Many alloys have rare earth additions to improve their surface properties at high temperatures. In this research, it will be demonstrated that for a wide variety of alloys, a dilute aqueous solution of superficially-applied, non-continuous rare earth particles will provide similar beneficial surface properties. The thermal oxides that form after this treatment are different in structure and/or chemistry from the thermal oxides that form without this pretreatment. The ultimate protective oxide that forms is primarily a function of the alloy itself, not the rare earth material. In this way, the treatment helps the alloy to become self-protective. Improved high temperature oxidation and corrosion results will be discussed for a variety of stainless steel, superalloy, and aluminum alloys. Analytical results using SEM, XRD, and XPS will be presented. The technology allows for economical surface modification in the field and inside complex geometries.