Thread: Holey PVC

I've drilled very neat 38 mm diam holes into PVC pipe with one of those conical step drills where the last step was 38mm.

If you know someone with a a MW lathe it might be possible to make a larger one out of mild steel?

Another possibility would be a dremel router. I use one of these on flat PVC, Acrylic etc and it cuts very neat holes.
With these things the edges are only as neat as the template

Hi,
I have cut 60mm holes in 100mm pipe with no trouble, but I think your holes are getting so close to the size of the pipe that the teeth are approaching the wall at 90 deg and you are getting the same effect as when cutting a metal pipe with a hacksaw, if you do not turn the pipe when approaching half way. As you can not turn the hole saw to the pipe I would try putting a piece of wood in the pipe so that when the saw is at too high an angle it starts cutting the wood as well and slows the feed so that it takes small shavings off the PVC without biting in.
Have not tried it but it should work.
Regards

Originally Posted by popawisky

Hi Good people
Trying to cut a number of 80mm holes in 90mm PVC storm pipe, to put
small plant pots in.
Tried different hole saws but they jam and split the PVC.
A router will do the job but not a neat finish.
Any tips on the best way to do this???????
Pete

Seeing that the size of the hole that you're trying to make is almost the same as the diameter of the pipe, you might find it easier to cut the hole using a saw. I did something similar for a mate who is in to hydroponics. He wanted some 80 mm cut-outs made in the side of 1 meter lengths of 100mm PVC DWV pipe, so the job was not much different to what you're trying to do.

What we ended up doing was to make a template out of cardboard. We used that template to mark the outline of each cut-out using a permanent marker. I then cut along the marked lines using the 18 inch bandsaw. You need to plan your cut sequence and cut directions so that the length of pipe doesn't end up hitting the bandsaw frame half way through a cut, but once you've got your head around that, it is a quick and easy job. I used a 10 mm wide 14 TPI blade, and got a pretty clean cut.

SAFETY WARNING

Safety wise, most "how-to use a bandsaw" books tell you that if you're going to cut through a cylinder (i.e. a PVC pipe) on a bandsaw, then for safety sake, you should secure the pipe in a suitable sized V-Block. The danger is that when approaching the blade at the beginning of the cut, and when cutting out of the pipe at the end of the cut, the blade will be cutting about 50mm above the bandsaw table. The downward force of the blade on the outer edge of the pipe in these parts of the cuts could theoretically cause the pipe to spin (if the blade catches), potentially causing the blade to jam and break, or potentially causing some injury to the operator.

In making the cutouts in the 100mm PVC pipe, I couldn't think of a way to mount the pipe in a V-Block that would suit this curved cut. So I mitigated the risk as much as I could by using the finest tooth blade that I had on hand (a 14 TPI), and a gentle touch. I made about 20 cuts like this, without using a V-Block, and I didn't run into any problems with catching, broken blades, etc - and I've still got all my fingers.

An alternative to using a bandsaw, if you've only got a few cut-outs to do, could be to use one of those oscillating multi-tool saws, but I don't think it would be very easy to do a reasonably neat curved cut with one of those things.

One other possibility that I hadn't considered until now, would be to use a Jig Saw. Mark the cut-out using the template and a permanent marker. Drill a starter hole, and go at it with the jig saw. Have someone hold and carefully turn the pipe as you cut, which would allow you to keep the blade cutting perpendicular to the surface of the pipe. It would be a fiddly job, but I can't see why it wouldn't work.....

Hope that helps,

RoyG

Yep Hydroponics is what I am doing.
Have succeeded by using a 76mm Sutton hole saw, and running the drill in reverse.
Sounds crazy but I have the most beautiful hole you ever saw.
Pete

Originally Posted by popawisky

Yep Hydroponics is what I am doing.
Have succeeded by using a 76mm Sutton hole saw, and running the drill in reverse.
Sounds crazy but I have the most beautiful hole you ever saw.
Pete

Agree with this totally, I have a set of cheap crappy hole cutters but running in reverse does wonders, just be aware with the cheap sets that the securing nut stays firm... mine likes to loosen itself.

if you think hydroponics is fun (and the inuendo relationship its invollved with) have a look at
http://www.backyardaquaponics.com/forum

instead of paying on on stuff to grow your plants spend it on fish food, feed them and they fertilise your plants.