Testing the zinc coating
While the zinc coating are tested in accordance with WTWiO, the following methods to be applied.
Checking the appearance of the coating.
- This checking should be done with a naked eye. The appearance of the surface shall meets all requirements pointed in a paragraph "Appearance of the coating on products that meets requirements for elementary zinc coating".
Checking the thickness of the coating.
- The thickness of the coating to be checked with a special unit for measuring the non-magnetic coatings that doesn't destroy them.
Checking the adherence of the coating
- The applied technology ensures enough strong adherence and it isn't a subject of additional checking. However, if cracks are observable or the Customer requests the checking the adherence, such testing to be carried out with a hammer in accordance to the BN-80/1904-12 Standard.
- The surface shall not chip or rise when treated by hammer during the checking the adherence.
Repair the zinc coating
Even the process is carried out most carefully, local damages or too thin coating can not be avoided (e.g. at a point of application an elevator). Since they're caused by The Hot Galvanizing Plant, it will repair them, since they're caused by constructional errors, the competence and covering the expenses of such reparation to be agreed between both parties.
A total surface of all repaired places may not be bigger than 0,5 % of the total surface of product.
An individual surface of one repaired place may not exceed 100 cm^(2) .
Caution: The places free from the zinc coating, when it's caused by improper technological preparation of the product can be protected against corrosion on the Customer's request, only:
- with an aluminum-zinc spray (protects against rust by a cathode method)
- with a quick-drying acrylic lacquer for esthetics improvement.
If the product will be painted with powder after the hot galvanizing, The Plant have to be informed about this fact before the treatment.
