Is there something mixed with the sand?
There is nothing but water mixed with the sand. The sand is particular type of sand that fits into creating sculptures. The sculpture is finished by spraying it with Finnish Kiilto 66 yleis-/puuliima glue-water mixture to get its hard surface.
What happens when it rains?
Normal rain does not hurt the sculptures. It here is a continued heavy rain, the surface of the sculptures may be hurt and the we will make repairs on them.