The surface coated goods are finished with certified façade polyester powder paints for use on aluminium and galvanised steel components. The qualitative assessment of the coated parts is governed by the GSB standard or Qualicoat Class 1. The standard scope of the coating of visible surfaces on the individual structural parts is defined in the technical manual. The holes necessary for hanging the parts during coating are defined here.
Observe the prescribed distance during visual inspection of the goods. This distance is 3 m in the case of the exterior structural parts and 2 m for the interior structural parts. Inspection of the exterior coat quality is done in diffused daylight while inspection of the interior coating is done using normal light intended for use in the rooms (not light strips or targeted lighting). The viewing angle is perpendicular to the surface.
Thickness of coat layers:
The standard thickness of the coat should be between 50 and 120 μm. For objects directly exposed to the marine climate, it is recommended to apply two layers in the interest of achieving the minimum coat thickness of 80 μm at the edges and corners.
Colour shade deviations:
Powder coats are made and their recipes are compiled according to the defined RAL colour standards. In spite of the most meticulous working methods, it is not possible to completely eliminate colour shade or effect deviations in the case of various manufacturing batches. During manual spraying, it is necessary to count of fluctuation of the colour shade and effect due to the
unequal application of the powder coat layer.
Large orders of same colour and batch, which are processed in multiple coating plants, may have
potential colour shade and effect differences due to the varying processing parameters and equipment types. The different types of spray guns and equipment parameters and application are often the cause of the different results.
Additional bending and re-coating or final coating:
If additional shaping of a coated part is to be done, it is necessary to first test this procedure directly on the original parts because the microscopic cracks that occur in the powder coat layer during shaping may result in corrosive damage.
Adhesion of sealants, adhesives and foam products:
During the application of sealants, adhesives or foam products, it is necessary to clean the coated surfaces in an appropriate manner, for instance, using Isopropyl alcohol. It is recommended to do a preliminary test and it is also necessary to obey the recommendations of the suppliers of the above-stated products. Even short-term use organic solvents, for instance, nitro solvents or acetone, just like the use of alkaline, abrasive or other cleaning products that damage the coat leads to irreversible damage in the coat layers that is not discernible with the naked eye.
Packaging of coated parts:
Suitable packaging materials must not contain softening agents. The impact of condensed moisture (for instance, under the packaging foils) and heat in unsuitable storage conditions particularly in the exteriors may cause milky white blotches.
Storage of coated parts:
Protect the packaging from sunlight, humidity and dirt. Ensure proper ventilation to prevent condensation. Open the foil on the front side to allow ventilation of the objects packed in the foil. Secure the items in the open boxes to prevent damage from storms.
Cleaning – façade:
The pre-condition for optimal treatment of the coated construction part is its regular cleaning at subsequent intervals at least once per year, and more often in case of higher load (according to the guidelines of the Institute for cleaning of metallic façades – GRM). Cleaning must be done by a member of the GRM Institute using permitted cleaning agents and aids according to RAL-GZ 632-1996. Do not use aggressive or corrosive agents. When cleaning, use only soft non-fraying fabrics. Avoid excessive rubbing. Do not use steam cleaners. Wash the surfaces with clean cold water immediately after cleaning. Even short-term action of organic solvents such as solvents, acetone, principles or acids, corrosive or other cleaning agents, which damage paint, may cause irreversible damage to the paint surface, which is not visible with the naked eye.