The inside edges should be caulked the place they meet The bottom to forestall sand from receiving beneath, but your longest side that's closest would be the facet receiving removed after you demold. It can be achieved by making use of a skinny layer of plaster and smoothing it

  If this takes place it is alleged the combination has "snapped" and is also Commonly as a result of employing aged item or various forms of weather (humidity or scorching days could cause plaster to established more quickly). The miters with the angles are finished off wit