Originally Posted by Douglas Ballard I vaguely remember reading a thread that stated the poster used hide glue to fill cracks in clock cases. I have a wall clock where the backboard is split from top to bottom.When I'm done gluing the rest of it back together I need to tackle this split.ou can fill a crack with almost anything, including hide glue. But that doesn't necessarily mean it would be the best material for the task. Originally Posted by Douglas Ballard. I vaguely remember reading a thread that stated the poster used hide glue to fill cracks in clock cases.