There are a few factors that can lead to a streaky finish on the surface of cured epoxy. Under most circumstances, a thin flood coat of epoxy can fix this if the streaks are due to a surface texture. If the streaks are visible, with varying appearance, you may need to sand or grind away the streaky epoxy material, and reapply a flood coat to give a better finish. For instances where there is a swirly surface texture from contaminants or poorly mixed epoxy, the surface should be sanded prior to applying a flood coat of epoxy.