We have a load of lampshades which are made from loops of metal with (I
think) plastic inside - like little portholes.

http://s817.photobucket.com/user/Lit...trange%20bits/
Lampshade%20Soldering/Lampshade.jpg.html

As far as I can tell all the circles of different sizes are soldered
together, then the ring to fit onto the light fitting is soldered on with
three little wire arms.

One of these wire arms has become detached from the ring.

I am attempting to solder it back, but not doing too well.

My biggest soldering iron is 45W but this doesn't seem to be able to get
enough heat in to solder to the ring. It will melt the solder on the wire,
but that won't stick to the much large expanse of metal. I've tried
heating the ring from the back in the hope that the solder will flow, but
nothing.

Next up in the power stakes is my pen torch (gas powered).

https://www.amazon.co.uk/Pencil-Buta.../dp/B004K7ME5S

This seems to be a bit too powerful. Certainly hot. Solder just blows away
in the flame as far as I can tell.

So how do the manufacturers make these things?

Is there something in between (perhaps 60W or more) which will give enough
local heat or am I scuppered because the ring part conducts the heat away
too quickly?

Is there an alternative such as an adhesive which might work? Tiny bit of
body filler perhaps?

Cheers


Dave R

--
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On Sun, 01 Apr 2018 17:23:48 +0000, David wrote:

We have a load of lampshades which are made from loops of metal with (I
think) plastic inside - like little portholes.

http://s817.photobucket.com/user/Lit...trange%20bits/
Lampshade%20Soldering/Lampshade.jpg.html

As far as I can tell all the circles of different sizes are soldered
together, then the ring to fit onto the light fitting is soldered on
with three little wire arms.

One of these wire arms has become detached from the ring.

I am attempting to solder it back, but not doing too well.

My biggest soldering iron is 45W but this doesn't seem to be able to get
enough heat in to solder to the ring. It will melt the solder on the
wire,
but that won't stick to the much large expanse of metal. I've tried
heating the ring from the back in the hope that the solder will flow,
but nothing.

Next up in the power stakes is my pen torch (gas powered).

https://www.amazon.co.uk/Pencil-Buta.../dp/B004K7ME5S

This seems to be a bit too powerful. Certainly hot. Solder just blows
away in the flame as far as I can tell.

So how do the manufacturers make these things?

Is there something in between (perhaps 60W or more) which will give
enough local heat or am I scuppered because the ring part conducts the
heat away too quickly?

Is there an alternative such as an adhesive which might work? Tiny bit
of body filler perhaps?

O.K. - should have looked more closely on line instead of accepting that
30W is normal and 45W is large.

Plenty of 100W soldering irons for not much money, but 120W gets a tad
expensive.

So I think I should rephrase the question into "how much power am I likely
to need to spot heat this kind of structure".

I assume that I have to get the heat in locally very quickly so it doesn't
just dissipate into the rest of the metal.

Cheers



Dave R


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David laid this down on his screen :
O.K. - should have looked more closely on line instead of accepting that
30W is normal and 45W is large.

Plenty of 100W soldering irons for not much money, but 120W gets a tad
expensive.

A true 100w should manage it, but don't expect one of those instant
trigger type 100w irons to cope. Like a gun, with a trigger and and a
copper loop type element.

Whether soldering might be enough, is a different story. I suspect
originally it will have been spot welded. You might be better looking
up how to try that, with a 12v car battery.

On 01/04/2018 18:59, Harry Bloomfield wrote:
David laid this down on his screen :
O.K. - should have looked more closely on line instead of accepting that
30W is normal and 45W is large.

Plenty of 100W soldering irons for not much money, but 120W gets a tad
expensive.

A true 100w should manage it, but don't expect one of those instant
trigger type 100w irons to cope. Like a gun, with a trigger and and a
copper loop type element.

Whether soldering might be enough, is a different story. I suspect
originally it will have been spot welded. You might be better looking up
how to try that, with a 12v car battery.

If it is plastic, you will have problems with that melting. I thought
these things were sometimes some sort of shell.

Given that the repair shouldn't be particularly visible, I'd be inclined
to use a blob of epoxy.

On Sunday, 1 April 2018 19:07:50 UTC+1, newshound wrote:
On 01/04/2018 18:59, Harry Bloomfield wrote:
David laid this down on his screen :
O.K. - should have looked more closely on line instead of accepting that
30W is normal and 45W is large.

Plenty of 100W soldering irons for not much money, but 120W gets a tad
expensive.

A true 100w should manage it, but don't expect one of those instant
trigger type 100w irons to cope. Like a gun, with a trigger and and a
copper loop type element.

Whether soldering might be enough, is a different story. I suspect
originally it will have been spot welded. You might be better looking up
how to try that, with a 12v car battery.

If it is plastic, you will have problems with that melting. I thought
these things were sometimes some sort of shell.

Given that the repair shouldn't be particularly visible, I'd be inclined
to use a blob of epoxy.

+2. I wouldn't even consider soldering while the plastic inserts are in place.


NT

David wrote:
Is there something in between (perhaps 60W or more) which will give enough
local heat or am I scuppered because the ring part conducts the heat away
too quickly?

Notwithstanding the issue about melting or damaging the inserts, I think
you'd probably OK to solder the rings with a 45W iron. Maybe a little on
the low side, but should be OK.

What's you're missing is flux. The surface is probably dirty, maybe
painted. You need to get back to clean metal so that solder flows on the
surface. You don't melt solder on the iron, you heat the metal and feed
metal onto the surface. The only purpose of solder on the bit of the iron
is to ensure good heat conductivity from the bit to the workpiece.

Likewise with a gas torch, you don't wave the solder into the flame, you
heat up the metal and pool molten solder on the surface. However, I think a
gas torch is way overpowered here and difficult to control.

Flux is the key to getting solder to stick to metal, particularly oxidised
metal. You can use plumber's flux, but liquid flux is less viscous and
easier to apply thinly:
https://www.ebay.co.uk/itm/Electrolu...e/130962877320

The symptom of not-enough-heat is when solder on the bit solidifies when you
touch the workpiece, and stays solidified no matter how long you hold it, or
if you can melt solder on the workpiece close to the bit but not further
away. If you can melt solder on the bit but not on the workpiece, you have
a heat conductivity problem. If it doesn't stick, you have a flux problem.
(or have non-solderable metals)

Theo

On 01/04/2018 23:21, Theo wrote:

What's you're missing is flux. The surface is probably dirty, maybe
painted. You need to get back to clean metal so that solder flows on the
surface. You don't melt solder on the iron, you heat the metal and feed
metal onto the surface. The only purpose of solder on the bit of the iron
is to ensure good heat conductivity from the bit to the workpiece.

Likewise with a gas torch, you don't wave the solder into the flame, you
heat up the metal and pool molten solder on the surface. However, I think a
gas torch is way overpowered here and difficult to control.

Flux is the key to getting solder to stick to metal, particularly oxidised
metal. You can use plumber's flux, but liquid flux is less viscous and
easier to apply thinly:
https://www.ebay.co.uk/itm/Electrolu...e/130962877320

The symptom of not-enough-heat is when solder on the bit solidifies when you
touch the workpiece, and stays solidified no matter how long you hold it, or
if you can melt solder on the workpiece close to the bit but not further
away. If you can melt solder on the bit but not on the workpiece, you have
a heat conductivity problem. If it doesn't stick, you have a flux problem.
(or have non-solderable metals)


Also use tin/lead (60/40) solder rather than lead free solder. The
former requires a temperature of around 190C whereas the latter
typically 220C.

It may be beneficial to have a mechanical join before soldering. A turn
of thin fuse wire or one strand from a multi-strand wire flex.


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On Sun, 01 Apr 2018 23:40:52 +0100, alan_m wrote:

Also use tin/lead (60/40) solder rather than lead free solder. The
former requires a temperature of around 190C whereas the latter
typically 220C.

Even better, if you can get it, 63/37 tin/lead solder. Lower melting
point, and the liquid to solid transition is fast.

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wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

In article ,
David wrote:
We have a load of lampshades which are made from loops of metal with (I
think) plastic inside - like little portholes.

http://s817.photobucket.com/user/Lit...trange%20bits/
Lampshade%20Soldering/Lampshade.jpg.html

As far as I can tell all the circles of different sizes are soldered
together, then the ring to fit onto the light fitting is soldered on with
three little wire arms.

One of these wire arms has become detached from the ring.

I am attempting to solder it back, but not doing too well.

My biggest soldering iron is 45W but this doesn't seem to be able to get
enough heat in to solder to the ring. It will melt the solder on the wire,
but that won't stick to the much large expanse of metal. I've tried
heating the ring from the back in the hope that the solder will flow, but
nothing.

Next up in the power stakes is my pen torch (gas powered).

https://www.amazon.co.uk/Pencil-Buta.../dp/B004K7ME5S

This seems to be a bit too powerful. Certainly hot. Solder just blows away
in the flame as far as I can tell.

So how do the manufacturers make these things?

Is there something in between (perhaps 60W or more) which will give enough
local heat or am I scuppered because the ring part conducts the heat away
too quickly?

Is there an alternative such as an adhesive which might work? Tiny bit of
body filler perhaps?

Cheers


Dave R

You could use a combination of then both. The gas flame to heat it just
enough so the iron can cope.

--
*Always drink upstream from the herd *

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

On 01/04/2018 23:21, Theo wrote:
David wrote:
Is there something in between (perhaps 60W or more) which will give enough
local heat or am I scuppered because the ring part conducts the heat away
too quickly?

Notwithstanding the issue about melting or damaging the inserts, I think
you'd probably OK to solder the rings with a 45W iron. Maybe a little on
the low side, but should be OK.

What's you're missing is flux. The surface is probably dirty, maybe
painted. You need to get back to clean metal so that solder flows on the
surface. You don't melt solder on the iron, you heat the metal and feed
metal onto the surface. The only purpose of solder on the bit of the iron
is to ensure good heat conductivity from the bit to the workpiece.

Likewise with a gas torch, you don't wave the solder into the flame, you
heat up the metal and pool molten solder on the surface. However, I think a
gas torch is way overpowered here and difficult to control.

Flux is the key to getting solder to stick to metal, particularly oxidised
metal. You can use plumber's flux, but liquid flux is less viscous and
easier to apply thinly:
https://www.ebay.co.uk/itm/Electrolu...e/130962877320

The symptom of not-enough-heat is when solder on the bit solidifies when you
touch the workpiece, and stays solidified no matter how long you hold it, or
if you can melt solder on the workpiece close to the bit but not further
away. If you can melt solder on the bit but not on the workpiece, you have
a heat conductivity problem. If it doesn't stick, you have a flux problem.
(or have non-solderable metals)

Yup, what he said...

If you want a glue instead, then JB Weld two part epoxy.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 01/04/18 18:30, David wrote:
So I think I should rephrase the question into "how much power am I likely
to need to spot heat this kind of structure".

It's less power, than a very large bit, that wont cool down immediately
it hits that ring


--
Those who want slavery should have the grace to name it by its proper
name. They must face the full meaning of that which they are advocating
or condoning; the full, exact, specific meaning of collectivism, of its
logical implications, of the principles upon which it is based, and of
the ultimate consequences to which these principles will lead. They must
face it, then decide whether this is what they want or not.

Ayn Rand.

What metal is it? Soldering is quite a complex thing, as soldering
dissimilar metals often needs special flux and sometimes different solder as
well.

Brian

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Blind user, so no pictures please!
"David" wrote in message
...
On Sun, 01 Apr 2018 17:23:48 +0000, David wrote:

We have a load of lampshades which are made from loops of metal with (I
think) plastic inside - like little portholes.

http://s817.photobucket.com/user/Lit...trange%20bits/
Lampshade%20Soldering/Lampshade.jpg.html

As far as I can tell all the circles of different sizes are soldered
together, then the ring to fit onto the light fitting is soldered on
with three little wire arms.

One of these wire arms has become detached from the ring.

I am attempting to solder it back, but not doing too well.

My biggest soldering iron is 45W but this doesn't seem to be able to get
enough heat in to solder to the ring. It will melt the solder on the
wire,
but that won't stick to the much large expanse of metal. I've tried
heating the ring from the back in the hope that the solder will flow,
but nothing.

Next up in the power stakes is my pen torch (gas powered).

https://www.amazon.co.uk/Pencil-Buta.../dp/B004K7ME5S

This seems to be a bit too powerful. Certainly hot. Solder just blows
away in the flame as far as I can tell.

So how do the manufacturers make these things?

Is there something in between (perhaps 60W or more) which will give
enough local heat or am I scuppered because the ring part conducts the
heat away too quickly?

Is there an alternative such as an adhesive which might work? Tiny bit
of body filler perhaps?

O.K. - should have looked more closely on line instead of accepting that
30W is normal and 45W is large.

Plenty of 100W soldering irons for not much money, but 120W gets a tad
expensive.

So I think I should rephrase the question into "how much power am I likely
to need to spot heat this kind of structure".

I assume that I have to get the heat in locally very quickly so it doesn't
just dissipate into the rest of the metal.

Cheers



Dave R


--
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Or even wire the two bits together using solder, assuming its not too
visible and not needing to be mega strong.
Brian

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"newshound" wrote in message
...
On 01/04/2018 18:59, Harry Bloomfield wrote:
David laid this down on his screen :
O.K. - should have looked more closely on line instead of accepting that
30W is normal and 45W is large.

Plenty of 100W soldering irons for not much money, but 120W gets a tad
expensive.

A true 100w should manage it, but don't expect one of those instant
trigger type 100w irons to cope. Like a gun, with a trigger and and a
copper loop type element.

Whether soldering might be enough, is a different story. I suspect
originally it will have been spot welded. You might be better looking up
how to try that, with a 12v car battery.

If it is plastic, you will have problems with that melting. I thought
these things were sometimes some sort of shell.

Given that the repair shouldn't be particularly visible, I'd be inclined
to use a blob of epoxy.

On Sun, 01 Apr 2018 23:21:33 +0100, Theo wrote:

David wrote:
snip
The symptom of not-enough-heat is when solder on the bit solidifies when
you touch the workpiece, and stays solidified no matter how long you
hold it, or if you can melt solder on the workpiece close to the bit but
not further away. If you can melt solder on the bit but not on the
workpiece, you have a heat conductivity problem. If it doesn't stick,
you have a flux problem.
(or have non-solderable metals)

Pretty much describes it - I can melt solder next to the metal, but not by
applying the iron directly to the metal.

Which is why I tentatively concluded that it is a "lack of heat" issue.

On the back burner at the moment because I realised I have an identical
shade in my bedroom so this is now a replacement in the living room.

Set of matching shades in the living room so replacement would have been
tricky as The Range isn't showing them for sale at the moment.

Cheers


Dave R


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On Sun, 01 Apr 2018 18:59:16 +0100, Harry Bloomfield wrote:

David laid this down on his screen :
O.K. - should have looked more closely on line instead of accepting
that 30W is normal and 45W is large.

Plenty of 100W soldering irons for not much money, but 120W gets a tad
expensive.

A true 100w should manage it, but don't expect one of those instant
trigger type 100w irons to cope. Like a gun, with a trigger and and a
copper loop type element.

Whether soldering might be enough, is a different story. I suspect
originally it will have been spot welded. You might be better looking up
how to try that, with a 12v car battery.

I know it isn't spot welded because I melted the original solder - solder
flows and sets in quite a distinctive way, as well.

For those commenting on the circles and solder, please note that I am
taking about the ring that fits on the pendant light socket with a screw
on plastic ring to hold it in place. So no soldering anywhere near other
materials, thankfully.


Cheers



Dave R


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David wrote:
For those commenting on the circles and solder, please note that I am
taking about the ring that fits on the pendant light socket with a screw
on plastic ring to hold it in place. So no soldering anywhere near other
materials, thankfully.

In which case, I'd say more than 45W is required. The gas torch might do
it, but it'll be pretty tricky to control.

I bought one of these while they were 9.99:
https://www.maplin.co.uk/p/maplin-10...ing-iron-n00dp

I didn't use it for soldering, but the element is like a red hot poker so I
think it would do the job. It has quite a high thermal mass so the tip
isn't likely to cool much when you touch something cold.

Theo

On Monday, 2 April 2018 12:38:13 UTC+1, David WE Roberts (Google) wrote:
On Sun, 01 Apr 2018 18:59:16 +0100, Harry Bloomfield wrote:
David laid this down on his screen :

O.K. - should have looked more closely on line instead of accepting
that 30W is normal and 45W is large.

Plenty of 100W soldering irons for not much money, but 120W gets a tad
expensive.

A true 100w should manage it, but don't expect one of those instant
trigger type 100w irons to cope. Like a gun, with a trigger and and a
copper loop type element.

Whether soldering might be enough, is a different story. I suspect
originally it will have been spot welded. You might be better looking up
how to try that, with a 12v car battery.

I know it isn't spot welded because I melted the original solder - solder
flows and sets in quite a distinctive way, as well.

For those commenting on the circles and solder, please note that I am
taking about the ring that fits on the pendant light socket with a screw
on plastic ring to hold it in place. So no soldering anywhere near other
materials, thankfully.


Cheers



Dave R

Ah, then forget solder, it's a very weak material.


NT