Techniques for Squarely Cutting the End of a PVC Pipe

Question

I am replacing a floor drain which required me to saw off the old drain which was cemented to 4" schedule 40 PVC. I had limited room to do this (Please see the picture below; I had broken out the concrete and gravel/earth around the drain), so I used a Dremel with a plastic cutting blade to cut from the inside of the pipe, leaving a slightly jagged pipe end. The new drain has a hub connection that fits over the end of the pipe I've cut. I've read that the end of the pipe should be as square as possible to maximize the quality of the hub connection. Right now the cut isn't square and I'm having a hard time figuring out how to make it square. As such, I have a few questions in one here, because I'm not sure what my options are.

1. How important is the squareness? If one side is off by a third of an inch or so, will this really matter once the hub connection is solvent cemented onto the pipe, considering there will still be a couple of inches or so of bonding surface?
2. If the squareness is important, what are some good ways to cut the pipe, seeing as I have very limited room to work with it from the sides?
   • I have considered sanding/grinding from above until the edge is level. Would the PVC dust be dangerous if I were applying suction from a shop vac (with a HEPA filter and dust bag) and wearing a respirator?
   • I had hopes there would be a tool that could be placed over the end of a 4" pipe and turned to make a squared-off cut. Does any such tool exist? Is there anything at all that can squarely cut 4" pipe without needing much room at the sides of the pipe?

Answer 1

There is a tool that is made for cutting out the PVC pipe in a joint so that it may be used again. That tool may be useful to square up the end of the pipe in this case if you were able to hold the tool inline with the pipe while it shaves off the high part of the pipe. This is what one example of the tool looks like.

These are used to chucking up the tool into a good sized electric drill (AC powered is recommended). The round slug on the end of the tool keeps the cutter centered in the pipe so that the cutters will shave off the PVC pipe in the coupling. In your case this may allow you to square off the pipe in your drain if you can hold the tool steady whilst it shaves off the high part.

Note that not all PVC pipe shavers are suitable to your situation. Some of them do not have the same type of round slug as shown above. Cheaper ones may just have a thin washer style guide to hold the cutter centered in the pipe. Even the above tool type may not work in your instance if the non-square end of your pipe is too angled.

When searching for these the search phrase you want is "PVC fitting saver".

Answer 2

Being that you are repairing an unpressurized drain, the squareness of the pipe end is not nearly as critical as a pressurized supply line. Just make sure to clean and prime the pipe prior to applying solvent cement. Additionally, if you have a level handy, lay it across the drain once the fitting is in place to to ensure proper placement.

Side note: It may help to know that you aren't really gluing the pipe together, but you are creating what's known as a solvent weld.

Answer 3

Well I am a guy that can't cut a straight line. For large pipe (2",3",4" etc.) one good way is to install two stainless steel hose clamps at the cut separated by the width of the saw blade. I use a wood miter saw which has small teeth and a wide blade for a clean cut.

For the situation like the bath tub drain mentioned here in use one stainless steel hose clamp and a file, sander or small saw to cut against the hose clamp. The hose clamps are somewhat self centering but can be positioned at desired marked location of the cut. The stainless steel being harder than the PVC forces the saw to the desired cut location. For smaller size pipe the handheld PVC cutters pay for themselves and take the guess work out of cutting.