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The top of this pipe is gouged where it needs to seal with the new shower base. I need to trim off a few inches from this pipe so I can glue on a clean piece. the hole is 10" square. The pipe diameter is 2 3/8".

What's the best tool I can use that will fit in the hole.

enter image description here

Follow up, I ended up using the dremel with a diamond disk. I used a hose clamp on the pipe to keep the cut straight. Lot of great suggestions but this tool I had so no need to run out to the store. enter image description here

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11 Answers 11

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A Dremel rotary tool seems perfect for this. If you don't have one then this seems like a good chance to justify buying one as you will quickly find new uses for it. You can use it to cut from outside the pipe or even inside assuming the tool would fit. Just mark the circumference with a sharpie so that you can ensure a nice square cut. If it's not perfectly square then it's not the end of the world since the PVC coupling seats onto the pipe about an inch.

Dremel rotary tool

Not sure how far down you need to go but if you just need to fix a short imperfection then you can take a belt or oscillating sander to the top of it and remove the burrs with sandpaper.

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    Word of warning: The abrasive cutoff wheel pictured is both surprisingly versatile and frustratingly temperamental. It'll cut almost anything, including metals, basically by sanding its way through a thin kerf instead of taking big chips out. Metals usually leave a nice (enough) finish, but I often have to "clean up" plastics quite a bit, using a light touch with the same tool. But beware! If you get it even the least bit sideways, it'll shatter without warning. No need to worry about kickback, only shrapnel...
    – AaronD
    Commented Nov 11, 2020 at 23:39
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    ...Also, if you keep the surface (linear) speed up and don't shatter it, it seems to last forever, but if the surface speed isn't high enough, you can literally watch it wear down to a useless nub.
    – AaronD
    Commented Nov 11, 2020 at 23:39
  • I used a Dremel to do exactly this - I had to cut down a 6" pipe that was completely flush to the wall. Easy peasy.
    – SiHa
    Commented Nov 12, 2020 at 12:16
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When I had to do this for our basement I used an "Inside Pipe Cutter", a fancy bit that fits into your standard drill. Looks something like this:Inside Pipe Cutter

You chuck it in your drill, put the blade at the height you want on the interior of the pipe, and run the drill, cutting through the sidewalls. Won't be 100% perfectly straight unless you have a very steady hand, but for this application it doesn't need to be perfect. There are versions that have a large disk that rides along the top of your pipe to make straighter cuts, if you really think you need it. I chose the style depicted since it's commonly available at Big Blue and Big Orange

If you need to cut off more of the pipe than this tool reaches, do it in multiple passes.

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    This is hands down the very best suggestion here. Most of the other ideas are just not practical in the hole depicted in the question except for the right angle oscillatory blade.
    – Michael Karas
    Commented Nov 11, 2020 at 5:24
  • Wonder if it could fit in a palm router. Commented Nov 11, 2020 at 17:53
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    @PeteKirkham, I would think the router would rotate too fast. You also likely need variable speed to get the cut started reliably and without damaging the teeth, and without pinballing the bit uncontrollably if something went badly. Commented Nov 12, 2020 at 0:30
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A pipe cutter may fit in the hole.

enter image description here
(source: ftaelectronics.com)

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  • This is the most logical answer. I'd think that a shower drain isn't going to be over 2", and a pipe cutter for 2" pipe isn't going to stick out 4" from the center (assuming the pipe is centered in the hole). It'll give a nice clean cut, and you only have to concentrate on the first couple of twists around to ensure it stays level - after that the cutting blade will stay in the groove and remain square to the pipe (or as square as you started).
    – FreeMan
    Commented Nov 11, 2020 at 13:02
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    This is what I would suggest, except they want a plastic/PVC pipe cutter, which has a ratcheting straight blade. The style in your photo is meant for metal (e.g. copper) pipe. They tend to be limited to smaller diameters and wouldn't work that great on the thicker walls of PVC.
    – Bloodgain
    Commented Nov 12, 2020 at 1:25
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    @Bloodgain I have successfully used that type of a cutter on plastic pipe
    – jsotola
    Commented Nov 12, 2020 at 3:02
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An oscillating tool might fit beside the pipe with blade rotated to 90 degrees

Or buy this fancy blade for it

enter image description here

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  • Interesting, I've never seen one of these. Good to know they make 'em.
    – FreeMan
    Commented Nov 11, 2020 at 13:00
  • These are very handy tools. They aren't "perfect" for almost anything, but they get me out of a lot of jams where nothing else will work or only a very specialized tool would be needed. Commented Nov 12, 2020 at 1:13
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Hands down, cable saw

cable saw

This works faster than you think. The only thing you have to be careful with, mark the pipe with sharpie first and watch that you keep your cut square. If you first score the pipe all the way around on the sharpie mark, that might make it easier to keep square.

I would only use this if I had it on hand - I have cut a lot of PVC with nylon string which is always around. It works so well I wouldn't normally make a trip home or to the store to get this tool. But with the limited space you have here, it might be smart to give yourself every possible advantage.

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    might be worth clarifying what kind of string you used. I can see a lot of people getting frustrated with a cotton, twine, etc. string not making any progress after 8 hours.
    – TylerH
    Commented Nov 11, 2020 at 16:59
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    might also be able to make a preliminary cut with a knife to seat the string into
    – dalearn
    Commented Nov 12, 2020 at 18:09
  • @dalearn - I like the idea of scoring the mark first, but I think it might be easier to score the pipe using the cable saw lightly, then go to town with full pressure. Commented Nov 13, 2020 at 14:09
  • You can find diamond tipped hand saws and they work great. If you go too fast, the PVC will melt and refuse, but a second cut is much easier. I suggest drawing a line on the pipe to follow if possible.
    – Evil Elf
    Commented Feb 22, 2023 at 13:13
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Hot knife would cut the PVC like its butter. I've got one that goes on the end of a Butane soldering iron.

Mind out for fumes though! Added bonus, it will round off the end adding reinforcement, which you can file/deburr after if needed.

enter image description here

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Since I have one, I'd go with a mini hacksaw. I'd be more confident cutting a even/straight line with the longer blade...

Husky 6 in. Mini Hacksaw - the blade is 6", unsure how much the handle adds:

enter image description here

or something more this style, also fitted with a 6" blade:

enter image description here

Searching for "mini hacksaw" at your favorite home center's web page, or online store will get you some of these.

The good news is Pythagoras.. at the max diagonal, you get 14".

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    OP says it a 10x10 square. The mini hacksaw would barely fit let alone have enough room for a sawing motion.
    – MonkeyZeus
    Commented Nov 11, 2020 at 14:02
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    The plastic is soft, some elbow grease is required, the strokes would be short...but it would work. Commented Nov 12, 2020 at 5:47
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There are several tools you could use. Here are a few ideas.

  • Rotary tool - commonly called by the generecized name "Dremel" but offered by many brands
  • Hack saw blade - bare blade held by hand, or on a compact frame, possibly with the blade itself cut short.
  • Reciprocating saw or blade - the bare blade could be worked by hand, or if the pipe is steady, you might be able to walk the blade in a circle around the pipe while holding the saw body above the level of the concrete. It's tough to run a recip saw freehand, ie without its foot resting against the work piece, but sometimes it works.
  • Ratcheting pipe cutter - possibly modified with its handles trimmed short so it can fit into the hole. With shortened handles you might have to operate the cutter with large-jaw pliers.
  • Oscillating multi-tool - Like the recip saw this would have to be operated on an angle (not perpendicular to the pipe) but would be easier to control than the recip saw.

You might also consider repairing the pipe. For example, what if you grind out the stop in the middle of a solvent-welded coupler? The coupler could then slide freely onto the pipe stub to cover and seal the gouges. The coupler could be cut shorter if its full length is not needed or gets in the way.

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Another tricky way:

enter image description here

More detailed explanation, watch: this video.

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I have lots of options I would use my Rotozip and try to make a straight cut. I think it is short enough. My next choice would be a sawsall or a reciprocating saw this will create a beveled cut but that won’t bother anything once glued together. I am not sure if a jig saw will fit but I might try that. my last resort a short cross cut hand saw. This would be a knuckle buster in that tight a place.

I would not try my multi tool the side to side action at an angle would make a mess of the pipe unless the cutter at a 90 would make it with a wide bit but the length would mean having to swap the bit from the left to right but it might work. But I could have it done in less than a minute with the sawsall.

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For these ideas, I've seen a person use a 2 inch by 4 inch piece of wood wider than the concrete hole and then fix the drill to it to keep a constant depth.

One would need a 2x4, saw, some large hose clamps, some wood screws and a very slow cut.

Paul Sellers "poor man's router plane" and Izzy Swan's many drill powered tools gave me this insight.

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