Shuangyuan SY168 PU Seam Sealant for Automotive Workshops Description Shuangyuan SY168 is a practical polyurethane seam sealant for automotive body repair workshops and trade suppliers. Its 300 ml cartridge format, easy application, and paintable, sandable finish suit sheet metal seam repair and refinishing projects. Product Feature 1. Workshop Application – Suitable for automotive body seam repairs. 2. Practical Cartridge Format – Supplied in convenient 300 ml packaging. 3.