Abstract: A continuous soap skimmer arranged to skim a light phase foamy or viscous material from a heavy phase liquid, the soap skimmer comprising a top float arranged to float partially or completely submerged in the light phase material, and a bottom float, arranged to float completely submerged in the light phase material, or partially submerged in the heavy phase material. The bottom float is further constructed to have a flow pipe mounted therein which is maintainable under a negative pressure. The top and bottom floats are sealed and arranged to remain afloat in their respective light and heavy phase materials despite ballasting fluctuations due to light phase material filling the soap flow path and despite variations in the densities of the respective phases. The skimmer will not sink when filled with the heavy phase liquid, nor will the skimmer weir float above the light phase material under any operating conditions.