Re: How to bend waste pipe?

message from Ian Stirling on 20 May 2004

I can.
I have recently been playing with waste pipe as conduit.
Obtain a hot-air paintstripper.
Variable heat is really, really, really handy for this, unless you happen
to luck out and get one with exactly the right temperature.
Otherwise distances are critical.
I've made leakless T-junctions and right-angles that cannot be broken
by hand placed next to the junction.

Basic idea is to either heat the pipe, and bend it slightly, or cut
(a hacksaw is good, the frizz gives a good indicator of melting
point getting close) into correct angles, heat both ends and marry up
the ends and let cool.
If you have a slight leak, it can be easily buttered over using a knife
and a shaving to weld a patch on.
With a few minutes practice, it's not too bad.

If you want to make a bend, and don't care overly about appearance,
but are more interested in strength, simply heat a band three-quarters
around the pipe, and crumple it a bit.
If you stretch it instead, then you end up with thinned walls.
Overdoing each bend can be bad.

Obtain a 2m length of waste pipe, or a couple even, and have a go.
It is not particularly nasty when you'r just bending it.
If joining it, you probably want to do it outside.

Look at the surface of the pipe, it goes from matt, to slightly oily
(bendable) to shiny (right temperature for welding.)
Smell is also an important cue.

A hoover can be a handy thing, to set the pipe fast by sucking air
through it.

I have not been able to make nice sharp right angles by any means,
without wrinkling the wall it's hard to get a 90 degree bend in under
400mm or so.

The easier way is just to make either a straight right-angle, or a
couple of 45 degree bends next to each other if you need a tight bend.

Archived message: Re: How to bend waste pipe? (UK DIY House Repairs)