Fiberglass fillers are known to be what?

Fiberglass fillers are particularly recognized for their waterproof properties. This characteristic makes them highly effective in automotive applications where moisture can be a concern, such as in body repairs that are exposed to the elements or in areas prone to water damage. The waterproof quality helps prevent rust and corrosion, extending the life of the repair and maintaining the integrity of vehicle components.

While options like flexibility and lightweight may describe other materials used in auto body applications, fiberglass fillers are specifically noted for their ability to resist water absorption. This resistance is crucial in ensuring that the repairs made with fiberglass fillers last and perform well over time, demonstrating their superior durability when compared to other fillers that may not have the same waterproof qualities.