NOTE: The operator must wear rubber gloves and take care to prevent spilling any acid on himself or on adjacent wood or stonework. This is done by swabbing the surface with a cold, 5%-10% solution of sulfuric acid. Copper roofs which have weathered for six months or more should have the oxide film removed before the coloring operations start. Oxide film on the copper will cause poor adherence of the patina. If necessary, cleaning should be repeated until this condition is obtained. If cleaning has been properly done, the rinsing water will spread uniformly without beading (the formation of globular droplets) in other words, the water should wet the copper surface uniformly. Avoid cleaners which leave a coat of oxide on the copper surface.įollow cleaning with a thorough rinsing to remove all traces of the cleaning compound. Cleaners of the trisodium phosphate type should be satisfactory. However, it is always advisable, particularly if the coloring is to be done immediately after installation, to go over the surface with a commercial chemical metal cleaner. This involves removal of the residual film of oil left on copper and brass sheets from mill rolling operations, and fingerprints and dirt deposited on the surface during handling and installation.Ī few hard rainstorms may clean the surfaces sufficiently to start operations. The copper surfaces to be colored must be clean, as any dirt, oil or grease on the surface will interfere with the chemical action of the solution. These potential shortcomings should be considered when attempting to artificially duplicate a weathering process which may take from five to seven years in coastal or industrial environments, longer in rural areas, and may perhaps never develop in some climates and atmospheres.Īrtificial patinas for architectural applications such as copper roofs, grilles, and statues have an inherent requirement which dictates that the solution has to be one which can be brushed or sprayed because of the large surface areas normally involved. In artificially producing or accelerating the formation of a patina, success seems to depend on the manner in which the solutions are applied, the weather conditions under which the treatment is carried out, and perhaps most important, on the climate to which the treated surfaces are exposed.īecause of the number of variables involved, chemically induced patinas are prone to lack of adhesion, excessive staining of adjacent materials or inability to achieve reasonable color uniformity over large surface areas. The basic chloride salts of copper are not only fairly soluble, but photosensitive as well. In seacoast locations, chloride salts may form an essential part of the patina film. Carbonate and chloride salts of copper may also be present in varying concentrations. In natural patination the major coloring agent in the film is basic copper sulfate. Because of the time required to achieve this, much research has been done on artificial patination, with varying success. See all Montana Black Spraypaint colours here.The much admired natural protective coating of a blue-green patina characterizes older copper roofs, including ancient cathedrals as well as bronze statues and other copper metal surfaces exposed to the weather. High pressure / fast painting optimised.Versatile dual-pressure cans each accommodate five different caps to help you achieve pencil-thin lines with slow pressure all the way up to a 13" wide spray with high pressure. The superior can of it's class, redeveloped, high coverage matt finish colours that can be applied to any surface, winter-proof, achieving optimal performance even in cold climates.
Montana BLACK Spraypaint comes in a large range of colours and has a Matt finish. Non-scented aerosol paint made to the highest quality, health and environmental standards. Short drying time allows rapid re-application and overlapping with other colors immediately. The Nitro-Combination based formula ensures high coverage, perfect control and handling. A solvent-based lacquer consisting of nitrocellulose and alkyd resin, which dries fast due to the rapid evaporation time of the solvent used. Montana BLACK Spraypaint is the paint of choice of todays artists.
0 kommentar(er)
