I've been retrofitting an existing PVC irrigation system around my house. Part of that work requires that I work in shallow holes adding T joints and elbows in places where there were none before. In an effort to measure twice and cut once, I've been assembling the system without glue to make sure I have the layout correct. More often than not however I'm running into issues separating the slip joints and pipes despite the fact they aren't yet glued.
What's the best way to separate these joints? Should I be applying some sort of lubricant beforehand (that won't affect gluing later on) or is there a trick beyond forcing things? With too much force I'm afraid I'm going to break pre-existing joints or mangle the existing fittings.
Best Answer
The best lubrication I've found is some good ol' Elbow Grease™.
Actually, you should measure the proper lengths and just cut. Then glue it up and install. You can mark on the PVC how far it should go into the fitting if you want to be really precise. However PVC itself expands and contracts a lot with temperature change and is fairly flexible anyway. So, in my opinion, being extremely precise doesn't mean all that much anyway. Also, The solvent melts the PVC surface to weld them together, so the fittings will likely fit differently while gluing, thus making the dry-fit method even worse than just measuring.
Another solution could be to mark how far in the fitting the piece should go and lay them next to each-other in that position, even tape them together, to check your layout. That seems pretty time-intensive, though. I still think it would be better to just measure accurately and double check your measurements.