With Monti Caps, people just usualy wedge them between some rocks and allow them to encrust rather than putting them on plugs. If thats what you want to do, make sure both surfaces are dry and use ample ammount of super glue GEL, thats what works best. Dont be too concerned about leaving them out of the water for a short period of time, theyre very rezilliant and arent as fragile as most people think...