Redox potential control is a fundamental requirement to minimize corrosion of metals in neutron irradiated molten salts, including fission reactor fuel, fission reactor coolant, and fusion reactor blanket. In this presentation, the focus will be placed upon metallic redox buffers—including beryllium, zirconium, and lithium. The study of beryllium for this function spans several decades and includes use in the Molten Salt Reactor Experiment (MSRE) in addition to proposed use in a fusion blanket. A fascinating aspect of this subject is the phase behavior of the metallic redox buffer. Evidence has been published that some of the metals—including beryllium and lithium actually dissolve into their host salts in the zero oxidation state. This provides the capability for a fast, homogenous reaction sans mass transfer limits. But redox buffering has also been reported from the reaction of molten salt with zirconium metal rods. It is proposed that these reactions can be categorized as either short range (homogenous) or long range (electrochemical cell) electronically mediated reactions. Data on metal solubility, electrochemical measurements, and corrosion control will be presented from the MSRE to very recent work in support of the Versatile Test Reactor. Open questions will be posed with the intention of encouraging the audience to propose new theories and experiments to test those theories.