A wet etch system comprises an etching bath comprising an etching solution in a process tank inside an overflow tank flowing over an open top into the overflow tank. The etching bath has a top cover, a gas inlet, and a gas outlet above the etching solution. A gas flow system pumps inert gas into the gas inlet and extracts the gas through the gas outlet under positive pressure. The gas flow system may also bubble inert gas through the etching solution via injectors of a gas sparger in the process tank. A recirculation path connects a liquid outlet port coupled to the overflow tank to a liquid inlet port coupled to the process tank. A pump drives the etching solution to flow from the overflow tank, through a degasser in the recirculation path, back into the process tank, and overflow from the process tank into the overflow tank.