I need to re-route some mains cables which squeeze through a hole
alongside hot water pipes. I'm planning to remake the joints with
insulated crimps and heat shrink sleeving.

I'll avoid the cheap 3 quid crimp tools and get a ratchet one, is there
much to be gained by getting the £25 one from Screwfix as opposed to the
£10.50 one from Toolstation?

Judging from the flexibility of the cables I think they are old 7/029
and 7/036. Will crimps grip OK on this or are they only suitable for
modern metric stuff?

I intend to cut the individual conductors to different lengths to avoid
bulky joints with all 3 crimps side by side. Am I right in assuming that
I don't need to put sleeving over the individual (insulated) crimps but
just over the complete cable to replace the PVC sheath? I was planning
to use wide black heat shrink from Maplin for this, is it tough enough
for the job?

This is my first time using heat shrink on mains cable. Previous jobs
have been on small electronic bits where I just wiped the back of the
soldering iron along the sleeving to shrink it. This isn't going to work
for the big stuff, will a hot air gun be OK - knowing what it does to
paint I'm a bit nervous about using it on PVC cable but SWMBO's
hairdryer doesn't seem hot enough.

--
Mike Clarke

In message , Mike Clarke
writes
I need to re-route some mains cables which squeeze through a hole
alongside hot water pipes. I'm planning to remake the joints with
insulated crimps and heat shrink sleeving.


Judging from the flexibility of the cables I think they are old 7/029
and 7/036. Will crimps grip OK on this or are they only suitable for
modern metric stuff?

I should imagine so.

I intend to cut the individual conductors to different lengths to avoid
bulky joints with all 3 crimps side by side. Am I right in assuming
that I don't need to put sleeving over the individual (insulated)
crimps but just over the complete cable to replace the PVC sheath?

That's what I did.

I was planning to use wide black heat shrink from Maplin for this, is
it tough enough for the job?

I had some of that so used it, seems fine.

This is my first time using heat shrink on mains cable. Previous jobs
have been on small electronic bits where I just wiped the back of the
soldering iron along the sleeving to shrink it. This isn't going to
work for the big stuff, will a hot air gun be OK

Yes, you don't need to sit there for long, or hold it too close to
shrink it, the PVC insulation will be fine.


--
Chris French, Leeds

On 28 Sep 2004 Mike Clarke wrote:

I need to re-route some mains cables which squeeze through a hole
alongside hot water pipes. I'm planning to remake the joints with
insulated crimps and heat shrink sleeving.

I'll avoid the cheap 3 quid crimp tools and get a ratchet one, is there
much to be gained by getting the £25 one from Screwfix as opposed to the
£10.50 one from Toolstation?

It's certainly worth getting a proper ratchet crimp tool. I think
Maplin have theirs on offer at the moment. It's a lot less than £25
though that's what I paid for mine a few years ago. I haven't seen the
Screwfix or Toolstation tools.

Judging from the flexibility of the cables I think they are old 7/029
and 7/036. Will crimps grip OK on this or are they only suitable for
modern metric stuff?

Most mains cable is now solid core. If you've got old rubber covered
flexible stuff consider whether you should be replacing the whole lot.
Either way, isn't it a lot easier just to use a junction box? You don't
really want to be making the joints where the cable squeezes past the
pipe. In any case that should be avoided as the heat will make the
insulation brittle.

I intend to cut the individual conductors to different lengths to avoid
bulky joints with all 3 crimps side by side. Am I right in assuming that
I don't need to put sleeving over the individual (insulated) crimps but
just over the complete cable to replace the PVC sheath? I was planning
to use wide black heat shrink from Maplin for this, is it tough enough
for the job?

I would tape the joints and then tape the whole lot together if I was
going to do it that way, but as I said I'd rather use junction boxes.

This is my first time using heat shrink on mains cable. Previous jobs
have been on small electronic bits where I just wiped the back of the
soldering iron along the sleeving to shrink it. This isn't going to work
for the big stuff, will a hot air gun be OK - knowing what it does to
paint I'm a bit nervous about using it on PVC cable but SWMBO's
hairdryer doesn't seem hot enough.

A hot air gun is fine, or a blowlamp if you're careful and don't get
the flame too close. Use a plumber's soldering mat to protect
surrounding paintwork. You won't need to apply heat for long enough to
do any damage.

--
Richard Porter
Mail to username ricp at domain minijem.plus.com
"You can't have Windows without pains."

"Richard Porter" wrote in message
...
On 28 Sep 2004 Mike Clarke wrote:

snip

Judging from the flexibility of the cables I think they are old 7/029
and 7/036. Will crimps grip OK on this or are they only suitable for
modern metric stuff?

Most mains cable is now solid core. If you've got old rubber covered
flexible stuff consider whether you should be replacing the whole lot.
Either way, isn't it a lot easier just to use a junction box? You don't
really want to be making the joints where the cable squeezes past the
pipe. In any case that should be avoided as the heat will make the
insulation brittle.

7/029 and 7/036 multi-strand cable is not limited to old rubber covered /
insulated stuff, there must still be some considerable quantity of PVC stuff
around.

In article ,
Mike Clarke wrote:
This is my first time using heat shrink on mains cable. Previous jobs
have been on small electronic bits where I just wiped the back of the
soldering iron along the sleeving to shrink it. This isn't going to work
for the big stuff, will a hot air gun be OK - knowing what it does to
paint I'm a bit nervous about using it on PVC cable but SWMBO's
hairdryer doesn't seem hot enough.

A hot air gun for paint stripping will work fine. If you haven't got one,
a two heat model will be best, and use the low one. You've still got to be
slightly careful, but the shrinking happens long before the PVC melts.

--
*Many people quit looking for work when they find a job *

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

In article , Richard Porter
wrote:

Most mains cable is now solid core. If you've got old rubber covered
flexible stuff consider whether you should be replacing the whole lot.

This is PVC cable, it was introduced a few years before cables went
metric.

Either way, isn't it a lot easier just to use a junction box?

That's what I would have done in the past but I now get the impression
that crimps provide a better permanent joint than screw terminals, and
these joints won't be very accessible afterwards.

You don't really want to be making the joints where the cable squeezes
past the pipe. In any case that should be avoided as the heat will make
the insulation brittle.

Yes, that's why I intend cutting the cables, re-routing them to avoid
the pipes and then linking them up again.

--
Mike Clarke

Mike Clarke wrote:

I need to re-route some mains cables which squeeze through a hole
alongside hot water pipes. I'm planning to remake the joints with
insulated crimps and heat shrink sleeving.

I'll avoid the cheap 3 quid crimp tools and get a ratchet one, is there
much to be gained by getting the £25 one from Screwfix as opposed to the
£10.50 one from Toolstation?

Judging from the flexibility of the cables I think they are old 7/029
and 7/036. Will crimps grip OK on this or are they only suitable for
modern metric stuff?

I intend to cut the individual conductors to different lengths to avoid
bulky joints with all 3 crimps side by side. Am I right in assuming that
I don't need to put sleeving over the individual (insulated) crimps but
just over the complete cable to replace the PVC sheath? I was planning
to use wide black heat shrink from Maplin for this, is it tough enough
for the job?

This is my first time using heat shrink on mains cable. Previous jobs
have been on small electronic bits where I just wiped the back of the
soldering iron along the sleeving to shrink it. This isn't going to work
for the big stuff, will a hot air gun be OK - knowing what it does to
paint I'm a bit nervous about using it on PVC cable but SWMBO's
hairdryer doesn't seem hot enough.



You know, why not solder it and heat shrink?

Crimps are ok for the sort of half trained gibbon that calls itself an
electrician, but really...

In message , Mike Clarke
writes
In article , Richard Porter
wrote:

metric.

Either way, isn't it a lot easier just to use a junction box?

That's what I would have done in the past but I now get the impression
that crimps provide a better permanent joint than screw terminals, and
these joints won't be very accessible afterwards.


Isn't it a regs requirement now anyway that screwed joints be
accessible?

Crimping is quicker as well than fiddling with junction boxes as well.
--
Chris French, Leeds

On Tue, 28 Sep 2004 18:25:10 +0100, The Natural Philosopher
wrote:

Mike Clarke wrote:

I need to re-route some mains cables which squeeze through a hole
alongside hot water pipes. I'm planning to remake the joints with
insulated crimps and heat shrink sleeving.

I'll avoid the cheap 3 quid crimp tools and get a ratchet one, is there
much to be gained by getting the £25 one from Screwfix as opposed to the
£10.50 one from Toolstation?

Judging from the flexibility of the cables I think they are old 7/029
and 7/036. Will crimps grip OK on this or are they only suitable for
modern metric stuff?

I intend to cut the individual conductors to different lengths to avoid
bulky joints with all 3 crimps side by side. Am I right in assuming that
I don't need to put sleeving over the individual (insulated) crimps but
just over the complete cable to replace the PVC sheath? I was planning
to use wide black heat shrink from Maplin for this, is it tough enough
for the job?

This is my first time using heat shrink on mains cable. Previous jobs
have been on small electronic bits where I just wiped the back of the
soldering iron along the sleeving to shrink it. This isn't going to work
for the big stuff, will a hot air gun be OK - knowing what it does to
paint I'm a bit nervous about using it on PVC cable but SWMBO's
hairdryer doesn't seem hot enough.



You know, why not solder it and heat shrink?

Solder should not to be used as the mechanical support alone. If
soldering the wires should be mechanical joined first, e.g. by several
tight twists. The heat shrink is not adequate for mechanical integrity,
only for insulation.

Crimps are ok for the sort of half trained gibbon that calls itself an
electrician, but really...

Crimps are one of the few methods approved for use in hi-reliability
aerospace work. However, that only applies if a proper force-calibrated
ratchet tool is used - and that excludes the el-cheapo £3.95 scissors
rubbish. If you haven't done crimping before I should do a few trials
first and make sure you cannot pull the finished joint apart with a
straight pull.

Phil
The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/
Remove NOSPAM from address to email me

On 28 Sep 2004 chris French wrote:

Crimping is quicker as well than fiddling with junction boxes as well.

I've used crimp terminals quite a lot on cars. Yes they're quick but in
my experience not as reliable as soldered terminals. Using the correct
size terminals or butt connectors for the cable is crucial.

For joining multistrand cables I prefer to mesh the strands, solder and
heatshrink. The heatshrink tube may have to be threaded onto the cable
first! Of course you have to be able to make a good solder joing using
a sufficiently powered iron for the gauge of cable otherwise you melt
the insulation before the solder).

--
Richard Porter
Mail to username ricp at domain minijem.plus.com
"You can't have Windows without pains."

On Tue, 28 Sep 2004 18:06:10 +0100, Mike Clarke
wrote:

In article , Richard Porter
wrote:

Most mains cable is now solid core. If you've got old rubber covered
flexible stuff consider whether you should be replacing the whole lot.

This is PVC cable, it was introduced a few years before cables went
metric.

Either way, isn't it a lot easier just to use a junction box?

That's what I would have done in the past but I now get the impression
that crimps provide a better permanent joint than screw terminals, and
these joints won't be very accessible afterwards.

You don't really want to be making the joints where the cable squeezes
past the pipe. In any case that should be avoided as the heat will make
the insulation brittle.

Yes, that's why I intend cutting the cables, re-routing them to avoid
the pipes and then linking them up again.

I would only cut existing cable as a last resort. Can't you open up the
hole a bit to get some clearance between cable and pipe? Or jam some
cut-down plastic trunking in there to give protection from chaffing?

Phil
The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/
Remove NOSPAM from address to email me

In message , "Dave Plowman (News)"
writes
In article ,
Mike Clarke wrote:
This is my first time using heat shrink on mains cable. Previous jobs
have been on small electronic bits where I just wiped the back of the
soldering iron along the sleeving to shrink it. This isn't going to work
for the big stuff, will a hot air gun be OK - knowing what it does to
paint I'm a bit nervous about using it on PVC cable but SWMBO's
hairdryer doesn't seem hot enough.

A hot air gun for paint stripping will work fine. If you haven't got one,
a two heat model will be best, and use the low one. You've still got to be
slightly careful, but the shrinking happens long before the PVC melts.

NOT CPC again, 'fraid so ...

They sell a nice little catalytic heat gun with a shield which curves
around the back of the wire. It runs on a cigarette lighter and costs
around a tenner. It's not overly powerful, which can be an asset when
using heatshrink.

--
geoff

Phil Addison wrote:
On Tue, 28 Sep 2004 18:25:10 +0100, The Natural Philosopher
wrote:


You know, why not solder it and heat shrink?


Solder should not to be used as the mechanical support alone. If
soldering the wires should be mechanical joined first, e.g. by several
tight twists. The heat shrink is not adequate for mechanical integrity,
only for insulation.

No arguments there. Actually on solid copper I tend to for a U in each
one to be soldered, and twist em up tight to completely lock together,
then flow solder in to completely lock.


Crimps are ok for the sort of half trained gibbon that calls itself an
electrician, but really...


Crimps are one of the few methods approved for use in hi-reliability
aerospace work. However, that only applies if a proper force-calibrated
ratchet tool is used - and that excludes the el-cheapo £3.95 scissors
rubbish. If you haven't done crimping before I should do a few trials
first and make sure you cannot pull the finished joint apart with a
straight pull.

Crimps CAN be very good, and have one huge advantage over soldering -
they do not stiffen stranded wire as solder runs up inside the
insulation. This makes them very very good for areas of vibration, where
solder joints would need to be (expensively) supported.

However the average house suffers little from vibration, and uses solid
core wire anyway.

And, a crimp is totally dependent on how well its made. Its a bit harder
to make a complete mess of solder as long as the iron is hot...


Phil
The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/
Remove NOSPAM from address to email me

On Tue, 28 Sep 2004 14:08:15 +0100, Mike Clarke
wrote:

This is my first time using heat shrink on mains cable. Previous jobs
have been on small electronic bits where I just wiped the back of the
soldering iron along the sleeving to shrink it. This isn't going to work
for the big stuff, will a hot air gun be OK - knowing what it does to
paint I'm a bit nervous about using it on PVC cable but SWMBO's
hairdryer doesn't seem hot enough.

Hi,

If you partly cover the intake on a hairdryer it should be hot enough
to do the heatshrink - or possibly even catch fire!

cheers,
Pete.

On Tue, 28 Sep 2004 18:25:10 +0100, The Natural Philosopher
wrote:


Crimps are ok for the sort of half trained gibbon that calls itself an
electrician, but really...

Would that be why soldering is banned for Milspec, Naval and
aerospace but crimps approved?

In terms of reliability it really is no contest - and solder isn't
the winner - no matter how highly trained the gibbon.


--
Peter Parry.
http://www.wpp.ltd.uk/

In article ,
Richard Porter wrote:
I've used crimp terminals quite a lot on cars. Yes they're quick but in
my experience not as reliable as soldered terminals. Using the correct
size terminals or butt connectors for the cable is crucial.

Since I bought the correct crimp tool - mega bucks - I'd not agree. The
problem with soldered terminals in a car is that they are likely to
fracture - they're not really designed for soldering, and the cable clamp
is too close to the soldered part.

--
*Growing old is inevitable, growing up is optional

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

In article ,
The Natural Philosopher wrote:
And, a crimp is totally dependent on how well its made.

Using the normal crimps and the correct tool it's a bit difficult to get
it wrong...

Its a bit harder
to make a complete mess of solder as long as the iron is hot...

Then just about every factory manages it - given the number of solder
faults you get on older electronic equipment. Including those not subject
to excessive heat and vibration.

--
*I brake for no apparent reason.

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

In message , The Natural
Philosopher writes
Phil Addison wrote:
On Tue, 28 Sep 2004 18:25:10 +0100, The Natural Philosopher
wrote:


Crimps are ok for the sort of half trained gibbon that calls itself
an electrician, but really...
Crimps are one of the few methods approved for use in
hi-reliability
aerospace work.

Crimps CAN be very good, and have one huge advantage over soldering -
they do not stiffen stranded wire as solder runs up inside the
insulation. This makes them very very good for areas of vibration,
where solder joints would need to be (expensively) supported.

However the average house suffers little from vibration, and uses solid
core wire anyway.

And, a crimp is totally dependent on how well its made.

And so is a solder joint.

Its a bit harder to make a complete mess of solder as long as the iron
is hot...

You've not seen my soldering. It's pretty hard to make a mess of a crimp
joint as long as you use the right tool, right crimp etc. I'ts much
easier for me to make a dodgy soldered joint.
--
Chris French, Leeds

Dave Plowman (News) wrote:

In article ,
The Natural Philosopher wrote:

And, a crimp is totally dependent on how well its made.


Using the normal crimps and the correct tool it's a bit difficult to get
it wrong...


Its a bit harder
to make a complete mess of solder as long as the iron is hot...


Then just about every factory manages it - given the number of solder
faults you get on older electronic equipment. Including those not subject
to excessive heat and vibration.

Thermal cycling. I forgot thermal cycling. Nasty on solder joints
especially if they are under tensin from a crop-and-bend machine.

If crimps are so darned good, why don;t we have crimpable chips
resitsiors, capaitors abnd circuit borads?

A good crimp is good on electrcal conductvity, on vibration resistance
and on thermal cycling.

But it can fail like anything else. on stranded wire its potentally more
subject to corrosion as well, as moisture can get trapped in the strands..

Wiring looms in aircaftt are not subject to the same set of conditions
as mains wires in walls, and are totally dissimilar from mass produced
crcuit boards in consumer equipment.

And trained aircfart technicians using proper equipment and subject to
rigourous testing are not the same as half trained gibbons squeezing
crimps with pliers and shoving them in a wall to be plstered over.

chris French wrote:

In message , The Natural
Philosopher writes

Phil Addison wrote:

On Tue, 28 Sep 2004 18:25:10 +0100, The Natural Philosopher
wrote:



Crimps are ok for the sort of half trained gibbon that calls itself
an electrician, but really...

Crimps are one of the few methods approved for use in hi-reliability
aerospace work.


Crimps CAN be very good, and have one huge advantage over soldering -
they do not stiffen stranded wire as solder runs up inside the
insulation. This makes them very very good for areas of vibration,
where solder joints would need to be (expensively) supported.

However the average house suffers little from vibration, and uses
solid core wire anyway.

And, a crimp is totally dependent on how well its made.


And so is a solder joint.

Its a bit harder to make a complete mess of solder as long as the iron
is hot...


You've not seen my soldering. It's pretty hard to make a mess of a crimp
joint as long as you use the right tool, right crimp etc. I'ts much
easier for me to make a dodgy soldered joint.

*shrug*. I do both. Crimps are bulkier and you have to have exactly the
right crimp,and the right tool. Other wise they fall to pieces.

In article ,
The Natural Philosopher wrote:
If crimps are so darned good, why don;t we have crimpable chips
resitsiors, capaitors abnd circuit borads?

Cost of production. You can flow solder over an entire PCB in one go. And
do many PCBs at the same time.
Each crimp would have to be made individually, or with a machine which
did several at once - and it doesn't take imagination to guess what that
would cost.

Also, solder is reliable enough in this context for the design life - say
about 5 years.

FWIW, the harnesses going to those PCBs will invariably have crimped
plugs.

--
*Learn from your parents' mistakes - use birth control

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

In article ,
The Natural Philosopher wrote:
And trained aircfart technicians using proper equipment and subject to
rigourous testing are not the same as half trained gibbons squeezing
crimps with pliers and shoving them in a wall to be plstered over.

But everyone has already said often enough to use the correct tool.
Because of economy of scale, they are much cheaper than other more
specialised crimping tools. Somewhere between 10 and 20 quid buys a good
one.

--
*If at first you don't succeed, avoid skydiving.*

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

Dave Plowman (News) wrote:

In article ,
The Natural Philosopher wrote:

If crimps are so darned good, why don;t we have crimpable chips
resitsiors, capaitors abnd circuit borads?


Cost of production. You can flow solder over an entire PCB in one go. And
do many PCBs at the same time.
Each crimp would have to be made individually, or with a machine which
did several at once - and it doesn't take imagination to guess what that
would cost.

As much as the spot welder that does the pinout wires on a 25c chip perhaps?


Also, solder is reliable enough in this context for the design life - say
about 5 years.

FWIW, the harnesses going to those PCBs will invariably have crimped
plugs.


Mmm. And all those moon rockets and NASA stuff just FULL of soldered joints?

Thanks everyone for the helpful comments, I feel more confident about
tackling my first job with crimp joints now.

I'll stick to the idea of crimps rather than solder, I don't think my
soldering technique for smallish electronic stuff would scale up to 2.5
& 4 mm^2 cable very well.

--
Mike Clarke

"Pete C" wrote
| If you partly cover the intake on a hairdryer it should be hot
| enough to do the heatshrink - or possibly even catch fire!

I noticed a nice violet glow from something inside the vacuum cleaner this
morning.

Owain

In message , "Dave Plowman (News)"
writes
In article ,
The Natural Philosopher wrote:
If crimps are so darned good, why don;t we have crimpable chips
resitsiors, capaitors abnd circuit borads?

Cost of production. You can flow solder over an entire PCB in one go. And
do many PCBs at the same time.
Each crimp would have to be made individually, or with a machine which
did several at once - and it doesn't take imagination to guess what that
would cost.

Also, solder is reliable enough in this context for the design life - say
about 5 years.

FWIW, the harnesses going to those PCBs will invariably have crimped
plugs.

Which are prone to breaking - quite a common problem in boilers

--
geoff

In message , The Natural
Philosopher writes
Dave Plowman (News) wrote:

In article ,
The Natural Philosopher wrote:

If crimps are so darned good, why don;t we have crimpable chips
resitsiors, capaitors abnd circuit borads?
Cost of production. You can flow solder over an entire PCB in one
go. And
do many PCBs at the same time.
Each crimp would have to be made individually, or with a machine which
did several at once - and it doesn't take imagination to guess what that
would cost.

As much as the spot welder that does the pinout wires on a 25c chip perhaps?

Also, solder is reliable enough in this context for the design life
- say
about 5 years.
FWIW, the harnesses going to those PCBs will invariably have crimped
plugs.


Mmm. And all those moon rockets and NASA stuff just FULL of soldered joints?

But they are not flow soldered and they are all individually inspected

--
geoff

In article ,
raden wrote:
FWIW, the harnesses going to those PCBs will invariably have crimped
plugs.

Which are prone to breaking - quite a common problem in boilers

Badly designed cable clamps on the connectors then and or rough handling.

Whatever the pros and cons, one thing is certain. A soldered joint is far
more likely to fracture than a crimped one. A properly made crimp should
hardly weaken the cable at all.

--
*Xerox and Wurlitzer will merge to market reproductive organs.

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

In message , "Dave Plowman (News)"
writes
In article ,
raden wrote:
FWIW, the harnesses going to those PCBs will invariably have crimped
plugs.

Which are prone to breaking - quite a common problem in boilers

Badly designed cable clamps on the connectors then and or rough handling.

You don't say ...

vibration and CH fitters ...

--
geoff

In article ,
raden wrote:
Which are prone to breaking - quite a common problem in boilers

Badly designed cable clamps on the connectors then and or rough
handling.

You don't say ...

vibration and CH fitters ...

And poorly specified cable and or connectors. Not that you're at all
worried. ;-)

--
* I like you. You remind me of when I was young and stupid

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

On Tue, 28 Sep 2004 22:53:16 +0100, The Natural Philosopher
wrote:

And, a crimp is totally dependent on how well its made. Its a bit harder
to make a complete mess of solder as long as the iron is hot...

You are joking I trust? You and I can make perfect joints, but you
should see the attempts of a novice. It takes practice and dedication.
It is the lack of the latter that is the problem. Given a crimp and
decent ratchet crimper all you need to do is trim the wire to the
correct length and make sure it goes fully into the crimp .

Phil
The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/
Remove NOSPAM from address to email me

On Wed, 29 Sep 2004 06:22:39 +0100, The Natural Philosopher
wrote:

Dave Plowman (News) wrote:

In article ,
The Natural Philosopher wrote:

And, a crimp is totally dependent on how well its made.


Using the normal crimps and the correct tool it's a bit difficult to get
it wrong...


Its a bit harder
to make a complete mess of solder as long as the iron is hot...


Then just about every factory manages it - given the number of solder
faults you get on older electronic equipment. Including those not subject
to excessive heat and vibration.

Thermal cycling. I forgot thermal cycling. Nasty on solder joints
especially if they are under tensin from a crop-and-bend machine.

If crimps are so darned good, why don;t we have crimpable chips
resitsiors, capaitors abnd circuit borads?

A good crimp is good on electrcal conductvity, on vibration resistance
and on thermal cycling.

But it can fail like anything else. on stranded wire its potentally more
subject to corrosion as well, as moisture can get trapped in the strands..

True. You can use an encapsulating oversleeve if that is an expected
environment.

Wiring looms in aircaftt are not subject to the same set of conditions
as mains wires in walls, and are totally dissimilar from mass produced
crcuit boards in consumer equipment.

Of course.

And trained aircfart technicians using proper equipment and subject to
rigourous testing are not the same as half trained gibbons squeezing
crimps with pliers and shoving them in a wall to be plstered over.

The point being? That gibbons can do better with a cruddy soldering
iron?

Phil
The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/
Remove NOSPAM from address to email me

On Wed, 29 Sep 2004 09:55:54 +0100, "Dave Plowman (News)"
wrote:

In article ,
The Natural Philosopher wrote:
If crimps are so darned good, why don;t we have crimpable chips
resitsiors, capaitors abnd circuit borads?

Cost of production. You can flow solder over an entire PCB in one go. And
do many PCBs at the same time.
Each crimp would have to be made individually, or with a machine which
did several at once - and it doesn't take imagination to guess what that
would cost.

It would also be quite hard to get crimp joint small enough to fit 468
under a pentium chip!

Phil
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Phil Addison wrote:

On Tue, 28 Sep 2004 22:53:16 +0100, The Natural Philosopher
wrote:


And, a crimp is totally dependent on how well its made. Its a bit harder
to make a complete mess of solder as long as the iron is hot...


You are joking I trust? You and I can make perfect joints, but you
should see the attempts of a novice. It takes practice and dedication.
It is the lack of the latter that is the problem. Given a crimp and
decent ratchet crimper all you need to do is trim the wire to the
correct length and make sure it goes fully into the crimp .

Even that is too advanced for the average simian who does electrical
installations IMHO :-)


Phil
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Phil Addison wrote:

On Wed, 29 Sep 2004 06:22:39 +0100, The Natural Philosopher
wrote:


Dave Plowman (News) wrote:


In article ,
The Natural Philosopher wrote:


And, a crimp is totally dependent on how well its made.


Using the normal crimps and the correct tool it's a bit difficult to get
it wrong...



Its a bit harder
to make a complete mess of solder as long as the iron is hot...


Then just about every factory manages it - given the number of solder
faults you get on older electronic equipment. Including those not subject
to excessive heat and vibration.


Thermal cycling. I forgot thermal cycling. Nasty on solder joints
especially if they are under tensin from a crop-and-bend machine.

If crimps are so darned good, why don;t we have crimpable chips
resitsiors, capaitors abnd circuit borads?

A good crimp is good on electrcal conductvity, on vibration resistance
and on thermal cycling.

But it can fail like anything else. on stranded wire its potentally more
subject to corrosion as well, as moisture can get trapped in the strands..


True. You can use an encapsulating oversleeve if that is an expected
environment.


Wiring looms in aircaftt are not subject to the same set of conditions
as mains wires in walls, and are totally dissimilar from mass produced
crcuit boards in consumer equipment.


Of course.


And trained aircfart technicians using proper equipment and subject to
rigourous testing are not the same as half trained gibbons squeezing
crimps with pliers and shoving them in a wall to be plstered over.


The point being? That gibbons can do better with a cruddy soldering
iron?


No, that a competent D-I-Y er can.

Gibbons **** up everything.

Phil
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On Thu, 30 Sep 2004 11:38:06 +0100, The Natural Philosopher
wrote:

And, a crimp is totally dependent on how well its made. Its a bit harder
to make a complete mess of solder as long as the iron is hot...


You are joking I trust? You and I can make perfect joints, but you
should see the attempts of a novice. It takes practice and dedication.
It is the lack of the latter that is the problem. Given a crimp and
decent ratchet crimper all you need to do is trim the wire to the
correct length and make sure it goes fully into the crimp .

Even that is too advanced for the average simian who does electrical
installations IMHO :-)

We are talking about diyers competent enough to get here, not apes or
monkeys.

Phil
The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/
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On 30 Sep 2004 The Natural Philosopher wrote:

Phil Addison wrote:

On Wed, 29 Sep 2004 06:22:39 +0100, The Natural Philosopher
wrote:

And trained aircfart technicians using proper equipment and
subject to rigourous testing are not the same as half trained
gibbons squeezing crimps with pliers and shoving them in a wall
to be plstered over.

The point being? That gibbons can do better with a cruddy soldering
iron?


No, that a competent D-I-Y er can.

Gibbons **** up everything.

If you gave an infinite number of monkeys an infinite number of
soldering irons they would eventually make an IBM PC.



So THAT'S how they do it ;-)

--
Richard Porter
Mail to username ricp at domain minijem.plus.com
"You can't have Windows without pains."

Richard Porter wrote:

On 30 Sep 2004 The Natural Philosopher wrote:


Phil Addison wrote:


On Wed, 29 Sep 2004 06:22:39 +0100, The Natural Philosopher
wrote:


And trained aircfart technicians using proper equipment and
subject to rigourous testing are not the same as half trained
gibbons squeezing crimps with pliers and shoving them in a wall
to be plstered over.

The point being? That gibbons can do better with a cruddy soldering
iron?


No, that a competent D-I-Y er can.

Gibbons **** up everything.


If you gave an infinite number of monkeys an infinite number of
soldering irons they would eventually make an IBM PC.



Odd. I rather thought that's where it all came from in the first place...

Actually, they would have evolved into IMM before they did that.


So THAT'S how they do it ;-)

In message , "Dave Plowman (News)"
writes
In article ,
raden wrote:
Which are prone to breaking - quite a common problem in boilers

Badly designed cable clamps on the connectors then and or rough
handling.

You don't say ...

vibration and CH fitters ...

And poorly specified cable and or connectors. Not that you're at all
worried. ;-)

Not so.

E.g. last week, I sent out a Suprima pcb, and got a phone call saying it
didn't work, the board keeps going into lockout just like the other one.

I sent another board out and got the first one I sent back - no problem
with it

.... "Ah yes, I found there was a break in the HT lead"

This wasn't an isolated example

--
geoff

In message , The Natural
Philosopher writes
Phil Addison wrote:

On Tue, 28 Sep 2004 22:53:16 +0100, The Natural Philosopher
wrote:

And, a crimp is totally dependent on how well its made. Its a bit
harder to make a complete mess of solder as long as the iron is hot...
You are joking I trust? You and I can make perfect joints, but you
should see the attempts of a novice. It takes practice and dedication.
It is the lack of the latter that is the problem. Given a crimp and
decent ratchet crimper all you need to do is trim the wire to the
correct length and make sure it goes fully into the crimp .

Even that is too advanced for the average simian who does electrical
installations IMHO :-)

Or the invertebrates who try and repair pcbs with plumbers solder !

--
geoff