As a general rule with RVs, if the crack is less than one inch in length, an effective repair can likely be performed. The location of the crack, however, can determine the success of the repair. For example, if the crack originates on the edge of the glass or the corner or apex of the glass curve, it may indicate a stress crack which will require more attention. For more information on stress cracks, view this document. Have a question? Give us a call – 888.777.6778