Sand all edges of glass with emery paper. Glass is cleaned with acetone (nail polish remover)or methyl hydrate (gasline antifreeze) to remove all traces of oil. Large glasses are taped 3mm apart, siliconed, folded and placed on end with 60 degree angle. silicone is applied to end edges and an end plate is placed on the fresh silicone. Allow to dry. Place assembly on other end glass and mark outline. Apply silicone to second end of assembly and apply end plate, taking care thae edges that form the bottom support of the water prism are parallel. allow to dry and apply a second layer of silicone along inside of seams to ensure water tightness.