Re: Heat-shaping uPVC guttering downpipe

[Tim Lamb]

In message <mrfcj5$h5m$2...@dont-email.me>, Jethro_uk
<jeth...@hotmailbin.com> writes
>The ongoing question of how best to connect the mini-guttering for my
>shed to a downpipe (without it qualifying for bodge of the century)
>continues.
>
>Current thinking is - since I bought one - to press the downpipe into
>service. It needs some angling to be able to fix to the outlet, and run
>along the shed edge.
>
>I have a heat gun ... am I mad to think I might be able to gently heat
>the uPVC and achieve the required shape ?
>
>If it is do-able, are there any gotchas, or tips ?

To bend, the side walls have to compress, stretch or both.

My experience with plastic (mainly electrical conduit) is that neither
really works. What you can do is to heat a narrow strip around 2/3rds of
the pipe and encourage it to kink. Ideally to get 45 deg. you need a
series of small kinks.

Practice on an off cut.

--
Tim Lamb

[Bob Minchin]

Jethro_uk wrote:
> The ongoing question of how best to connect the mini-guttering for my
> shed to a downpipe (without it qualifying for bodge of the century)
> continues.
>
> Current thinking is - since I bought one - to press the downpipe into
> service. It needs some angling to be able to fix to the outlet, and run
> along the shed edge.
>
> I have a heat gun ... am I mad to think I might be able to gently heat
> the uPVC and achieve the required shape ?
>
> If it is do-able, are there any gotchas, or tips ?
>

I'd be tempted to cut at half the angle of the desired bend. rotate the
two parts and glue back together with PVC solvent weld cement.

[dennis@home]

On 24/08/2015 17:13, Tim Lamb wrote:

> My experience with plastic (mainly electrical conduit) is that neither
> really works. What you can do is to heat a narrow strip around 2/3rds of
> the pipe and encourage it to kink. Ideally to get 45 deg. you need a
> series of small kinks.

You can get bending springs for 20mm and 25mm conduit so they don't kink
or collapse.

I doubt if anyone does one for downpipe though.

[Andy Burns]

Jethro_uk wrote:

> how best to connect the mini-guttering for my shed to a downpipe

> Current thinking is - since I bought one - to press the downpipe
> into service. It needs some angling to be able to fix to the outlet

I remember seeing someone on youtube filling pipe with heated sand to
bend it ...

[tabb...@gmail.com]

maybe cold sand, then a bit of hot then cold.


NT

[newshound]

I'd say hot sand was quite a clever idea because it provides a heat
reserve to keep the pipe soft while bending. The other point about the
sand, of course, is that it prevents the pipe from collapsing when bent.
The same technique can be used on copper and lead pipe, but you have to
pack the sand reasonably firmly. I think it should work for a small
angle or large radius bend, but not for making a sharp elbow (because
you will lose wall thickness on the outside and get buckling on the inside).

[Mike Tomlinson]

En el artículo <mrfcj5$h5m$2...@dont-email.me>, Jethro_uk
<jeth...@hotmailbin.com> escribió:

>The ongoing question of how best to connect the mini-guttering for my
>shed to a downpipe (without it qualifying for bodge of the century)
>continues.

Drain the guttering into a hopper and run a downpipe from the hopper?

--
(\_/)
(='.'=) Bunny says: Windows 10? Nein danke!
(")_(")

[Andrew Gabriel]

In article <4-OdnUnomo414UbI...@brightview.co.uk>,

newshound <news...@stevejqr.plus.com> writes:
> I'd say hot sand was quite a clever idea because it provides a heat
> reserve to keep the pipe soft while bending. The other point about the
> sand, of course, is that it prevents the pipe from collapsing when bent.
> The same technique can be used on copper and lead pipe, but you have to
> pack the sand reasonably firmly. I think it should work for a small
> angle or large radius bend, but not for making a sharp elbow (because
> you will lose wall thickness on the outside and get buckling on the inside).

I have used dry sand to bend 28mm copper, for which I didn't have a
pipe bender. It worked surprisingly well. It was in an old book I
have on working with copper. I tapped end-feed end-caps on to keep it
in, thinking I would slide them off afterwards, but with powdered sand
having got under them, there was no way they would come off. Fortunately
I had plenty of spare at both ends and cut them off.

The other way my old copper book describes is to use pressurised molten
lead in the pipe. It's from before the days of health and safety ;-)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]