If the Celestopea Project^TM planned to build the floating city out of any conventional material, it would be cost prohibitive, to the tune of billions of dollars. Fortunately, a new technology was pioneered in the mid 70’s, by a University of Texas professor named Wolf Hilbertz, that allows us to create buildings, and even artificial islands, from the minerals dissolved in sea water. It is similar to the way shellfish create their shells. This process is called by various names: Seament, Seacrete and Sea Cement being chief among them.

Everyone knows there is salt dissolved in seawater. You cannot see it in the water but you can taste it. If you put salt water in a pan and boil it away, you can see the solid salt that remains behind in the pan. In addition to salt, there are 56 other minerals dissolved in seawater including gold, silver and of great importance to us, calcium carbonate.

Calcium carbonate is the principal mineral from which shellfish create their shells. Through a process not yet completely understood, they are able to extract the calcium carbonate and other minerals out of solution from seawater and shape the minerals into the exact forms, colors and patterns we see in seashells.

In the mid 70’s Professor Hilbertz was able to somewhat duplicate the techniques of the shellfish. When he ran a small electrical current through wire mesh immersed in the ocean, he discovered the minerals dissolved in the seawater, principally calcium carbonate, would accretiate onto the wire. The stronger the electrical current, the more rapidly the minerals accretiated. Using a minimal current he was able to create a wall of calcium carbonate, one-inch thick, in just a few months. The resulting wall was structurally stronger and lighter than reinforced concrete. He went on from his original experiments to create some large structures using the Seament process.

How is this possible? In the ocean, the mineral calcium carbonate has electrically positive charged ions. Any electrical current, whether it be on land or sea, consists of the flow of ions from a positive point to a negative point. Opposites attract. When metal wire mesh is immersed in seawater, external electrical sources can be attached, which creates an electrical flow where the wire mesh becomes a negative cathode. Ions of calcium combine with ions of carbonate in the seawater to form positive ions of calcium carbonate, which is attracted to the negative cathode of the wire mesh and deposited on the mesh as a solid. As long as the external electrical current is maintained, calcium carbonate and traces of other minerals, from the seawater, will continue to accretiate and thicken on the wire mesh indefinitely. One kilowatt hour of electricity, running through the wire mesh, will extract
4.2 pounds of calcium carbonate out of the seawater and deposit it onto the wire mesh as a solid.

Seament is superior in every way to conventional concrete. It helps the environment by not needing all of the ingredients of traditional concrete. There is no sand, aggregate or endless bags of cement required. Actual Seament creations of Professor Hilbertz demonstrated that Seament is both stronger and lighter than standard concrete. Seament created in 6 weeks, on ½" wire mesh, has a breaking strength of 4267 psi, which is 20% stronger than normal concrete. If it is deposited for longer periods, it produces an even stronger Seament, with breaking strengths up to 8000 psi obtained after 1 year!

The amount of electrical current required to cause Seament to accretiate on the wire mesh is very low. Only thirty amps at six volts is needed to form a current density of 1.3 milli-amps per square inch and create a one inch thickness of Seament in approximately 6 weeks. For more rapid deposition of calcium carbonate onto the wire mesh, current densities as high as 50,000 milli-amps per square foot can be used, but the greater the current density, the weaker the Seament.

Professor Hilbertz perfected the accretiation of Seament down to exact formulas. 189 milli-amps of current density through a ½ inch wire mesh will accretiate 1/10th of an inch of Seament in 170 hours. This is an accretiation rate of .0005 inches per hour. It takes three weeks, at that current density, to fill the ½ inch gaps in the wire mesh. A kilowatt of electrical power at 12 volts will create a current density of 189 milli-amps per square foot over a total area of 441 square feet.

Unfortunately, the original work of Professor Hilbertz has not been followed up on as far as we know. Seament is still in the experimental stages and still requires more research into methods of creating very large structures such as Seadomes. This is why, in the initial phases of the Celestopea Project^TM, all of the Seadomes are built with ferrocement. This is a proven technology that has been used to build boats for over 30 years. By employing ferrocement to build the first Seadomes, the project is not delayed waiting for Seament technology to be perfected. Ferrocement is a unique substance in itself. If built correctly, it is inexpensive, will not rust, rot or corrode, it's fireproof, Toredo worm proof and can be built from materials found anywhere in the world.

As the project goes forth with ferrocement domes, we will be continuing the work of Professor Hilbertz with our own Seament experiments, such as the ones that are currently being conducted in Humbolt Bay, California.  Not only do we aspire to perfect techniques for creating large structures including artificial islands, but we also want to discover just how the shellfish do it. When we can duplicate nature's seashell miracles, then we can create Seadomes in intricate architectural patterns and brilliant color designs without wire mesh or other man-made products.