Vitreous enamel coat, organic coating system, adhesion, surface treatment

The contribution deals with study of adhesion organic coating systems for the repair of a damaged vitreous enamel coat. Vitreous enamel is resulting product of the physiochemical reactions in the process of heat glass forming of the complicated chemical constitution with next components of the inorganic character and connecting nesting characteristics of the glass and ceramic with ability of the adhesion to metal. Damage of the vitreous enamel coat arises particularly during of transport the product and its handling and assembly of enamelled parts for agricultural, energy and water industry. For experimental works were used two types of coating systems on the basis epoxy concrete resin and polysiloxane. Experimental results show that the vitreous enamel coat can be repaired by the above-mentioned organic coating systems. According to the results of adhesion tests according to EN ISO 16276-1 (Pull-off Test) and EN ISO 16276-2 (Cross-cut Test), the adhesion of organic coatings on vitreous enamel coat is suitable in value in the range from 4.0 to 5.2 MPa (according to Pull-off Test) and degree classification in the range from 0 to 4 (according to Cross-cut Test and according to pre-treatment of surface vitreous enamel coat). Use of thus repaired vitreous enamel coat is limited by the properties of the organic coating in contact with aggressive corrosive environment, temperature, drinking water and food.