RTV Silicone Rubber Coatings for Outdoor Insulators: A Concise Review of Some Factors Affecting their Behavior and Some Comments

Traditional outdoor insulators are made of glass and porcelain. However, although such insulators have been used for many decades, they present some drawbacks. Glass and porcelain insulators seem to be more prone to surface discharges and flashover when they age and water droplets are more likely to spread on their surface, causing thus dry zones and consequently conditions for surface discharging and flashover. Room Temperature Vulcanized (RTV) coatings spayed on the aforementioned traditional insulators seem to remedy such problems because such coatings increase the hydrophobicity. In this paper, a short review on RTV coatings is given together with some thoughts and comments regarding the so-called early stage of aging.