he effects of flow velocity and surface temperature on batch autoxidation fouling were studied using model solutions of indene in an inert lubricating oil using an annular fouling probe where Re ranged from 3000-6500 and T-surface ranged from 180-255 degrees C. Chemical initiation was used to overcome difficulties observed in thermally initiated runs. Fouling occurred in two stages : (a) an initial, linear fouling rate which increased exponentially with temperature and decreased as Re increased, consistent with a boundary layer reaction deposition mechanism; (b) a subsequent, accelerated fouling stage involving bulk mass transfer control. These mechanisms were also observed in model solutions of hexadec-1-ene and dicyclopentadiene in Paraflex. The effectiveness of an antioxidant, 2,6-dibutyl-4-methylphenol (BMP), in mitigating autoxidation fouling decreased markedly when exposed to temperatures above its ’ceiling’ temperature in the fouling loop. The antioxidant had little effect on autoxidation and fouling after the BMP was exhausted.