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Cutting 3” Schedule 40/80 PVC pipe lengthwise

DanBrub

Aluminum
Joined
Feb 14, 2019
Location
Tennessee
Hope this the the correct forum! I have an application where I need to remove a 1.75” wide section of 10” long pvc pipe. (See pic). I have tried building a fence and running the pipe through a table saw but as the saw cuts a few inches in length the pipe tries to contract and pinches the blade. A successful first pass is possible but then the pipe is rotated the required arc length and the second cut started. Since the pipe diameter is already trying to contract the blade pinching issue is worse!

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DDoug

Diamond
Joined
Oct 18, 2005
Location
NW Pa
What kind of accuracy are you looking for ?
PVC pipe is made for WASTE, not made for anything else.
No stress relieving is done, no warrantees expressed or implied for usage other than above.
 

Booze Daily

Titanium
Joined
Sep 18, 2015
Location
Ohio
A couple strap clamps or plates, one on each end with a piece of allthread thru the middle to clamp both ends would probably keep it from collapsing during the cut.
 

johnmontrose

Aluminum
Joined
Sep 25, 2007
I have an application where I need to remove a 1.75” wide section of 10” long pvc pipe. (See pic). I have tried building a fence and running the pipe through a table saw but as the saw cuts a few inches in length the pipe tries to contract and pinches the blade.

If it is 10" long, use a handsaw and wedges.

Does your table saw have a riving knife (splitter)? If not, fit one and put a wege in the end as soon as it passes the splitter.

Set it up between two 3" high timbers and use a skilsaw. Follow the cut with wedges. Cut a 12" section of pipe and screw it down in the 1" waste portion each end.
 

Comatose

Titanium
Joined
Feb 25, 2005
Location
Akron, OH
I agree, a table saw with a riving knife should have no trouble at all.

But if this is only 10" long, you might have more success standing it on end and running it through a vertical bandsaw. No pinching problem that way.

Or set your table saw blade height to leave a .01 or so thick skin on the inside, and cut it out with a utility knife. No through cut means no chance for pinching.
 

DanBrub

Aluminum
Joined
Feb 14, 2019
Location
Tennessee
If it is 10" long, use a handsaw and wedges.

Does your table saw have a riving knife (splitter)? If not, fit one and put a wege in the end as soon as it passes the splitter.

Set it up between two 3" high timbers and use a skilsaw. Follow the cut with wedges. Cut a 12" section of pipe and screw it down in the 1" waste portion each end.
I think I can remove the guard and leave the splitter portion and machine wedge to attach to the splitter. Might try it…thx
 

DanBrub

Aluminum
Joined
Feb 14, 2019
Location
Tennessee
I meant to say the pipes were 10’ long, not 10” … sorry for the confusion, although the final product will be 7” long as seen in the pic. I have been slitting 10-ft long pipe sections and then miter sawing them into the 7” lengths. Based on inputs I’m wondering if cutting them into 7” lengths first and then removing the 1.75” section would be easier
 
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DanBrub

Aluminum
Joined
Feb 14, 2019
Location
Tennessee
What kind of accuracy are you looking for ?
PVC pipe is made for WASTE, not made for anything else.
No stress relieving is done, no warrantees expressed or implied for usage other than above.
Minimal accuracy needed…only need slot to visually look straight and parallel
 

DDoug

Diamond
Joined
Oct 18, 2005
Location
NW Pa
Minimal accuracy needed…only need slot to visually look straight and parallel
But your using them in a relaxed position ?
Or are you restraining them somehow ?
Cut to 10" long, put in a filler to hold it at 3" dia.,
then cut lengthwise.
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
QT: Op; I’m wondering if cutting them into 7” lengths first and then removing the 1.75” section would be easier.

I would do that, and make A half shell, or full shell filler with a cut-out and (carefully) run The 7" parts on a radial arm saw.
or (better) stick in a filling (just fit) width board. Put on a couple of C clamps so tight on the board and run the 7" part on the table saw against the fence...(easy peasey)
make a 1.78 gauge for faster marking.
Time with a good set-up and a slow feed about 12 seconds per cut so about 36 seconds per part. The slow feed to have less chance of plastic buildup in the saw blade. Stack them in a carry box so they are aligned for the next operation.
 
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DanBrub

Aluminum
Joined
Feb 14, 2019
Location
Tennessee
But your using them in a relaxed position ?
Or are you restraining them somehow ?
Cut to 10" long, put in a filler to hold it at 3" dia.,
then cut lengthwise.
Yes they become hanging fixtures for items that can slide into the slot but not fall through
 

wood2steel

Cast Iron
Joined
May 17, 2013
Location
georgia
Dan,
scratch the table saw; cut pipe in 10" sections; clamp bottom of pipe to mill table take a center cut pass with 3/8 or 1/2" cutter to relieve stress, move Y axis with DRO both directions from 0 to achieve cutout width. Should go pretty fast
 
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DanBrub

Aluminum
Joined
Feb 14, 2019
Location
Tennessee
Dan,
scratch the table saw; cut pipe in 10" sections; clamp bottom of pipe to mill table take a center cut pass with 3/8 or 1/2" cutter to relieve stress, move Y axis with DRO both directions from 0 to achieve cutout width. Should go pretty fast
Thx, I can see where this would work. Only concern is that the idea requires 3 passes and at top speed the table feed motor ain’t that fast and each item requires clamping setup. But it is a solution if I can’t find something faster
 

BT Fabrication

Stainless
Joined
Nov 3, 2019
snap a chalk line and run a circular saw down the outside of it. or have built overhang made from wood and a couple clamps and cut full or parts.
each short section would be easier to cut.
 

wood2steel

Cast Iron
Joined
May 17, 2013
Location
georgia
Your only other option might be to relieve the initial gap with the saw, and make up a wood box to contain the the 7" pcs, cut an appropriate slot in the box top and use your router with base plate collet bushing to follow the slot outline to create your desired width. I run these weird setups all the time in the Woodworking Mill Shop. PM if I can offer an further input!
Good luck
 








 
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