HfB2-15 vol% SiC prepared by field-assisted sintering was oxidized at 2000 deg. C by heating in a zirconia-resistance furnace and by direct electrical resistance heating of the sample. The morphology and chemistry of the oxide scales were examined and compared. In addition, limitations of the materials and the direct electrical resistance heating apparatus were explored by heating samples multiple times and to temperatures in excess of 2300 deg. C. Oxide scales that developed at 2000 deg. C from both methods were similar in that they consisted of a SiO2/HfO2 outer layer, a porous HfO2 layer, and a HfB2 layer depleted of SiC. But they were very different in scale thicknesses, impurities present, scale morphology/complexity. Possible test artifacts are discussed.