Abstract: A method of and apparatus for the immersion treatment of discrete lengths of galvanized conduit to inhibit the formation of "white rust" on the conduit surfaces are disclosed. The conduit is continually conveyed successively through three treatment zones comprising a cleaning bath containing a cleaning agent which removes lubricating oils, greases, dirt and the like from the conduit interior and exterior surfaces, a rinse bath and a coating bath containing a coating agent including chromate ions and a polymeric coating composition. A rotary star wheel-type conveyor is arranged in each treatment zone for transporting the conduits in spaced, substantially parallel relation to each other about an arcuate path through each bath and for inclining the conduit above the bath for a time effective to drain excess liquid from the interior and exterior conduit surfaces. Effective draining of excess liquid prior to entry to another zone minimizes contamination of the various baths and yields a high quality product.