Our daughter just bought a van conversion camper that has a fiberglass roof. She wants to install a CB radio with a mag mount antenna. She is willing to install a 6" X 6" metal plate for the magnet mount; however, she needs a ground plain. Would it be feasible to weld four, 1" flat bars to the metal plate to give her a workable ground plane on a fiberglass roof? If so, how long would the flat bars need to be?