'Safely' cutting plastic pipe

[AndrewPritchard]

I need to cut some plastic pipe down it's length, but ONLY on one side. I was thinking of using the tablesaw, and was wondering if anyone had some advice. I was thinking of setting up a second fence, parallel to my regular fence to help keep it straight as it goes into the cut.

What do you all think?

Edited April 20, 2018 by AndrewPritchard
Clarification

[Catco]

I would try with a second fence, but my worry would be slight rotation driving one side or the other into the blade and grabbing/melting the plastic...

[AndrewPritchard]

1 minute ago, Catco said:

I would try with a second fence, but my worry would be slight rotation driving one side or the other into the blade and grabbing/melting the plastic...

I was worried about the rotation too.

[Chet]

I am assuming that your thoughts of using a table saw means there is no bandsaw at your disposal.

 

[AndrewPritchard]

Sorry - should have said: I only need to cut ONE side of the pipe down it's length, not both sides. So a bandsaw will not do

EDIT: Original question updated for clarification

[RichardA]

Why not?  If you have some scrap ply, you can make a sled with a fence clamp the pipe in place and let the bandsaw do the work.

[AndrewPritchard]

10 minutes ago, RichardA said:

Why not?  If you have some scrap ply, you can make a sled with a fence clamp the pipe in place and let the bandsaw do the work.

I don't feel confident that the bandsaw will deal with cutting 12" of pipe down it's length. I am concerned it will tip the whole pipe forward.

[wdwerker]

You could make an L shaped jig and use 2 strips of double face tape to hold the pipe still. Then it shouldn't be any problem to rip just one side. Pipe might try to close the kerf. But if you cut a board that would just fit inside and orient it parallel to the table saw that would help hold the kerf open.

[Brendon_t]

1 hour ago, AndrewPritchard said:

I don't feel confident that the bandsaw will deal with cutting 12" of pipe down it's length. I am concerned it will tip the whole pipe forward.

Agreed, that sounds like a very dangerous way to attempt that cut. If the top were to tip in even a little and be grabbed by the blade, it could easily pull you hands into the blade with it.

I would say that immobilizing the pipe on some sort of sled and running it down the ts would be the best option. 

[krtwood]

Couple dabs of hot glue to a board, board against fence.  No need to get fancy.

[Brendon_t]

10 minutes ago, krtwood said:

Couple dabs of hot glue to a board, board against fence.  No need to get fancy.

Until those dabs release mid cut, blade buried in a now unsupported cylinder which can not only kick back but also try to roll, while being cut exposing the uncut area to a whole blade tooth. 

I've tried cutting a 2” PVC pipe like that. It isn't pretty.

[Tpt life]

Hand saw and file or sander. On the TS the best practice is to have extra length where you can screw through the pipe into a square block. This avoids the rotation. I suppose gluing a fixture on it if it is PVC could also give rotation resistance. 

[Keggers]

The last place I'd try to cut this would be on a table saw. I cringe at all that could go wrong there.

Maybe you could score a straight line down the middle of the pipe using an utility knife and then use a hacksaw to finish the cut. Sure would be safe.

[wdwerker]

The way I am reading this is he only needs to cut a single kerf in the pipe, Not cut the pipe in half. 

[Tom King]

I've made that cut on the table saw, with no problem.   We use lengths of ABS pipe, with about a 1/2" wide slot out of one side to slip over the top of exercise pen sides for puppies.  The expens come with two foot long sections that fold up.  Without the stiffeners, the pens get pushed all out of shape.   

I didn't do anything special to make the cuts-just held it steady as it went through.   I did use some feather boards to keep it against the fence.

[chucknbob]

It sounds like you're trying to rip a pipe in half, is that correct? If so, I wouldn't use a second fence, it may cause a kickback. I would use a featherboard. 

[Keggers]

16 minutes ago, wdwerker said:

The way I am reading this is he only needs to cut a single kerf in the pipe, Not cut the pipe in half. 

That's the way I read it too.

[AndrewPritchard]

23 minutes ago, chucknbob said:

It sounds like you're trying to rip a pipe in half, is that correct? If so, I wouldn't use a second fence, it may cause a kickback. I would use a featherboard. 

No, I'm not trying to cut it in half. I'm only trying to put a cut through *one* wall of the pipe, not through both walls

[Tpt life]

4 minutes ago, AndrewPritchard said:

No, I'm not trying to cut it in half. I'm only trying to put a cut through *one* wall of the pipe, not through both walls

The length? 

[Brendon_t]

56 minutes ago, Tom King said:

I've made that cut on the table saw, with no problem.   We use lengths of ABS pipe, with about a 1/2" wide slot out of one side to slip over the top of exercise pen sides for puppies.  The expens come with two foot long sections that fold up.  Without the stiffeners, the pens get pushed all out of shape.   

I didn't do anything special to make the cuts-just held it steady as it went through.   I did use some feather boards to keep it against the fence.

Oh yeah. I've got a few PVC x pen stabilizers for the same problem.

[Tom King]

I used ABS just because it's black, as are the expens.

[Barron]

You could use a jig saw with a short blade. 

[wtnhighlander]

I would set the TS blade as low as possible to make the cut, and use a featherboard just ahead of the blade. The just push the pipe through. I'd be more worried about the pipe coming up off the blade, than rotating. If the length is short, maybe clamp it to a straight line ripping sled, aka a tapering sled set to zero degrees.

[Marmotjr]

On 4/20/2018 at 10:53 PM, wtnhighlander said:

I'd be more worried about the pipe coming up off the blade, than rotating.

You could add a featherboard to the fence, pushing the pipe down, too.  That has a series of it's own issues too, though, but they are workable. 

If you have access to a 3d printer, I have a smaller featherboard that I designed specifically for vertical orientation available for download: https://www.thingiverse.com/thing:1855246

 

[RJH30518]

Why not just take a board on the side of the pipe and clamp it to the PVC pipe. Put the clamp so that it grabs the inside of the PVC pipe and not across the whole pipe. That will hold the pipe so that it won't twist, and then just run it thru against the fence (board and clamps are away from the fence.