Humidity for Electronics: How to Cure Paint
In any electronics-based environment, it is important to consider that the drying time of paint is completely different from the curing time. “Drying” to the point where paint can feel dry to the touch takes less time than the curing process itself, which represents when a coat of paint has reached its maximum hardness and is 100% dry. For the protection of sensitive electronic equipment and instruments subjected to paint applications, it is always best to encourage a faster paint curing process. With proper humidity control it is far easier to do so, as well as some of the following methods:
Paint Colour and Sheen
Depending on the sheen of the paint used in an area, it will take more or less time to cure effectively. Water-based and latex paints, for example, take several days longer to cure than oil-based paints. Depending on the circumstances and whether you’re using semi-gloss, high-gloss or flat paints, the curing time will vary accordingly. Additionally, it is important to consider the paint colour used, which can also impact curing times. This is because the pigmentation of some colours – such as those which are darker – acts as a barrier of sorts, letting less heat and light pass through to cure. Therefore, darker paints take longer to dry and cure effectively, especially when not met with consistent and regulated humidity control.
Consider the Thickness of Your Paint Coating
Much like the pigmentation of applied paint, the thickness of the coating can act as a detractor from the curing process, hampering progression towards 100% dryness and hardness. Humidified air has a harder time penetrating the surface, prolonging the curing process unnecessarily. The same principle applies to multiple coatings of paint – consider it the same as wearing more layers of clothing in the winter to keep the cold away from your body to remain warm. To cure paint effectively and protect sensitive electronics from damage due to damp coatings, layer your coatings as thin as possible so that their purpose remains unimpacted, which will cure far more efficiently.
Introduce Controlled Humidity to Speed Up the Process Exponentially
The most crucial element in regard to paint curing is humidity. The process of consistently humidifying a space with painted surfaces or objects will introduce the optimal amount of water vapor that they are directly exposed to. Keeping relative humidity levels balanced (40% to 60% RH) will ensure that the amount of water vapor painted surfaces are exposed to isn’t too much or too little, which could otherwise mar the finish or prolong the curing process. If effectively implemented, proper humidity control can shorten the amount of time it takes to cure paint while protecting against the compromising of coating adhesion, which would otherwise result in peeling or bubbling paint finishes.
Adjust Airflow and Temperature Accordingly
Proper airflow will ensure that the surface of a painted object is evenly dried, leading to consistent curing and optimal quality control in regard to paint finish. Additionally, as the ambient temperature of an environment lowers, it thickens the coating, which will take longer to cure. Paint also won’t adhere properly to the substrate in question when temperatures or airflow are left to be unregulated. Try keeping interior temperatures between 60° F and 80° F (16° C and 26°), when possible, to protect the coating adhesion, finish, lasting quality, and also the curing time of paint applied to a substrate.
Humidity Control and Paint Dust
In environments where paint is often applied, such as a spray booth, paint dust can collect and linger in spaces without adequate humidification. This can cause problems for sensitive electronics, especially if the conditions have too much moisture in the air (which can cause short-outs and paint coating inconsistencies). Paint application and curing environments require a delicate touch in regard to humidity control – maintaining consistent and regulated relative humidity (RH) levels will eliminate the spread of paint dust by a greater margin than simply leaving it to fester or be pumped through a ventilation system. The environment will have cleaner air. As a result, populated with fewer toxins or chemicals that could disturb the finish of curing paint as well as protect technical equipment. Additionally, electrostatic discharge (ESD) risk is reduced with proper humidity, which protects against dangerous situations that would jeopardize worker safety.
The most effective form of paint curing requires three integral aspects: Precise and consistently proper humidity control, adequate airflow and temperature regulation, and an application that allows for thinner layers to speed up the process exponentially. At Nortec, our humidification systems are purpose-built to deliver optimal indoor air moisture control as well as to encourage clean, safe, and comfortable environments in all applications. For more information on paint curing and humidification, consult our pages on humidification for the automotive manufacturing industry.