The paper is a presentation of a study on issues concerning degradation of protective paint coat having an adverse impact on aesthetic
qualities of thin-walled cast-iron castings fabricated in furan resin sand. Microscopic examination and microanalyses of chemistry
indicated that under the coat of paint covering the surface of a thin-walled casting, layers of oxides could be found presence of which can
be most probably attributed to careless cleaning of the casting surface before the paint application process, as well as corrosion pits
evidencing existence of damp residues under the paint layers contributing to creation of corrosion micro-cells