Band saw blades and PVC, more to chew on

[Bruce Seidner]

Ok, I realize that there is always more than one way to do something, and there are no lives or fortunes at stake here, but there seems to be two distinct camps recommending band saw blades for thin wall 6" PVC.

There is the low tooth 4 to 6 tpi, some skipping some not, and then there is the high teeth 20-28 tpi folks.

Mind you, this is coming from companies that sell band saw blades and other cutting blades to both wood and metal industrial end users. Not just my neighbor. (Though, he is a wizard with things electrical.)

I have cut plenty of PVC with a hand held PVC saw and I have cut wood with a wood saw and metal with a hack saw or metal blade specific miter saw. When it works it works, so no lessons there.

I have never thought to experiment and use an expensive wood miter saw blade on a piece of Rebar.

I could use some help understanding the theory that these camps are operating from. I have found no plastic pipe sellers who have experience cutting or fabricating PVC pipe. It is a holiday so maybe the tech people from some of the PVC manufacturers I emailed will get back to me.

Band saw blades are not that expensive and I suppose I could buy one of each and see what works best.

It is funny, when I have talked to the sales people they have wondered if I would be holding the pipe or if it would be secured to a jig. At first I thought there might be a difference in blade choice. I assured them that I had no intention of holding a 6" round pipe and pushing it through a horsepower of spinning blade. There was no special blade for differences in technique, they just wanted to be able to sleep at night knowing that I would be safe.

[Myk Rian]

I tried cutting a piece of 4" PVC on my BS with a 3-4 tpi blade. It caught, ripped the PVC out of my hand, and bent the crap out of the blade.
Next time, I tried a 14 tpi blade. Cut real easy with no problems.
It leaves a mess of PVC chips all over the place, but a vacuum cleaned that up.

[glenn bradley]

The mess is pretty bad. Static causes the little chips to not all get sucked up by the DC but a vac job right after cutting takes care of most of the mess. IMHO, cutting a round object on something that is running teeth down toward the table (and your all too delicate throat insert) is just a bad idea; DAMHIKT. Finer teeth would be more successful with less chance of sacrificing a blade, your throat insert and your shorts. I just draw a line around the pipe and use a jigsaw; less drama.

[Rod Sheridan]

We cut PVC pipe all the time with a bandsaw at work.

However we either cut it in a horizontal metal cutting bandsaw with a 14 TPI metal cutting blade, or we cut it using a hand held bandsaw with an 18 TPI blade. (Pipe held in a vise).

I don't think anyone would reccomend cutting a piece of any type of pipe using methods that don't include a vise to hold the round object.

It's kind of the reverse of using a wood lathe without a tool rest, except for the fact that the accidents happen just as quick.

regards, Rod.

[Anthony Whitesell]

When thinking of tooth count, remember the pipe may be 4" in diameter but it is really only 1/4" thick. So the same rules apply, aim for 3-6 teeth in the work piece. So a 14tpi is going to be suited than 2-3 tpi.

[Van Huskey]

You plan to use a jig... make sure it holds well.

High TPI 12-18 would be my choice but it is just a gut feeling. The dust is going to be horrible and stick to everything.

Refresh my memory, are you building a fitting you can't buy are trying to save money?

[Bruce Seidner]

You plan to use a jig... make sure it holds well.

High TPI 12-18 would be my choice but it is just a gut feeling. The dust is going to be horrible and stick to everything.

Refresh my memory, are you building a fitting you can't buy are trying to save money?
Yes, I thought it would be interesting to make 2x radius elbows out of segments welded together

[John McClanahan]

Don't try to hold the pipe with you hands. When the saw teeth cut thru to the inside, the teeth WILL try to grab the pipe and spin it out of your hands. A low tooth count blade will grab more. Don't ask how I know, but I know better than to ever try it again!

[Van Huskey]

fyi: He is not planning to hold it by hand!

[Mike Cutler]

High tooth count.
I made some hydroponic trays for a coworker. 6" PVC pipe ripped down the center line, in 10' sections. I think I had a 14 tpi blade, maybe 18.
I've put PVC through the table saw also. I cut about 45 degrees out of the radius for the same co worker. I used a Plywood blade for that. I might have even put the blade in backwards. IIRC
As for the mitersaw blade. The aluminum shower extrusions for our shower were cut with a 120 tooth blade on a DeWalt compound miter saw. Unbelievably noisy and a little unnerving, but the cut looked as if it were polished. I wouldn't do rebar.
It is very messy and those PVC chips stick to everything. It's like someone rubbed them on a cat.

[Lee Schierer]

I tried cutting a piece of 4" PVC on my BS with a 3-4 tpi blade. It caught, ripped the PVC out of my hand, and bent the crap out of the blade.
Next time, I tried a 14 tpi blade. Cut real easy with no problems.
It leaves a mess of PVC chips all over the place, but a vacuum cleaned that up.

It will cut with almost any blade, but if you get aggressive with low tpi blades they can catch and grab the piece out of your hand. Do yourself a favor when cutting round objects of any kind. Put them in a V block and clamp them. It is much safer and will generally yield a superior cut in terms of squareness.

[Bruce Seidner]

Ok, so the only down side to using a high tpi blade is maybe I will spend a bit more time out of doors while these electro-statically supercharged bits of plastic adhere to everything in sight. The lower tpi will cut faster but if I adjust feed rate and everything is jig hold down tight I don't hear any problems with +18tpi. One fellow was concerned about pipe resonance and the proclivity of multiple teeth to catch the material and for tear out. But I am thinking that a well supported slow fed piece will do nicely. This is what I want to make a dozen of, because they are bloody expensive, I can plastic weld easily, and I will get exactly what I want.218171

[Lee Schierer]

Remember that other than the starting and finishing cut, you are cutting a relatively thin material. Low TPI blades are going to vibrate the walls more than a higher TPI blade will. Sort of like trying to rip 1/4" ply with a 24 tooth blade. You'll get a rough cut and lots of vibration.