During manufacture, the components of a cathode ray tube must be protected against contaminants, such as dust, that will degrade performance of the completed tube. A protective tunnel, in which a contaminant-free environment can more easily be maintained, protects open cathode ray tube funnels that are moved between a coating station and a drying oven. Access doors may be provided to allow for cleaning and maintenance of the tunnel, as well as access to cathode ray tube funnels in the tunnel. A vacuum system may also be provided to clean airborne contaminants from the protective tunnel.