Plumbing Chemicals

Solvent cements, primers, thread sealants, PTFE tape, flux, cleaners and cutting oil — the consumables a rough-in actually runs out of.

Solvent cement is matched to the pipe, not chosen by preference. PVC cement will not bond ABS, ABS cement will not bond PVC, and CPVC needs its own formulation rated for the higher service temperature. Transition between materials with a mechanical coupling or a listed transition cement, never by mixing the two.

Most inspectors look for purple primer on PVC and CPVC because it is the only visible proof the surface was cleaned and softened before the cement went on. Clear primer exists for exposed work where the stain is unacceptable, but it removes that proof — confirm it is accepted locally before using it.

Keep flux off potable joints once soldering is done. Residual flux is acidic and will keep attacking copper from the inside; flush the line. And check the shelf life stamped on the can — cement that has thickened in an opened container no longer makes a rated joint and thinning it does not restore one.