Abstract: An assembly for applying hot melt adhesive to the backbone of a book block to attach a cover includes a bath of hot melt glue heated to approximately 350.degree. F. A metal wheel is submerged in the bath. The metal wheel is rotated and scrapers meter the hot melt adhesive on the surface of the metal wheel. The metal wheel transfers the hot melt adhesive to flexible adhesive distribution wheel. The flexible wheel is fabricated of a silicone rubber with iron oxide capable of withstanding the elevated temperatures of the hot melt adhesive while maintaining its flexibility. In addition, the cut and mold of the wheel results in greater flexibility of the wheel, allowing the wheel to flex to engage completely the backbone of each book block to apply the adhesive fully and completely.