Copper sheet
Sheet copper is a material made by rolling . It is used for covering roof surfaces , roof drainage or for roof plumbing work . Gutters and downpipes can be made from sheet copper , but also weather valves and seals. Copper sheets are very popular with builders and architects due to their durability of over 200 years.
The bare metal copper forms an oxide film of copper (I) oxide in dry air within a few hours , which is not yet noticeable to the naked eye. This film noticeably stabilizes the surface of the copper against the effects of the atmosphere. The slow development of the oxide layer as a result of the reaction of the copper with moisture, atmospheric oxygen and aggressive air constituents gradually results in a uniform brown color; the surface of the copper increasingly loses its metallic luster. The brown becomes darker and darker and turns into anthracite brown over time. This is generally the final color state on vertical building surfaces, such as external wall cladding. In the case of sloping roof surfaces, the color of the protective layer continues to change until the typical copper patina green is achieved. The reason for this further development is the longer retention time of precipitation on sloping roof surfaces and the associated increased formation of basic copper compounds.
This is not what is known as verdigris , which is only produced in connection with acetic acid , which does not occur in the atmosphere. Verdigris would also be water-soluble and could therefore not take on the protective function of the protective layer.
Due to the good thermal conductivity, thick copper sheets were used to make pans and pots. Copper pipes and large copper vessels are still used today in distilleries, breweries and for cheese-making on a large scale.
If you have a copper and a zinc sheet in a mild acid (for example citric acid appeared), one obtains a galvanic element which exactly 1 volt voltage generated.
Individual evidence
- ↑ Thomas Ludwig: Copper and zinc removal from rain runoff from roofs in an iron corrosion system. Approved dissertation at Faculty III - Process Sciences - of the Technical University of Berlin, Berlin 2007.
- ↑ Use of copper and zinc on roofs, gutters and downpipes. (accessed on August 23, 2019)
- ↑ Chemical coloring of copper and copper alloys. (accessed on August 23, 2019)
- ^ Daniell Element. P. 37 ff. (Accessed on 23 August 2019)
Web links
- Plates and Sheets Copper Sheets (accessed on 23 August 2019)
- Discoloration of copper sheet patina, verdigris or blue-green discolouration (accessed on 23 August 2019)
- Copper sheets (accessed August 23, 2019)