Dry surge ropes are typically used in VPI (vacuum pressure impregnation) systems and provide support for the windings in motor applications. These round ropes are comprised of either texturized fiberglass cores with a fiberglass overbraid or polyester, including the option of an aramid fiber core. - The untreated fiberglass version is rated as Class C (over 240 °F), but the end use rating will depend on the resin used for impregnation. Continuous lengths or special sizes are available upon request.