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 unrepeat ability and possible removal of the skin layer, which uncovered internal porosity of casts.