I would suggest that for an easy low cost etching tank, go to a thrift store and purchase a suitable sized crock pot .? Make sure it is a ceramic one .? They are not affected by Ferric Chloride , have a built in heating element .? I store mine , an 8.5 qt oval one , outside under a cover to keep the weather out .? Use an oval or round unit , the rectangular ones have cracking issues .? For long term use (leaving the etchant in long term , you may need to replace the screw in the center of the clear glass cover with a titanium one , and the seal around the lid with one made from some slit gas line of epdm rubber hose .? I suggest filling with water , to the desired level , and time it for how long it takes to reach your desired temperature with the desired amount of liquid .? I would expect that ceramic would also stand up to HCL and peroxide also .? I am currently working on an idea of using a motor such as a vibrating unit as a cell phone has , for agitation rather than bubbles , but I haven't decided yet .??
