Floating Clay / by S T

Playful bouyant floating clay.

Playful bouyant floating clay.

I wanted a novelty item for the University of Delaware “Ag Day” to raise money for additional support of the Ceramic Department. The idea was to make shapes from floating clay and have children paint them at our ceramics booth and then take them home to decorate baths and pools.

I tried to simulate a recipe for floating clay I found in a magazine by replacing the ingredients with materials readily available in the USA. All the fired pieces sank! My “Titanic” recipe used 0.5% silicon carbide - the same percentage used in the original recipe.  Silicon carbide is the critical ingredient (it decomposes on heating to release carbon dioxide to generate a sort of volcanic pumice) so I increased it to almost 10%.

Now the frogs, turtles and water lilies float nicely!


Floating Clay Recipe

Custer feldspar

Kona F4 feldspar

Ball clay

EPK (kaolin)

Silicon carbide

Gum solution

40g

40g

10 g

10 g

10 g

5 cc