cutting large diameter plastic pipe

[opticsguy]

I often use my mill for more than just cutting wood boards.
Facing me now, is a project that requires the cutting of a 12" diameter plastic pipe with 3/4" thick walls.  Need to cut 3" wide rings and plan to use my mill for this project.

Obviously holding the pipe very solid and cutting slowly will be a requirement. Anyone here ever cutting plastic on a mill before?  Looking for experienced recommendations and cautions please.

Thank you!!

[mad murdock]

Have not cut it in a mill, but have cut plenty with a skill saw.  Schedule 80 10" and 12". We "rip" them lengthwise at work and use it for a sliding gate system in our auger bins for our fertilizer hauling and spreading ops to support our helicopters in the woods. It cuts like butta'.

[tule peak timber]

Tooth space and geometry are not optimum for cutting plastics . Make sure you have adequate toothset, slow steady speed, and coolant to avoid heating. I've cut both PVC and epoxy plastics no problem. Think out your clamping strategy to avoid shape changing the piece as it is being milled. Rob

[Chuck White]

Should cut OK as long as it's secured!

I've cut 4" schedule 40 with a chainsaw, it works better than you'd think, just don't be in a hurry, slow and easy.

[AnthonyW]

Here's a rule of thumb I was taught and have always used. There should be as few teeth as possible in the work piece when cutting, but never less than 3. IIRC, the mill blades I am using have teeth spaced at 3/4". This would violate my rule. The reason for the rule, is to avoid the tooth grabbing at the piece when entering and then having bad things happen. With a 3 tooth minimum, the teeth in the piece act like rakes (the rakes from a chainsaw chain) and prevent the piece from "over feeding" and reducing the likelihood the next tooth will bite off more than it can chew.

This is my way of thinking and how I was taught. Rarely have I come near a situation where I couldn't change the tool or blade and meet this rule. This could be a first.

[drobertson]

Yep, there will be some frillies, if you know what I mean, it will saw out fine.  It saws out great, feed it through, and it will be done.

[Den-Den]

I had a scary incident cutting 6" PVC pipe on a shop band-saw once.  It was secured in a clamp to prevent rotation but a tooth caught an edge, the clamp slipped or something; BOOM - there was sharp pieces of PVC scattered around my shop and I needed a couple of band-aids.  It could have been much worse, I would be very concerned about cross-cutting it on a mill.

[GAB]

I've removed the top off of some 15 gallon plastic barrels using the saw mill.
Clamping is important as well as going slow.
I do not know how the plastic barrels compare to what you are trying to cut.
Note: The shorter the piece being sawed the less leverage the blade will have.
Gerald

[Magicman]

You obviously will have to clamp it and that plastic pipe is slick.  Personally, I pop a chalk line and use a Skil saw.

[thecfarm]

PVC pipe will do some weird stuff when it breaks. I have cut some with a meatl balde with no problems. I would not want to use a balde with teeth,be it a skil saw blade or a bandsaw. But he did say plastic,but not what kind. I would cut a plastic culvent without any doubt,PVC,I have some doubts.

[Larry]

I had a scary incident cutting 6" PVC pipe on a shop band-saw once.  It was secured in a clamp to prevent rotation but a tooth caught an edge, the clamp slipped or something; BOOM - there was sharp pieces of PVC scattered around my shop and I needed a couple of band-aids.  It could have been much worse, I would be very concerned about cross-cutting it on a mill.

I've had the same experience.  I still do it at times but with a lot more caution.

I have cut it on the table saw, circular saw, RAS, chop saw, and probably a few others I have forgot about.  No problem at all.  I've also found those multi tools with oscillating blades work great.  Probably the heaviest I've cut is schedule 40.

Welding shops sell a fiber band to wrap around pipes so you can mark a line for a square cut.  I would definitely use one on 4" and bigger with some methods of cutting.

[Sheepkeeper]

You obviously will have to clamp it below the half way point and that plastic pipe is slick.  Personally, I pop a chalk line and use a Skil saw.

MM I think he's cutting cookies, or in this case donuts  :D

[Magicman]

MM I think he's cutting cookies, or in this case donuts

Yup, thanks. I obviously misread it, and as a matter of fact had caught the mistake before I read your post.  The OP clearly stated 3" rings.  I still would be hesitant without a firm way of clamping it. 

Maybe take two 2X6's and cut a half moon out of each slightly smaller than the outside diameter of the 12" pipe.  Iffy at best.

[backwoods sawyer]

take two 2x4's and build an x that fits snuggly inside and clamp firmly, add half moons on outside if need be. Would not want to take more then 2-3 rings at a time to keep the clamp point near the cut line
May have to block it up into 18"-20" sections then mill 3" out of them.

[beenthere]

I visualize a clamp made out of roller chain that simulates a plumbers pipe clamp (pipe threaders use something similar) and an oil filter clamp that uses roller chain. Going to need something to keep any temptation of that pipe to roll with the blade.

And still, I'd be real skeptical of bandsaw blades used for cutting logs as the teeth are too far apart. I'd look for an alternate tool to do the cutting.

[rooster 58]

I cut a lot of schedule 40 pipe and conduit on my miter saw. It's very accurate and precise, and does a much nicer job than by hand. Just start the cut slow and advance to medium feed rate ;)

[Don_Papenburg]

Sawsall, sabre saw, RAS, hand saw (cross cut),table saw, miter saw,and a pipecutter will all do a fine job

[Wallys World]

Look at ordering a blade with finer teeth. Possibly McMaster Carr, you should be able  to order to the proper length.

[Chuck White]

I think any bandmill blade will do the job as long as the pipe is solidly secured and you don't feed too fast!

[Tree Dan]

Clamping that pipe on the mill is key.
How long of a pcs of pipe are you putting on the mill?
I would think if the pipe is say 16" to 24" that's a lot of leverage
and if it moves back with the blade half way in the cut...what going to happen next

[drobertson]

Well, The first thing would be how long are the pipe sections to begin with,  a 12" pipe is a good size dia.
Figuring on any waste is or could be problematic depending on the available stock.   All said, try a piece using a chain saw, I know this sounds ridiculous, but it would aid in shortening the pieces.  Then cut two sets of v-blocks, one pair 6-3/4" thick the other pair 3-3/4" thick.  Saw down to the 5" on all the pieces then take the shorts and use the 2" ones to finish the rest.  the Pipe will rest on a one inch board spanning the bed rails between the clamping v's the bed rails, an 8" should work.  Depending on the depth of the v notches.  Make a layout and see what you need.  If the chain saw does not work, use a hand saw to rough out the manageable pieces to fit the length needed to fit the height capacity of your mill.   I would say 24" range.  Just a shot in the dark here. Other wise sub the job out to a machine shop with a band saw that has a 12" saw capacity..

[pineywoods]

I assume we are talking some variety of PVC pipe. When I was told of this method of cutting plastic pipe, I asked the guy what kind of happy weed he was smoking. I didn't believe him and had to be shown. Now before you assume ole pineywoods has done flipped his lid, try this. A three foot  piece of ordinary nylon twine with a handhold loop on each end. Wrap the twine halfway around the pipe and grab the end loops one in each hand. Pull the twine tight and se-saw it back and forth around the pipe, while keeping tension on the twine. Cuts faster than a hack saw and leaves a smooth finish on the cut. CRAZY, yep, but it works...

[drobertson]

I believe you!  and got to try this for sure,!  I know you're not crazy,  just how much is to be cut?

[Contractor1]

A 12" pipe with a 3/4" wall may be hdpe. If it is hdpe it will want to shred and build up on your wheels. If you are just cutting ring it may not. I tried to split some 30" hdpe on my hd 40, it cut fine but the build up made it not worth it. HDPE ill b solid black or have stripes on each side.

[Solomon]

I have NOT cut any plastic pipe on my mill at all.  However, my thought on the matter is that if you're going to be cutting "rings" ,   Laguna makes a high quality carbide band blade they call the " Resaw King "  it's pretty pricey,  around $2.00 per inch.  The teeth look like the teeth on an 80 tooth 12 inch miter saw blade.     Now, obviously you will have to clamp short sections of pipe standing verticly on the deck.  If you could find a square slab of pvc matieral a couple inches thick and say.......  16 x 16 inches , then glue the end of the pipe to it (giving the glue plenty of time to set)  this would give you the means to clamp it securely.  When you get to  the bottom, you can skim the top of the slab off cleanly and flat in order to glue the next section of pipe to it.   I have never tried this, it's just some abstract thought of mine , so I invite brutaly honest critisisim from the expierenced sawyers out there.    Does anyone see any issues with this idea ? 
Does anyone see any safety concerns ?   Feedback Please  !!!

[AnthonyW]

Along the lines of what Solomon said, there is no particular reason to use a bandmill saw blade to cut the rings with the wide spaced teeth (3/4 and 7/8" pitches). Thinking slightly outside the box, as this job already is. If you can fit a 1" blade on the mill wheels, there are 10tpi and 6tpi blades available that can be cut to length for you. just be careful when you tension it, the usual rules won't apply.

[Nomad]

     You can't mount a 1" band on a mill with guide wheels designed for 1¼" band; won't work.

[opticsguy]

OP here,  thanks for all the input. I wont be cutting these rings for a month, just something I am preparing for.  For clarification, the 12" diameter pipe would be stood on end and very securely fastened.  I only need two rings, 12" diameter and 3" wide.  A slow feed will probably do the trick however it was interesting about the possible build up of the plastic on wheels, guides etc.

One more thought, someone on another thread mentioned they removed the blade guides on their saw and seemed to be no difference in the cutting.  So using a 1" or smaller blade on the mill without guides might?? be possible?

Or??

Thanks again!!

[tule peak timber]

I have NOT cut any plastic pipe on my mill at all.  However, my thought on the matter is that if you're going to be cutting "rings" ,   Laguna makes a high quality carbide band blade they call the " Resaw King "  it's pretty pricey,  around $2.00 per inch.  The teeth look like the teeth on an 80 tooth 12 inch miter saw blade.     Now, obviously you will have to clamp short sections of pipe standing verticly on the deck.  If you could find a square slab of pvc matieral a couple inches thick and say.......  16 x 16 inches , then glue the end of the pipe to it (giving the glue plenty of time to set)  this would give you the means to clamp it securely.  When you get to  the bottom, you can skim the top of the slab off cleanly and flat in order to glue the next section of pipe to it.   I have never tried this, it's just some abstract thought of mine , so I invite brutaly honest critisisim from the expierenced sawyers out there.    Does anyone see any issues with this idea ? 
Does anyone see any safety concerns ?   Feedback Please  !!!

Respectfully,,,ZERO success with the Laguna blades on my sawmill or in the shop. Lots of wasted $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

[SPIKER]

I would cut a hunk big enough to make mounts out of, split 24" in half length wise.   take each half and screw it into some dim lumber.   Then use those half lengths of pipe to clamp the vertical section. 

I  would think that finer toothed blade with medium lower blade speed and shoving the thing thru faster will cut cleaner.   Just have to make sure the work dont move  ;)

Mark

[blade69001]

I would use a skillsaw and a couple pairs of vise grips for this project. Using a mill seams like a bunch of extra work. Strap the tube on some benches so it won't move. Snap the vise grips to the deck of the skillsaw making a three inch stop. Perfect 3" rings every time.

[LittleJohn]

Table saw and a fence  ;D

Used this method to cut the tops off a couple of old 5-gal buckets, that the bottums blew out off.  Used the "forms" to make concrete pavers with the munchkins hand prints in

[Solomon]

I have NOT cut any plastic pipe on my mill at all.  However, my thought on the matter is that if you're going to be cutting "rings" ,   Laguna makes a high quality carbide band blade they call the " Resaw King "  it's pretty pricey,  around $2.00 per inch.  The teeth look like the teeth on an 80 tooth 12 inch miter saw blade.     Now, obviously you will have to clamp short sections of pipe standing verticly on the deck.  If you could find a square slab of pvc matieral a couple inches thick and say.......  16 x 16 inches , then glue the end of the pipe to it (giving the glue plenty of time to set)  this would give you the means to clamp it securely.  When you get to  the bottom, you can skim the top of the slab off cleanly and flat in order to glue the next section of pipe to it.   I have never tried this, it's just some abstract thought of mine , so I invite brutaly honest critisisim from the expierenced sawyers out there.    Does anyone see any issues with this idea ? 
Does anyone see any safety concerns ?   Feedback Please  !!!

Respectfully,,,ZERO success with the Laguna blades on my sawmill or in the shop. Lots of wasted $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

I don't think I will be buying a resaw king blade for my mill in light of your post.  My mill blades are 229 inches  1 1/2.   That would be over $450.00 wasted on one blade.   Thanks for the info Brother !

[petefrom bearswamp]

Never tried 12" plastic but cut plenty of smaller stuff on my miter and table saw, up to 6"
Did cut off 15" dia aluminum culvert pipes in my guided youth with my old but reliable Homelite XL12.
Lots of debris but came out Ok.
My table saw works very well on 6" stuff being careful, 12" I am not sure.