Get some 1" rubber door bumpers + nuts and bolts or if you want to go fancy get some metal spikes.
Lectite: Loctite Threadlocker Blue 242 from Loctite Adhesives
blue is semi permanent, will break easily if you need to replace or remove a board, red is permanent and much harder to remove, often needing some sort of solvent to help. Just use a little dot of the stuff on the thread and then tighten the nut, it will dry and keep things together.