I need to bend some 22mm copper pipe into quite a wide radius curve -
is it possible to use conventional pipe benders to do this (the type
with long handles)?

It's just that from looking at them, they appear to have a fixed radius
former - or is there a way of increasing the radius of the curve you
make?

Above all, I need to produce smooth curves - is there a better way of
doing it?

Any advice would be appreciated...

Nigel Lord

"Nige" wrote in message
...

I need to bend some 22mm copper pipe into quite a wide radius curve -
is it possible to use conventional pipe benders to do this (the type
with long handles)?

It's just that from looking at them, they appear to have a fixed radius
former - or is there a way of increasing the radius of the curve you
make?

Above all, I need to produce smooth curves - is there a better way of
doing it?

Any advice would be appreciated...


get a pipe spring,
http://www.screwfix.com/app/sfd/cat/...12076&ts=74183
£ 1.99 then you can have any radius you like
--
Vass

Nige wrote:
I need to bend some 22mm copper pipe into quite a wide radius curve

How wide is quite wide?

"Nige" wrote in message
...

I need to bend some 22mm copper pipe into quite a wide radius curve -
is it possible to use conventional pipe benders to do this (the type
with long handles)?

It's just that from looking at them, they appear to have a fixed radius
former - or is there a way of increasing the radius of the curve you
make?

Above all, I need to produce smooth curves - is there a better way of
doing it?

Any advice would be appreciated...

Cap up one end, fill with fine sand, cap the other end. Bend over suitable
structure to make the curve. This could be you knee or two metal rollers.
First anneal it. Where the curve is to be heat the copper to cherry red
then quench in water. This makes it more pliable. You will need a
substantial blow lamp to anneal it. You could try it cold first, it may
work. When making the bend, do not make sharp pulls, Gentlly move up and
down the bend pulling a small amount at a time.

Nige wrote:

I need to bend some 22mm copper pipe into quite a wide radius curve -
is it possible to use conventional pipe benders to do this (the type
with long handles)?

It's just that from looking at them, they appear to have a fixed radius
former - or is there a way of increasing the radius of the curve you
make?

Above all, I need to produce smooth curves - is there a better way of
doing it?

Any advice would be appreciated...

For very wide radius, you can use your knee, and just pull on the pipe
till it just yields, then move along a bit.
For anything other than very shallow bends (say a meter radius), this
method won't really work.

"Vass" wrote in message
...

"Nige" wrote in message
...

I need to bend some 22mm copper pipe into quite a wide radius curve -
is it possible to use conventional pipe benders to do this (the type
with long handles)?

It's just that from looking at them, they appear to have a fixed radius
former - or is there a way of increasing the radius of the curve you
make?

Above all, I need to produce smooth curves - is there a better way of
doing it?

Any advice would be appreciated...


get a pipe spring,
http://www.screwfix.com/app/sfd/cat/...12076&ts=74183
£ 1.99 then you can have any radius you like

Only as long as the length of the spring.

Doctor Drivel wrote:
"Vass" wrote...
"Nige" wrote...
I need to bend some 22mm copper pipe into quite a wide radius curve -
get a pipe spring,
http://www.screwfix.com/app/sfd/cat/...12076&ts=74183
£ 1.99 then you can have any radius you like

Only as long as the length of the spring.

You could bend a long radius with a shorter spring - you'd
have to keep moving the spring along and bending just that
part of the tube - it might be a bit tedious, though.

"Chris Bacon" wrote in message
...
Doctor Drivel wrote:
"Vass" wrote...
"Nige" wrote...
I need to bend some 22mm copper pipe into quite a wide radius curve -
get a pipe spring,
http://www.screwfix.com/app/sfd/cat/...12076&ts=74183
£ 1.99 then you can have any radius you like

Only as long as the length of the spring.

You could bend a long radius with a shorter spring - you'd
have to keep moving the spring along and bending just that
part of the tube - it might be a bit tedious, though.

With a large radius it is best to use sand..

Doctor Drivel wrote:

"Chris Bacon" wrote
You could bend a long radius with a shorter spring - you'd
have to keep moving the spring along and bending just that
part of the tube - it might be a bit tedious, though.

With a large radius it is best to use sand..

Quite possibly - if the radius is really long you wouldn't
need anything! I wonder what it's for... gardening?

"Chris Bacon" wrote in message
...
Doctor Drivel wrote:

"Chris Bacon" wrote
You could bend a long radius with a shorter spring - you'd
have to keep moving the spring along and bending just that
part of the tube - it might be a bit tedious, though.

With a large radius it is best to use sand..

Quite possibly

Not quite possible it is. This is not open to debate.

On Thu, 12 Jan 2006 13:50:30 +0000, Nige
wrote:


I need to bend some 22mm copper pipe into quite a wide radius curve -
is it possible to use conventional pipe benders to do this (the type
with long handles)?

It's just that from looking at them, they appear to have a fixed radius
former - or is there a way of increasing the radius of the curve you
make?

Above all, I need to produce smooth curves - is there a better way of
doing it?

Any advice would be appreciated...

A 22mm pipe spring from a shed, mine comes from Wickes, a padded knee, and
a modicum of skill, and strength.
--
Dave Fawthrop dave hyphenologist co uk
17,000 free e-books at Project Gutenberg! http://www.gutenberg.net
For Yorkshire Dialect go to www.hyphenologist.co.uk/songs/

In article ews.net,
"Doctor Drivel" writes:

Cap up one end, fill with fine sand, cap the other end. Bend over suitable
structure to make the curve. This could be you knee or two metal rollers.
First anneal it. Where the curve is to be heat the copper to cherry red
then quench in water. This makes it more pliable. You will need a
substantial blow lamp to anneal it. You could try it cold first, it may
work. When making the bend, do not make sharp pulls, Gentlly move up and
down the bend pulling a small amount at a time.

I've done this to bend 28mm copper, for which I don't have
a proper pipe bender. However, your annealing process is for
wrong metal. Copper is annealed at 700-800C (can be done as
low as just over 400C, but you have to hold it at that
temperature for a long time). There is no state change on
cooling copper, so quenching is not required -- you can cool
it over as long a period as you like. The annealing process
for copper is reversed by flexing and vibration, not by slow
cooling. If you quench it just for ease of handling, watch
out for being burned by steam and boiling water spraying out.

For the sand, make sure it's dry or you'll have difficulty
getting it out of the pipe afterwards. Even so, I sucked a
large cotten wool ball through the pipe with a vacuum cleaner
several times to remove as much sand residue as possible (this
was a gas pipe, so I don't want sand getting into the boiler).
A sand bag makes a good bending former. Do not try to bend
near the end of the pipe -- saw any excess off afterwards.

For 22mm pipe rather than 28mm, I would however use a bending
spring for this purpose. You should still anneal the pipe
before bending it though.

--
Andrew Gabriel

Andrew Gabriel wrote:
"Doctor Drivel" writes:
First anneal it. Where the curve is to be heat the copper to cherry red
then quench in water.

your annealing process is for wrong metal. Copper is annealed at 700-800C
(can be done as low as just over 400C, but you have to hold it at that
temperature for a long time). There is no state change on cooling copper,
so quenching is not required -- you can cool it over as long a period as
you like. The annealing process for copper is reversed by flexing and
vibration, not by slow cooling.

I'm not sure about your terminology or where the last sentence
comes in, but heating to red hot and quenching is fine.

No-one remember Peter Parry's instructions regarding
pipe bending: http://tinyurl.com/bq5fq ?

Mungo :-)

"Chris Bacon" wrote in message
...
Andrew Gabriel wrote:
"Doctor Drivel" writes:
First anneal it. Where the curve is to be heat the copper to cherry red
then quench in water.

your annealing process is for wrong metal. Copper is annealed at 700-800C
(can be done as low as just over 400C, but you have to hold it at that
temperature for a long time). There is no state change on cooling copper,
so quenching is not required -- you can cool it over as long a period as
you like. The annealing process for copper is reversed by flexing and
vibration, not by slow cooling.

I'm not sure about your terminology or where the last sentence
comes in, but heating to red hot and quenching is fine.

The fact that it works does not mean that it is the right technique. As
Andrew says, the right method for a soft anneal is to bring the copper to
dull red (600-800C), not cherry red (900-1650C). The method of cooling is
also irrelevant. Quenching may be convenient, but it can also be quite
dangerous if done improperly. Copper will anneal just as well if left to
cool in air.

Colin Bignell

In article ,
Chris Bacon writes:
Andrew Gabriel wrote:
"Doctor Drivel" writes:
First anneal it. Where the curve is to be heat the copper to cherry red
then quench in water.

your annealing process is for wrong metal. Copper is annealed at 700-800C
(can be done as low as just over 400C, but you have to hold it at that
temperature for a long time). There is no state change on cooling copper,
so quenching is not required -- you can cool it over as long a period as
you like. The annealing process for copper is reversed by flexing and
vibration, not by slow cooling.

I'm not sure about your terminology or where the last sentence
comes in, but heating to red hot and quenching is fine.

Didn't say it wasn't, just pointing out it isn't necessary to go
to those lengths. In particular, quenching is used to preserve
crystaline structures which would not normally exist at lower
temperatures, by super-cooling them into a preserved state.
There is no such cystaline state change with copper on cooling,
so it's pointless. With copper, the reverse process to annealing
is work-hardening, which is triggered by flexing and vibration.

For bending a large thick piece of copper, it should be reannealed
during the bending process, or bent at a temperature which is high
enough to keep annealing it throughout the process. This counteracts
the work hardening caused by the bending itself. One way this
used to be done with very large copper pipes was to fill them with
molten lead under pressure instead of sand, at a suitable temperature.

--
Andrew Gabriel

Andrew Gabriel wrote:
For bending a large thick piece of copper, it should be reannealed
during the bending process, or bent at a temperature which is high
enough to keep annealing it throughout the process. This counteracts
the work hardening caused by the bending itself.

Yes, yes...


One way this
used to be done with very large copper pipes was to fill them with
molten lead under pressure instead of sand, at a suitable temperature.

I want you to tell me more about this, please.

nightjar nightjar@ wrote:
"Chris Bacon" wrote in message
Andrew Gabriel wrote
"Doctor Drivel" writes:
First anneal it. Where the curve is to be heat the copper to cherry red
then quench in water.

your annealing process is for wrong metal. Copper is annealed at 700-800C
(can be done as low as just over 400C, but you have to hold it at that
temperature for a long time). There is no state change on cooling copper,
so quenching is not required -- you can cool it over as long a period as
you like. The annealing process for copper is reversed by flexing and
vibration, not by slow cooling.

I'm not sure about your terminology or where the last sentence
comes in, but heating to red hot and quenching is fine.

The fact that it works does not mean that it is the right technique.

And so - it will work, which is what I *said*.

As
Andrew says, the right method for a soft anneal is to bring the copper to
dull red (600-800C), not cherry red (900-1650C). The method of cooling is
also irrelevant. Quenching may be convenient, but it can also be quite
dangerous if done improperly. Copper will anneal just as well if left to
cool in air.

I'm afraid you have imparted no extra knowlege whatever.

In article ,
Nige wrote:
I need to bend some 22mm copper pipe into quite a wide radius curve -
is it possible to use conventional pipe benders to do this (the type
with long handles)?

It's just that from looking at them, they appear to have a fixed radius
former - or is there a way of increasing the radius of the curve you
make?

No - they work at a fixed radius, unless you can buy other formers.

Above all, I need to produce smooth curves - is there a better way of
doing it?

The other common ways to bend pipe is to use a spring, or fill it with
sand, plug the ends then bend it to what you want.

--
*Never put off until tomorrow what you can avoid altogether *

Dave Plowman London SW
To e-mail, change noise into sound.

"Chris Bacon" wrote in message
...
nightjar nightjar@ wrote:
....
The fact that it works does not mean that it is the right technique.

And so - it will work, which is what I *said*.

You obviously take no pride in your work if you do not prefer to use the
right method.

Colin Bignell

On Fri, 13 Jan 2006 00:01:33 -0000, "nightjar" nightjar@insert my surname
here.uk.com wrote:


"Chris Bacon" wrote in message
...
nightjar nightjar@ wrote:
...
The fact that it works does not mean that it is the right technique.

And so - it will work, which is what I *said*.

You obviously take no pride in your work if you do not prefer to use the
right method.

*Right* is a concept which exists only in the minds of *people*.
There are always different ideas of *right* held by different groups of
people.

What OP is saying is follow my opinion of right.
--
Dave Fawthrop dave hyphenologist co uk
17,000 free e-books at Project Gutenberg! http://www.gutenberg.net
For Yorkshire Dialect go to www.hyphenologist.co.uk/songs/

"Dave Fawthrop" wrote in message
news ....
*Right* is a concept which exists only in the minds of *people*.
There are always different ideas of *right* held by different groups of
people...

Copper anneals at dull red heat and melts within the range of cherry red
heat. Presuming that melting the tube is an undesirable result, the right
method is set by physics and is not simply an opinion.

Colin Bignell

On Fri, 13 Jan 2006 08:20:23 -0000, "nightjar" nightjar@insert my surname
here.uk.com wrote:


"Dave Fawthrop" wrote in message
news ...
*Right* is a concept which exists only in the minds of *people*.
There are always different ideas of *right* held by different groups of
people...

Copper anneals at dull red heat and melts within the range of cherry red
heat. Presuming that melting the tube is an undesirable result, the right
method is set by physics and is not simply an opinion.

The ?laws? of science, including physics, are *only* an agreement by
scientists in general that this is the best idea of reality we have at the
moment. Popper IIRC believes that all "Scientific laws" will be
overturned or drastically modified within 200 years of formulation.
http://en.wikipedia.org/wiki/Scientific_law
A physical law, scientific law, or a law of nature is a scientific
generalization based on empirical observations. They are conclusions or
hypotheses which have been confirmed by repeated scientific experiments
over many years, and which have become accepted universally within the
scientific community.
Also http://en.wikipedia.org/wiki/Karl_Popper

A classic example of laws being found wrong is Newton's Laws of Motion,
http://en.wikipedia.org/wiki/Newton's_laws_of_motion which still describe
motion of most bodies in an *Engineering* sense perfectly. However they
fail on an atomic scale when Quantum physics describes atomic and sub
atomic particles better. Also they fail on an astronomical scale where
Einstein's theories of relativity give better results
--
Dave Fawthrop dave hyphenologist co uk
17,000 free e-books at Project Gutenberg! http://www.gutenberg.net
For Yorkshire Dialect go to www.hyphenologist.co.uk/songs/

nightjar wrote:
"Chris Bacon" wrote...
nightjar wrote:
The fact that it works does not mean that it is the right technique.

And so - it will work, which is what I *said*.

You obviously take no pride in your work if you do not prefer to use the
right method.

Are you really a contemptible pillock?

In article ,
Chris Bacon writes:
Andrew Gabriel wrote:
One way this
used to be done with very large copper pipes was to fill them with
molten lead under pressure instead of sand, at a suitable temperature.

I want you to tell me more about this, please.

Not sure I have any more info. I got it from an old book on using
copper (which is also where I learned of filling with sand to
bend pipes). There was a photograph of two young factory workers
bending a pipe this way. Next time I'm over at my parents', I'll
dig out the book and see if it says anymore. It's hardly suitable
for 'd-i-y' pipe bending though;-)

--
Andrew Gabriel

Dave Fawthrop wrote:
On Fri, 13 Jan 2006 08:20:23 -0000, "nightjar" nightjar@insert my surname
here.uk.com wrote:


"Dave Fawthrop" wrote in message
news ...
*Right* is a concept which exists only in the minds of *people*.
There are always different ideas of *right* held by different groups of
people...

Copper anneals at dull red heat and melts within the range of cherry red
heat. Presuming that melting the tube is an undesirable result, the right
method is set by physics and is not simply an opinion.

The ?laws? of science, including physics, are *only* an agreement by
scientists in general that this is the best idea of reality we have at the
moment. Popper IIRC believes that all "Scientific laws" will be
overturned or drastically modified within 200 years of formulation.

Which is utterly irrelevant.
Deeper understanding of the physics of copper does not change the
underlying physics of how it behaves when heated.

The mechanics of forming copper have not changed throughout human
history - and what happens when you bend it and heat it is unlikely to
change in the future.

New physical laws have to fit within existing observations, which means
that it's very, very unlikely anyone will work out a different way to
anneal copper using heat.

Many areas of physics have been explored with exquisitely sensitive
instruments, and all the existing laws work down to those scales.

If you have a new theory, it is only useful if it conforms to all
existing experiments - or it's patently false, or if it differs in some
way from existing theory in some way that's testable.

Many thanks for all the useful replies to my question. The sand & heat
method did the trick...

Nigel Lord


In article , Nige
wrote:

I need to bend some 22mm copper pipe into quite a wide radius curve -
is it possible to use conventional pipe benders to do this (the type
with long handles)?

It's just that from looking at them, they appear to have a fixed radius
former - or is there a way of increasing the radius of the curve you
make?

Above all, I need to produce smooth curves - is there a better way of
doing it?

Any advice would be appreciated...

Nigel Lord