This article addresses the optimization of a dosing tank using a spiral harmonic motion. The dosing tank is used for the short-term storage of cohesive sand, which is then released into a tubular mold. Originally, a solution based on the principle of wiping the material using rotary blades and brushes was used to fill the molds. However, this method was not effective enough. This solution suffered from uneven dosing as well as loss of material. The mold filling time ranged around 20 seconds. During the course of optimization of the dosing tank, a new design of the tank was created and external energy in the form of harmonic spiral vibrations was introduced into the system. The chosen shape of the harmonic spiral motion proved to be the most suitable for the continuous emptying of the cohesive sand from the dosing tank into the tubular mold in a very short time. There was also a significant elimination of material losses. It was determined, that the frequency of harmonic motion affects uniform dispensing of material from tanks.