"Sand art is the practice of modelling sand into an artistic form, such as a sand brushing, sand sculpture, sandpainting, or sand bottles. A sand castle is a type of sand sculpture resembling a miniature building, often a castle.
The two basic building ingredients, sand and water, are available in abundance on a sandy beach, so most sand play takes place there, or in a sandpit. Tidal beaches generally have sand that limits height and structure because of the shape of the sand grains. Good sculpture sand is somewhat dirty, having silt and clay that helps lock the irregular-shaped sand grains together.
Sand castles are typically made by children, simply for the fun of it, but there are also sand-sculpture contests for adults that involve large, complex constructions. The largest sand castle made in a contest was 18 feet tall; the owner, Ronald Malcnujio, a five-foot-high man, had to use several ladders, each the height of the sand castle. His sculpture consisted of one ton of sand and 10 litres of water to sculpt.
Sand grains will not stick together unless the sand is reasonably fine. While dry sand is loose, wet sand is adherent if the proper amounts of sand and water are used in the mixture. The reason for this is that water forms little "bridges" between the grains of sand when it is damp due to the forces of surface tension. However, if too much water is added, the water fills the spaces between the grains, breaking down the bridges and thus lowering the surface tension, resulting in the sand being able to flow more easily and the structure collapsing. According to the BBC TV programme Coast, the ideal ratio is eight parts dry sand to one part water (though this may depend on the type of sand). However, recent research has found that the optimal sand-water mix for building sandcastles contains 1% water by volume. (The same researchers also found that it is possible to build sandcastles underwater.)
When the sand dries out or gets wet, the shape of a structure may change, and "landslides" are common. Furthermore, the mixture of fine (mostly sharper) and coarse sand granules is very important to achieve good "sand construction" results. Fine granules that have been rounded by the natural influences of seas, rivers or fluvials, in turn negatively influence the bonding between the individual granules as they more easily slide past each other. Research is thus necessary to find the most suitable sand to achieve an optimal, landslide-free construction.
Shovels and buckets are the main construction tools used in creating sand castles and sand sculptures, although some people use only their hands. Water from the sea to mix with the sand can be brought to the building site with a bucket or other container. Sometimes other materials, such as pieces of wood, are added to reinforce structures.
Sand sculpting as an art form has become very popular in recent years, especially in coastal beach areas. Hundreds of annual competitions are held all over the world. Techniques can be quite sophisticated, and record-breaking achievements have been noted in the Guinness World Records. Sometimes, contests are staged as advertising or promotional events.
Some sandcastle artists are purists, using no artificial materials, formwork, coloring, adhesive or heavy machinery. However, in sand-sculpting competitions, the rules often require that the finished sculpture be sprayed with a stabilizing coating that preserves it and allows the work to be properly judged and enjoyed by spectators. This coating is often a simple mixture of environmentally friendly wood glue and water. Coated sculptures can last for months.
Since 1989, a World Championship in Sand Sculpture has been held in Harrison Hot Springs in Harrison, British Columbia, Canada, also known as "Harrisand". The competition has solo, double and team categories. The world's tallest sand castle was built on Myrtle Beach in South Carolina as part of the 2007 Sun Fun Festival. The structure was 49.55 feet (15.1 m) high. It took 10 days to construct and used 300 truckloads of sand.
An annual competition is held on Hanalei, Kauai, every year. This is the main sandcastle/art contest in Hawaii.
On September 1, 2007, Ed Jarrett completed his world-record 31.8-foot (9.66 m) high sand castle, at the Point Sebago Resort in Casco, Maine. The Castle to the Sun was constructed to raise funds to benefit children at Camp Sunshine on Sebago Lake. He created a 29′3′′ (8.9 m) sandcastle in Falmouth, Maine, in 2003, declared the world's tallest.
Fort Myers Beach, Florida hosts two major sand sculpting events each year. The American Championships, in its 27th year held in November is the largest in Florida and Sand Bash, in its 5th year held in April was the first Master/Professional sand sculpting contest dedicated to women.
An annual competition is held on Siesta Key, Florida, every year. Its fine, white quartz sand regularly wins comparison rankings of beach sand, yet complex structures are built during the competition.
The dune sands of Lake Michigan offer ample opportunity for Great Lakes area sand fanatics of all ages to enjoy building castles in the sand. In 2013 the Friends of the Fort Gratiot Lighthouse and The Sand Lovers hosted Michigan's first Master/Professional sand sculpting competition, "The Blue Water Sand Fest" was a huge success and will continue in years to come.
Each year in June residents and visitors of the Grand Haven, Michigan area have enjoyed building art in the sand at the Sand Sculpture Contest, held annually at Grand Haven City Beach. A new annual event dubbed Castle Grande promises to build the biggest sand castle Lake Michigan has ever seen. The premise is to harness the energy of an entire beach going community to focus all their efforts on piling sand high and wide to build a singular grand sand castle." Wikipedia