Devices, systems, and methods of improving paste flow during the manufacture of wind turbine blades are provided. When the first turbine blade half is aligned with the second turbine blade half, a gap is formed between the first shell and the bond cap. The assembly includes a first mold half corresponding to the first turbine blade half and a second mold half corresponding to the second turbine blade half. When the first mold is aligned with the second mold, a second gap is formed. A first barrier is disposed within the first gap and a second barrier disposed within the second gap thereby fluidly sealing a volume defined by the first gap and the second gap to direct adhesive paste flow along the blade span between the adjoining leading and trailing edges.