Which type of sealant is known for being non-paintable and attracts dust over time?

Silicone sealant is characterized by its non-paintable nature, meaning that once it has been applied, it cannot be covered by paint without risking adhesion issues or compromising the seal's integrity. This property makes silicone a popular choice in many applications where a flexible, water-resistant seal is desired. However, because it does not accept paint, any surrounding surfaces need to be prepped meticulously to match the final appearance of the project.

Moreover, silicone tends to attract dust and dirt over time, which can detract from its appearance and may require periodic cleaning to maintain aesthetics. This accumulation of dust is due to the inherent properties of the silicone itself, which can have a tacky surface that collects particles from the air.

In contrast, other types of sealants like latex and acrylic can be painted over and do not typically have the same issue with dust attraction. Polyurethane sealant, while also flexible and durable, generally allows for painting, which does not contribute to dust accumulation in the same way as silicone. Therefore, understanding these characteristics reveals why silicone is the correct choice in this context.