Protective masking device to be put on an engine block during thermally coating cylinder bores provided therein, and method using the protective masking device

摘要

A protective masking device adapted to rest on the upper surface of an engine block having cylinder bores during a thermal coating operation of the cylinder bores comprises a protective masking member having an essentially hollow cylindrical shape with an inner diameter selected in relation to the diameter of the cylinder bore to be thermally coated. The protective masking device comprises either an essentially tube shaped outer sleeve member and an insert member inserted into the outer sleeve member, or it is designed such that at least a portion of a layer or of several layers of coating material applied to the inner side of the masking device during the coating operation of the related cylinder bore is mechanically removable. Using the proposed masking device, the coating operation can be started outside the cylinder bore, without the danger that portion of the engine block or the environment is contaminated by coating particles.