¿Qué superficies de cobre están disponibles?

Cobre natural, cobre preoxidado y cobre prepatinado.

Cuando se considera estéticamente importante que el color de la pátina verde esté presente desde el primer momento, se dispone de procesos especiales de producción que proporcionan una superficie de cobre prepatinado para cubiertas y fachadas. Este proceso se logra sumergiendo la chapa de cobre en baños químicos.

Can patination of the copper be prevented?

Applying a lacquer is not recommended, particularly when large areas are considered. Lacquers will require regular maintenance over the life of the roof.

¿Qué tipo de bronce se emplea en las obras de arte moderno?

El bronce se ha utilizado durante siglos para crear esculturas y sigue siendo un material de referencia para las llamativas obras de arte moderno. Las aleaciones más empleadas son los bronces de cañón.

¿Se pueden recubrir las superficies de Antimicrobial Copper?

No, la propiedad antimicrobiana del cobre es intrínseca al metal por lo que para mantener la efectividad antimicrobiana NO deben aplicarse aceites, ceras, esmaltes, pinturas ni otros revestimientos.

¿Sólo el cobre puro tiene un efecto antimicrobiano?

No, las aleaciones de cobre también lo tienen. Se han llevado a cabo estudios con cobre, latones, bronces, aleaciones de cobre-níquel y aleaciones de cobre-níquel-zinc a las que también se les conoce como plata alemana o alpaca debido a su color blanco brillante, a pesar de que no contengan plata. Los resultados de estos estudios demuestran que las aleaciones con un mayor contenido en cobre inactivan los microorganismos patógenos con mayor rapidez. Las aleaciones de Antimicrobial Copper contienen más de un 60% de cobre lo que asegura una buena eficacia.

Cuando se elige una aleación de cobre para un producto es importante considerar las propiedades mecánicas que se necesitan, el proceso de fabricación y, por supuesto, el color. Las aleaciones de cobre ofrecen una paleta de atractivos colores que van desde el amarillo de los latones a los marrones oscuros de los bronces.

Does copper harden when stored for long periods of time?

Copper will not harden during storage; it does not have a shelf life.

Has copper been tested in clinical trials?

Yes. Copper surfaces have been proven to have over 90% less contamination than conventional touch surfaces in hospital trials around the world.  Trials have taken place, or are under way, in China, France, Germany, Greece, Japan, Spain, South Africa, Chile and the US.

Furthermore, in a multi-centre US trial, funded by the Department of Defense, copper surfaces were shown to reduce a patient’s risk of acquiring a healthcare-associated infection by 58%.

How can bronze works of art be protected from corrosion if they are situated outdoors?

Either by the use of lacquers, wax polishing, or both.

How can corrosion or staining of machined aluminium bronze components be avoided during shipping?

The key is to clean them thoroughly, remove water, protect them and keep them dry, so:

  1. After cleaning dry thoroughly using a dewatering fluid such as WD40.
  2. Remove displaced water with forced warm air.
  3. Coat with a protective coating such as benzotriazole inhibitor, or a block co-polymer.
  4. Pack into benzotriazole treated paper lined wooden boxes. Moisture absorbent granules may also be used to keep the air inside the boxes dry.

When unpacked, remove the coatings with a phosphoric-based solution and dry them thoroughly.

How is Bordeaux mixture prepared?

Bordeaux mixture is prepared in various strengths from copper sulphate, hydrated lime (calcium hydroxide) and water. The conventional method of describing its composition is to give the weight of copper sulphate, the weight of hydrated lime and the volume of water in that order.

The percentage of copper sulphate weight to the weight of water employed determines the concentration of the Bordeaux mixture. A 1% Bordeaux mixture, which is the norm, would have the formula 1 :1:100, the first 1 representing 1 kg copper sulphate, the second representing 1 kg hydrated lime, and the 100 representing 100 litres (100 kg) water.

As copper sulphate contains 25% copper metal, the copper content of a 1% Bordeaux mixture would be 0-25% copper. The quantity of lime used can be reduced considerably. 1 kg copper sulphate requires only 0.225 kg of chemically pure hydrated lime to precipitate all the copper. Good proprietary brands of hydrated lime are now freely available but, as even these deteriorate on storage, it is safest not to exceed a ratio of 2:1, i.e. a 1:0.5:100 mixture.

In preparing Bordeaux mixture, the copper sulphate is dissolved in half the required amount of water in a wooden or plastic vessel. The hydrated lime is mixed with the balance of the water in another vessel. The two ‘solutions’ are then poured together through a strainer into a third vessel or spray tank.

How is copper used on a farm?

Copper sulphate, because of its fungicidal and bactericidal properties, has been employed as a disinfectant on farms against storage rots and for the control and prevention of certain animal diseases, such as foot rot of sheep and cattle.

How long has copper been used in agriculture?

The first recorded use was in 1761, when it was discovered that seed grains soaked in a weak solution of copper sulphate inhibited seed-borne fungi.