Bgcoop8784;975899 wrote: I just started using the primer in the past few years, I've done a lot of plumbing without it, but I figure it can't hurt. It softens up the pvc a little to allow the glue to react better. The main thing is to use glue on both pieces so that the pcv slides together easier, and also a little twist helps, then as Rich said hold it for a few seconds in place. Also don't take too long between putting the glue on and putting the pipes together, have all your parts laying right in front of you before putting any glue on. Just be warned, if you get the purple primer.....plan on having purple hands no matter how careful you are it will happen.