Teila,
Thanks again for the information and reply! I would think a 300 series stainless material would work well. 400 series definitely no which is typically used in home grills for the barbie. I have found them to start corroding within a couple of years without salty air! You can source home brewing pots on the internet as an option. Insert some nipple feeders and make a stand for supporting it above your chickens and that may solve your problem. I prefer a permanent solution. If I spend $20 to $40 on a waterer every 1 to 2 years it does not take long to pay for a higher end stainless system. If you are handy this may be the easiest solution for you. Our RH in the mid-west USA was between 65% and 85% for northern Illinois where we completed 3 years of testing. No issues with mold. temps were similar to yours, also both higher (105F) and lower (-20F). Our annual rainfall was about 36". In the Rockies we have tested the system for an additional 3 years with RH closer to below 35%, rainfall near 16" annually, however temps between zero F and prolonged periods between 95 to 105 F. Our system would also solve your problem I believe. One avenue to market I am considering is to offer a license to build one yourself when you purchase the plans for a nominal fee. If you are moderately handy this could be an option. You would have the option to source the critical parts from us also.