (10°C to 32°C) depending on your specific paint brand.
Also, the direct impact of sunlight can increase the surface temperature of the house by 10°F to 20°F (-12°C to -7°C). This means that even if it’s 70°F (20°C) outside, it’d be too hot to apply paint if the sun is out, as the surface would be too hot.
If you want to know whether it’s safe to apply exterior paint under direct sunlight, do this simple test courtesy of Consumer Reports: Touch the surface of the building for a moment. If it’s too hot to touch, it’s too hot to paint. (source: Consumer Reports)
Therefore, you should paint only when the area to be painted is away from direct sunlight or is cool (and safe) enough to touch.
The USDA Forest Service recommends starting with the east side of the building in the morning, moving around to the south, and then the west in the afternoon. You can paint the north side of the structure at any time since it never gets direct sunlight. (source: USDA Forest Service)
How Long Does Paint Take To Dry in the Sun?
Paint can take around 1 to 8 hours to dry in the sun depending on the type of paint you use. For example, water-based paint will dry much faster than oil-based paint. The thickness and color of the paint will likewise affect how long it takes to dry.
Let’s go in-depth into the factors that affect how long it takes for fresh paint to dry:
- Type of Paint: Under direct sunlight, latex (or water-based) paint will generally be dry within an hour of painting. On the other hand, oil-based paint will take 6-8 hours to dry under the same conditions. (source: Do It Yourself)
- Thickness: The thicker your coats of paint, the longer they will take to dry. So, if you’re working on a spray paint project and want it to dry ASAP, keep the spray gun on a low setting to apply thinner layers of paint.
- Color: Darker colors of paint absorb heat more than lighter colors do, so they’ll dry much faster in direct sunlight. You should note that white paint is the least affected by sunlight since it reflects it.
Although it seems that it’s better for the paint to dry faster, this isn’t actually the case. If the paint dries too quickly, it won’t bond to the surface correctly. Drying too quickly can also result in temperature blisters or bubbles, which must be sanded and repainted.
- Bubbling: Paint contains a solvent that evaporates as the paint dries. If the paint dries too quickly and the solvent doesn’t evaporate, it gets stuck under the paint and causes bubbles. (source: The Spruce)
- Flaking: If the surface is too hot when you apply the paint, it won’t adhere properly to the surface. This can cause the paint to peel or flake off even after a couple of years or so. Meanwhile, a well-applied paint job will last 10-15 years on a building.
- Chalking: When exposed to too much UV light, paint can develop a thin layer of powder. Also, oil-based paints are much more vulnerable to chalking. (source: Lowes)
All these issues will require you to sand and repaint the entire area. That’s why it pays off to paint it right the first time around.
Besides, don’t let a quick-drying surface fool you. Even if your first coat of paint feels dry to the touch, you should wait about an hour before applying the next paint coating. That way, you don’t trap any moisture between the layers and cause the problems noted above. (source: M Brett Painting Company, Inc.).
One top-rated paint brand is the Montage Signature Interior/Exterior Eco-Friendly Paint (available on Amazon.com). You can find it in a variety of colors, and you can apply it to both the interior and exterior surfaces of your home.
Also, it’s eco-friendly, and if you’re not happy with how it turns out during the first few years, you can take advantage of the manufacturer’s 10-year warranty.
Will Paint Cure Faster in the Sun?
Paint will cure faster in the sun. But if paint cures too fast, it will jeopardize the paint job’s longevity. Curing occurs when the layer of paint forms a film and hardens completely. The paint will feel dry before it is completely cured.
If your paint doesn’t cure properly, it won’t last long. (source: Dunn-Edwards Paint).
The time it takes for paint to cure depends primarily on the paint you use. Oil-based paint takes a week to cure, while water-based paints take a month (source: Glidden).
It’s not practical to wait for ideal weather conditions to paint all the time. However, choosing a time when the paint can dry and cure properly will make a big difference.
I hope this helps when you’re next thinking about painting on a sunny day (or not!)