What di I do if my Fiber Lok rug backing is too thick to spread? Monica P. March 03, 2020 14:44 A little bit of cold distilled water can be added to thin consistency. Related articles Fiber Lok is thick and dried out looking, Can it still be used? How do I fix my tacky and gooey surface? Can I wash and dry my rug after applying Fiber Lok rug backing? How long does it take for Fiber Lok rug backing to dry? Comments 0 comments Article is closed for comments.