Open end or dr ain hole at the correct position and size If no lug is possible opposite holeing will be required for jigging Center hole dr ainage is not recommended ZINC Zinc run Residual zinc Suggested design for flanged hollow sections A Optional hole position Preferred filldr ain hole position B V ent hole Filldr ain hole C V ent hole D Optional hole position Preferred vent hole position E Open end fulldr ain facility V ent hole prevents air tr aps and resulting ungalv anized internal areas or even floatation Larger opening for faster flow of zinc into unit VENT HOLE CORRECT AIR Incorrect vent hole AIR T r apped zinc sloshes out and runs solidify during cooling causing heavy unsightly buildup from incorectly positioned hole Zinc Correct dr ain hole Zinc will flow around and down circular units leaving dr ainage runs along units V ent and dr ain holes too small V ent and dr ain hole size V ent and dr ain holes that are too small in hollow sections increase immersion time and may cause unsightly excessive zinc dr ainage runs as the zinc freezes during the dr aining period Space matching surfaces Do not forget to vent and dr ai hollow sections Avoid welding units back to back Suggested design 24