It is the Dog Days of Summer and boy is it hot outside… The Heat from the direct sun can raise the temperature of a surface in excess of a 100 plus degrees.
The question is, Can you paint in this HEAT? The answer is Yes but not in the direct sunlight. When painting in direct sunlight paint separates from the surface and can form bubbles of air, these are called paint blisters.
If you are seeing blisters/bubbles on the surface recently painted, leave them alone for now. In some instances they will settle down and smooth themselves out. If the blister remains you will have to scrape off the blister and then sand down the surface to a smooth feel and look.
We recently tested a door in November on a cold morning with a Frost on the ground. We used an infrared thermometer which is a laser device pointed at a surface to read the temperature of that object.
All though it was approximately 35 degrees outside the temperature on the surface of the door in the direct sunlight was reading over 50 degrees. This showing the effect direct sunlight can have on a substrate.
A little painter’s advice. If you can avoid painting in the direct sun, avoid it. Youa re probably setting yourself up to fail.