Attraction time for capillary rafts*

Particles on an air-water interface can spontaneously aggregate due to a phenomenon often referred to as "the cheerios effect". Although the attraction of individual particles has been well studied, the interaction of between rafts at the air-water interface is less understood. Here we aim to predict the time it takes for two rafts to come together given their size and separation. Using a combination of experiments and modeling, we find that the merging time follows an exponential scaling that varies between two asymptotic limits based on the size of the rafts relative to the capillary length.