John has it right. There is not one brand that has proven to be immune to zinc pest. They have all had it somewhere sometime in recent memory. This is the price we are paying for having everything made in China. Their zinc foundry industry has no QC and does not care what goes in the pot, so long as it melts. If companies want to solve the problem, they need take the zinc casting business elsewhere. Of course, the product will cost more, because all the molds stay in China, so new ones will need to be designed and fabricated. Then there is the higher cost of quality raw materials, and the QC that goes into them. Then add in the skilled labor with accompanying higher wage. So pay cheap (a relative term) now and big later (presuming one can even find the parts), or pay big now and little or nothing later.