Weld-on introduces the 717 Gray Solvent Cement to create an airtight seal between your PVC pipe and PVC fittings. It works on both the PVC pipe and PVC pipe connectors and creates a watertight and unbreakable joint between them. This gray solvent cement can be used to repair loose PVC pipe fittings and PVC connectors, install new plumbing pipes, and repair small hairline cracks in your pipes.