The most common reason to paint storage tanks is to repair their protective coatings. The current coatings may deteriorate from exposure to the sun and overall weather. There are times when the facility is refurbished with a new look and color theme. There is a need to paint storage tanks to make them blend with the new surroundings. Painting is also done to place liquid level markings on the tank exteriors, or when the company logo has to be displayed prominently in the tank’s outer surface.
What are the basic elements to successful tank painting? There are three:
1. Proper paint selection
The most common products used to paint storage tanks are acrylic-based coatings or elastomeric formulations. Acrylic paints are fast-drying high-quality paints containing acrylic polymer emulsions. They are extremely water-resistant and are more longer-lasting than ordinary paints. They exhibit excellent adhesion to any surface and are very reliable in tank surfaces.
Elastomeric paint is known as the best exterior finish paint. It is highly-resistant to the sun’s rays, driving rain, and changing temperatures and humidity. Elastomerics form a strong film that serves as a good waterproofing system. They are compatible to nearly all types of surfaces.
2. Good surface preparation
To paint storage tanks successfully, surface preparation should be done properly. Particularly for new tanks, the surface preparation should be doubly careful. Good paint adhesion is only possible with a surface free from any foreign contaminants.
New tanks have smooth surfaces initially. This smoothness should be removed to increase the adhesion profile of the tank’s surface, giving way to a rough and dull surface area. Why is a dull surface better for surface adhesion? It’s because the roughened surface profile creates a stronger bond between coating and surface.
Surface preparation may either involve sand-blasting the surface with a sand-blaster or by hand, or flame-treating it with a propane torch or flame gun to remove the glossy appearance. Care must be taken when doing the second method.
3. Correct application
The equipment and techniques that can be used to paint storage tanks are the same standard tools used in other painting applications like exterior or interior walls painting, floor coating, and the like. The skills of the painting contractor, the availability of quality paint, and the surface properly prepared — make the application process go smoothly and finish successfully.
All other factors come down to the actual moment of painting the surface. To paint storage tanks successfully means only one thing — a good adhesive bond. Applicators must often be on the lookout if the coatings product failed to adhere properly. Thin coats are applied carefully and repeatedly to assure effective adhesion. This method to paint storage tanks is time-consuming, but has to be done because tanks have a much smoother surface than regular surfaces. The different surface tension is the reason for the more careful and therefore slower application process.
Storage tanks are structures known for their robustness and longevity if they have been built correctly and to specifications. Tank coatings play a major role in their protection and in prolonging their useful service life. When time, the elements and daily operations lead to gradual deterioration of the coating system, facility managers must prioritize resources to paint facility storage tanks.