I would suggest slushing a layer of Rondo Mud in your armor, letting it almost cure, then putting fiberglass cloth down on the still-tacky mud (It should stick there pretty easily) and slushing another layer of mud. Should be really strong, and shouldn't take too much time. Plus, you won't have to form the glass to sharp details, as the first layer fills them. However, you get added strength from a layer of rigid glass.