By establishing a direct electrical current between electrodes in an electrolyte like seawater, brine or brackish water, calcium carbonates, magnesium hydroxides, and hydrogen are precipitated at the cathode, while at the anode, oxygen and chlorine are produced. The electrochemical precipitation of minerals at the surface, to form a coating, or internally, to mineralize, of organic fibrous material, such as wood, is utilized to prevent attack by fouling and boring organisms, and to improve structural characteristics of the material. To provide a mineral coating on a structure made of a fibrous material, one or more cathodes are inserted in the structure, which is disposed in an electrolyte such as seawater, brine, or brackish water. One or more anodes are disposed in proximity to the structure, and a direct electrical current is established between the electrodes for a period of time sufficient to coat the structure and/or mineralize the fibrous material.
A method of, and apparatus for, making a synthetic breakwater involves the steps of arranging flat, approximately parallel electrodes (20 and 22) which are approximately coextensive with one another, so that they are spaced from one another by electrically insulative materials (10) with a gap of from 3 cm to 27 cm. An electrical potential is applied across these electrodes to cause a current density flowing between the electrodes of not greater than 0.1 milliamps (ma) per cm.sup.2. In the preferred embodiment, the electrodes are spaced approximately 5 cm apart and a voltage of around 3 volts is applied thereacross. The flat cathode is of expanded electrically-conductive metal, with the anode being constructed of two materials, one of them being an outer casing (30) of lead.
