Posted by Chris A. on February 20, 2005 at 11:52:33:
In Reply to: Cold Galvanizing paint worthless posted by Dave on February 18, 2005 at 11:59:22:
You are right that hot dip is better then applying zinc paint. But the cost to hot dip just one tank is more than a steel 72 is worth. The zinc based paint is good enough and you'd typically overpaint it with good quality top coat of plain old white paint. The purpose of the zinc coating is not to exclude water contact from the steel so a scratch is acceptable. Two dissimalar metals in contract
in a conducting medium (like saltwater) makes a
battery
Even using paint is expensive. The best quality marine grade polyurathane is $20 a qt. It is as good as the stuff Faber uses but one qt. is enough for 5 tanks. Same with the zinc.
Yes I do believe in hot gip. I had all the custom Iron work at my house (2nd floor balcony rails and the like.) trucked out to Fontanna and run through a big hot dip facility out there. It's cheaper to replace the tank unless you need to dip a truckload of tanks