The similar results could be noticed after manual polishing of the surface. In the technology processed in NTP company, the
effectiveness of vibro-abrasive machining as the basic method for preparation of cast surfaces before
plating process was used and verified. To verify the obtained results, the tests determining an influence of
individual processes on the quality of the obtained coatings were performed. The main variable was the
surface preparation method i.e. condition after casting, grinding, polishing and vibro-abrasive machining.
The tests showed that the surface condition directly after casting is not suitable for galvanic plating. It is a
result of pores and contamination having negative influence on the properties of galvanic coatings
connected mainly with adhesion reduction. The tests performed on the polished casts also showed a low
suitability of that type of initial machining for plating the magnesium alloys. After process, number of
surface defects and contamination on the surface of the polished elements were noticed. The third type of
machining involving grinding the cast surfaces, regarding quality of galvanic coatings, was better than
previously discussed ones. However, it also showed essential defects. They resulted mainly from the
process unrepeatability and possible removal of the skin layer, which uncovered internal porosity of casts.