Cutting and Cementing PVC Pipe,
Ducting, Tubing and Fittings
Measuring: When sizing a length of pipe, measurements should be taken from the base of the pipe-stop on the inside of the fitting. As each section of ducting is cut, it should be dry fitted before the next measurement is taken.
Cutting: The pipe should be cut as straight and square as possible. A mitre box should be used if available. All rough edges must be removed with a utility knife or coarse sand paper.
Dry Fitting: Once all the pieces are cut they should be dry fitted to check for correct fit. The markings on the fittings can be utilized to assure proper alignment.
Gluing: PVC solvent cement actually welds the fitting to the tubing. A chemical reaction permanently joins the molecules from each surface to produce an airtight seal.
Before cementing, both the ducting and the fitting must be free of PVC burrs, dirt and grime. The components should be wiped with a clean cloth if necessary. Cement should be applied to the pipe only as cement applied to the fitting will be pushed ahead and create a rough bead on the inside of the fitting. This bead will reduce airflow and could cause a clog. The tubing should be inserted all the way into the fitting and twisted a quarter turn to evenly distribute the cement. All excess cement should be removed with a rag. The glue should be allowed several hours to set before the vacuum system is used.