Auto Boy Specialties is located in Middlefield, CT. This part of the United States is having quite the hot, wet, and humid summer. Our customers who spend a lot of time painting their cars are having a bit of a difficult time finding favorable conditions to paint in. Hot and humid weather can affect paint in a variety of ways. If the conditions are too hot and dry, paint can dry too fast, crack, and peel. If you’re trying to paint in humid conditions, the moisture in the air can cause the paint to dry too slow. Check out our tips this week on painting a car in hot and humid weather.

How does humidity affect automotive paint?

When the humidity in the air is high, the paint is exposed to a greater amount of water vapor. The water vapor affects the drying of the paint because the moisture mixed in takes longer to dry. If the humidity is high enough, the paint may have a difficult time adhering to the surface of the car. If you choose to paint in humid weather, you should only do so in humidity that is eight five percent or less. On the other hand, if the humidity ends up dropping below thirty percent, the paint may dry too fast. Ideally, the best humidity levels to paint a car in are forty to fifty percent.

Using different types of car paint in humid weather

The type of paint you’re using can also be affected by humidity and hot weather. Waterborne paint works best when you’re painting in environment that is seventy-five degrees. If you are painting the vehicle inside a booth, try to keep the temperature five degrees warmer than it is outside. For example, if it is eighty degrees outside, try to keep the temperature at eighty-five degrees. If you’re using a solvent-based paint, you don’t want to apply it if the temperature in your paint booth exceeds the temperature outside. If it is eighty degrees outside, your booth should eighty degrees also. Drying solvent-based paint too fast can lead to cracks, brittleness, and an all around poor paint job.

Utilizing a paint booth to paint a car.

Paint booths are an easy to way to paint a car in an environment with a controlled temperature. There are four types of paint booths, Crossdraft, Semi Downdraft, Side Draft, and Downdraft. The Crossdraft allows the air to flow directly across the vehicle that is being painted. They are economic and popular because they meet all the standards and codes for a painting facility. The Semi Down Draft operates similarly to the Cross Draft. The only difference is that incoming air comes through a small section in the ceiling. There is one main disadvantage to the Down Draft which is that the person painting the vehicle might get exposed to overspray.

The Side Draft booth creates an even airflow and draws overspray and contaminants down and away from the finish. It is the cleanest option and the most efficient. Lastly, the Downdraft creates an air pattern that runs from the ceiling to the floor. It is considered the most clean and efficient paint booth. The biggest disadvantage of the Downdraft booth is that it requires a concrete pit or needs to be placed on something to make room for the downdraft to actually function.