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Making holes in a plastic tube


#1

Dear All,

In a design I need to make holes in a plastic tube. The experiments
so far to make the holes are : using a hot copper rod, a bezel
setting punch…

The problem is that the holes are not neat enough when made with a
hot rod (it also has the fire scale problem). And with the bezel
setting punch the hole is cutting half a circle & not full.

How can i achieve holes in a tube which has a 10mm outer diameter &
8mm inner diameter???

Thanks in advance,
Hema,
wracking my brains…:wink:


#2

Uh, why can’t you drill it? You don’t say what kind of plastic it is.
I have drilled acrylic, and cut that on a bandsaw.

Elaine


#3

How about putting a piece of dowel inside it and then drilling?

regards Tim.


#4
The problem is that the holes are not neat enough when made with a
hot rod (it also has the fire scale problem). And with the bezel
setting punch the hole is cutting half a circle & not full.

Is it possible to use an appropriate size drill bit?


#5

uh…drill bit…in a hand drill…(and perhaps a harder plastic.-Which
type is the tube?)

R.E.Rourke.


#6

Check your local ‘craft’ stores, I bought a punch (to make holes) of
various sizes at Michaels. I’ve used this punch on metal, leather and
am going to assume it will also work on plastic tubing. It makes a
neat hole.


#7

Have tried the drill bit & the tube that i have is a PVC tube. I
need to bend the plastic to make a bangle so i guess it cannot be
too hard either…

Hema


#8

I am in India so the store that you’ve mentioned cannot be accessed.
It would be great if you could please email me a pic of the punch
that you are talking about.

Thanx.


#9

I find that a step drill makes very nice holes in plastic (tube or
sheet). You can also “break” a drill bit by grinding a 90 degree rake
on the cutting edge. How large or small of a hole do you need to
make? What is the tubing inside diameter and outside diameter?

Jeff


#10

One way of keeping the tube in place is to warm it in hot water and
push it on to a wooden dowel that is a tight fit to keep it rigid
enough to drill. Use a slow drill speed to prevent it binding by
heating up with friction and melting. If you have several to do make
a little jig out of a metal tube to cover the outside with a guide
hole drilled through it in the correct position. If your tubing is
very flexible spray it with plumbers freezing spray to make it rigid
first (or dip in liquid nitrogen if you know someone who has some- a
chiropodist perhaps).


#11

Test a piece first. Liquid nitrogen will indeed harden flexible
plastic, but the tubing may be easily shattered while cold,
especially if you’re trying to drill it.

I worked for a research lab where the boss used vinyl tubing to
demonstrate the effects of liquid nitrogen to visitors. A second in
the flask, then rap it against the bench. It would shatter in a
hundred pieces. Being something of a joker, he usually concluded his
talk on the dangers of the stuff by dipping his hand in the Dewar
flask and flinging a handful at them. (Safe enough - it forms an
insulating layer of gas instantly.)

Al Balmer
Sun City, AZ


#12

Hema,

cholr-fluro-methane is available from a pharmacist for muscular
injuries, and "freeze spray "- (not as cold as liquid nitrogen,)
available at computer supply stores, radio shack, & drugstores…(or
available online, USPS/fed ex global to Bharat)…great for many
jewelry making applications…but sounds counter productive to your
dilemma…

India is a major producer of plastic bangles…perhaps check with
www.indiamart.com for a seller under arts and crafts or plastics
manufacture or post an offer to buy…there are many kinds of
plastics, vinyls, and compounds that can be softened in warmed
water,or fill your softer ( rubber, vinyl,polyurethane) tubing with
wax, then drill slowly…shouldn’t be hard at all…think of what you
have on hand and at your disposal…mainly:

steady the tubing/pipe and drill with electric assist or bow
drill/hand drill or take that heated wire you mentioned earlier and
then just sand the tubing smooth after the hot wire plunge…if
that’s all you have…a nail makes a good punch, taper it to the size
point you wish, even on concrete if that’s all that’s available…many
ways to end this thread…


#13

do a search for Michael’s craft stores… once you’re on the site,
type “Maxi Leather Punch” in the search box there… or just type
Leather punch - they show several kinds.? It will give you an idea
of what the punches look like.