So many of these lead failures, not solder problems
There must be a better way - at production, yes, using large diameter hollow
tube "beefings" and larger pcb solder pads and holes.
But retrofit ?
I'm assuming the oscillation mode is transverse to the resistor axis rather
than axially rocking. If laid against the pcb then the ceramic "feet" act as
leverage when rocking and if elevated off the board then extra momentum also
amplify the rupture force at the point where the leads go through the board.
This is my latest attempt. I have hundreds of these hermaphroditic
Varelco, Elco, Edac (DERA company, over-shelflife disposal) like in pic
http://www.dhaen.org.uk/vdocs/Onryok...es/varelco.jpg
(in the bag )
I could find no other pics on the net.
The flat part is the mating part so they can mate like 2 finfgers of one
hand rotated 90 degrees and mating twith 2 fingers of your other hand, so no
male/female specificity. A pair of these gold plated brass contacts with one
of the 2 fingers cut off with snips . Matching side with side so when
crimped and soldered to the resistor leads , facing opposite directions,
they are, locked against rocking, against the board.
It will still be a weak point at or in the pcb hole but will they be more
resistant to fracture than the usual resistor lead metal ?


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:
So many of these lead failures, not solder problems
There must be a better way - at production, yes, using large diameter hollow
tube "beefings" and larger pcb solder pads and holes.
But retrofit ?
I'm assuming the oscillation mode is transverse to the resistor axis rather
than axially rocking. If laid against the pcb then the ceramic "feet" act as
leverage when rocking and if elevated off the board then extra momentum also
amplify the rupture force at the point where the leads go through the board.
This is my latest attempt. I have hundreds of these hermaphroditic
Varelco, Elco, Edac (DERA company, over-shelflife disposal) like in pic
http://www.dhaen.org.uk/vdocs/Onryok...es/varelco.jpg
(in the bag )
I could find no other pics on the net.
The flat part is the mating part so they can mate like 2 finfgers of one
hand rotated 90 degrees and mating twith 2 fingers of your other hand, so no
male/female specificity. A pair of these gold plated brass contacts with one
of the 2 fingers cut off with snips . Matching side with side so when
crimped and soldered to the resistor leads , facing opposite directions,
they are, locked against rocking, against the board.
It will still be a weak point at or in the pcb hole but will they be more
resistant to fracture than the usual resistor lead metal ?

Mount the resistor in a custom build anodised aluminium cradle, perched
on small springs with tiny hydraulic dampers to absorb any shock. Note
that the springs will need to be thermally insulated from the resistor
cradle to avoid any possibility of temper change through heat transference.

Hard wire the resistor to the board with mil spec extra flexible cable.
http://www.awcwire.com/ProductSpec.a...=Rope-QQ-B-575

The connections should be both spot welded and soldered. The soldered
connections being made in accordance with NASA specifications -
available here http://www.hq.nasa.gov/office/codeq/sldrbch1.pdf

Re designating the guitar combo as military or aviation equipment will
allow you to use tin/lead solder as per NASA specs

Hope this Helps

Ron(UK)

"Ron(UK)" wrote in message
...
N Cook wrote:
So many of these lead failures, not solder problems
There must be a better way - at production, yes, using large diameter
hollow
tube "beefings" and larger pcb solder pads and holes.
But retrofit ?
I'm assuming the oscillation mode is transverse to the resistor axis
rather
than axially rocking. If laid against the pcb then the ceramic "feet" act
as
leverage when rocking and if elevated off the board then extra momentum
also
amplify the rupture force at the point where the leads go through the
board.
This is my latest attempt. I have hundreds of these hermaphroditic
Varelco, Elco, Edac (DERA company, over-shelflife disposal) like in pic
http://www.dhaen.org.uk/vdocs/Onryok...es/varelco.jpg
(in the bag )
I could find no other pics on the net.
The flat part is the mating part so they can mate like 2 finfgers of one
hand rotated 90 degrees and mating twith 2 fingers of your other hand, so
no
male/female specificity. A pair of these gold plated brass contacts with
one
of the 2 fingers cut off with snips . Matching side with side so when
crimped and soldered to the resistor leads , facing opposite directions,
they are, locked against rocking, against the board.
It will still be a weak point at or in the pcb hole but will they be more
resistant to fracture than the usual resistor lead metal ?

Mount the resistor in a custom build anodised aluminium cradle, perched on
small springs with tiny hydraulic dampers to absorb any shock. Note that
the springs will need to be thermally insulated from the resistor cradle
to avoid any possibility of temper change through heat transference.

Hard wire the resistor to the board with mil spec extra flexible cable.
http://www.awcwire.com/ProductSpec.a...=Rope-QQ-B-575

The connections should be both spot welded and soldered. The soldered
connections being made in accordance with NASA specifications - available
here http://www.hq.nasa.gov/office/codeq/sldrbch1.pdf

Re designating the guitar combo as military or aviation equipment will
allow you to use tin/lead solder as per NASA specs

Hope this Helps

Ron(UK)

Oh Ron, you naughty little tinker you ... :~)

Arfa

Arfa Daily wrote:
"Ron(UK)" wrote in message
...
N Cook wrote:
So many of these lead failures, not solder problems
There must be a better way - at production, yes, using large diameter
hollow
tube "beefings" and larger pcb solder pads and holes.
But retrofit ?
I'm assuming the oscillation mode is transverse to the resistor axis
rather
than axially rocking. If laid against the pcb then the ceramic "feet" act
as
leverage when rocking and if elevated off the board then extra momentum
also
amplify the rupture force at the point where the leads go through the
board.
This is my latest attempt. I have hundreds of these hermaphroditic
Varelco, Elco, Edac (DERA company, over-shelflife disposal) like in pic
http://www.dhaen.org.uk/vdocs/Onryok...es/varelco.jpg
(in the bag )
I could find no other pics on the net.
The flat part is the mating part so they can mate like 2 finfgers of one
hand rotated 90 degrees and mating twith 2 fingers of your other hand, so
no
male/female specificity. A pair of these gold plated brass contacts with
one
of the 2 fingers cut off with snips . Matching side with side so when
crimped and soldered to the resistor leads , facing opposite directions,
they are, locked against rocking, against the board.
It will still be a weak point at or in the pcb hole but will they be more
resistant to fracture than the usual resistor lead metal ?
Mount the resistor in a custom build anodised aluminium cradle, perched on
small springs with tiny hydraulic dampers to absorb any shock. Note that
the springs will need to be thermally insulated from the resistor cradle
to avoid any possibility of temper change through heat transference.

Hard wire the resistor to the board with mil spec extra flexible cable.
http://www.awcwire.com/ProductSpec.a...=Rope-QQ-B-575

The connections should be both spot welded and soldered. The soldered
connections being made in accordance with NASA specifications - available
here http://www.hq.nasa.gov/office/codeq/sldrbch1.pdf

Re designating the guitar combo as military or aviation equipment will
allow you to use tin/lead solder as per NASA specs

Hope this Helps

Ron(UK)

Oh Ron, you naughty little tinker you ... :~)

Well personally, I just resolder them.

Ron(UK)

Ron(UK) wrote in message
...
Arfa Daily wrote:
"Ron(UK)" wrote in message
...
N Cook wrote:
So many of these lead failures, not solder problems
There must be a better way - at production, yes, using large diameter
hollow
tube "beefings" and larger pcb solder pads and holes.
But retrofit ?
I'm assuming the oscillation mode is transverse to the resistor axis
rather
than axially rocking. If laid against the pcb then the ceramic "feet"
act
as
leverage when rocking and if elevated off the board then extra
momentum
also
amplify the rupture force at the point where the leads go through the
board.
This is my latest attempt. I have hundreds of these hermaphroditic
Varelco, Elco, Edac (DERA company, over-shelflife disposal) like in
pic
http://www.dhaen.org.uk/vdocs/Onryok...es/varelco.jpg
(in the bag )
I could find no other pics on the net.
The flat part is the mating part so they can mate like 2 finfgers of
one
hand rotated 90 degrees and mating twith 2 fingers of your other hand,
so
no
male/female specificity. A pair of these gold plated brass contacts
with
one
of the 2 fingers cut off with snips . Matching side with side so when
crimped and soldered to the resistor leads , facing opposite
directions,
they are, locked against rocking, against the board.
It will still be a weak point at or in the pcb hole but will they be
more
resistant to fracture than the usual resistor lead metal ?
Mount the resistor in a custom build anodised aluminium cradle, perched
on
small springs with tiny hydraulic dampers to absorb any shock. Note
that
the springs will need to be thermally insulated from the resistor
cradle
to avoid any possibility of temper change through heat transference.

Hard wire the resistor to the board with mil spec extra flexible cable.
http://www.awcwire.com/ProductSpec.a...=Rope-QQ-B-575

The connections should be both spot welded and soldered. The soldered
connections being made in accordance with NASA specifications -
available
here http://www.hq.nasa.gov/office/codeq/sldrbch1.pdf

Re designating the guitar combo as military or aviation equipment will
allow you to use tin/lead solder as per NASA specs

Hope this Helps

Ron(UK)

Oh Ron, you naughty little tinker you ... :~)

Well personally, I just resolder them.

Ron(UK)

Perhaps it was you who "repaired" this Fender previously.
I don't like bouncing repairs in the complaint sense.
Whoever, resoldered an already weakened ceramic W/W lead so it broke in the
pcb hole this time.
Perhaps multi-stranded copper wire bulked up with swathing in solder is the
material of choice for these component leads.
Obviously coppery metal work hardens and fractures, brass probably does too
if it moves.
What metal of small cross section that is solderable, not corrodable , and
survives vibration/oscillation/work hardening ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:

So many of these lead failures, not solder problems
There must be a better way - at production, yes, using large diameter hollow
tube "beefings" and larger pcb solder pads and holes.
But retrofit ?

snip

I like to use gold-plated square posts on the pcb and salvaged Berg
female connector pins on the fragile components leads; shock, flexing
and vibration will produce other failure modes before ruining a
part so mounted.

Regards,

Michael

Meat Plow wrote:
On Thu, 06 Sep 2007 09:01:54 +0100, N Cook wrote:

So many of these lead failures, not solder problems
There must be a better way - at production, yes, using large diameter hollow
tube "beefings" and larger pcb solder pads and holes.
But retrofit ?
I'm assuming the oscillation mode is transverse to the resistor axis rather
than axially rocking. If laid against the pcb then the ceramic "feet" act as
leverage when rocking and if elevated off the board then extra momentum also
amplify the rupture force at the point where the leads go through the board.
This is my latest attempt. I have hundreds of these hermaphroditic
Varelco, Elco, Edac (DERA company, over-shelflife disposal) like in pic
http://www.dhaen.org.uk/vdocs/Onryok...es/varelco.jpg
(in the bag )
I could find no other pics on the net.
The flat part is the mating part so they can mate like 2 finfgers of one
hand rotated 90 degrees and mating twith 2 fingers of your other hand, so no
male/female specificity. A pair of these gold plated brass contacts with one
of the 2 fingers cut off with snips . Matching side with side so when
crimped and soldered to the resistor leads , facing opposite directions,
they are, locked against rocking, against the board.
It will still be a weak point at or in the pcb hole but will they be more
resistant to fracture than the usual resistor lead metal ?

I guess they just don't make them like they used to? I've worked on many
many combo amps and can only recall one failure as you describe and it was
in my own Peavey Artist 120 circa 1975.


I bet that happened because the white gluey stuff they put on to
stabilise the part had dried out and cracked off, same goes for the
smoothing caps. I usually stabilise them with a squirt of high temp hot
melt glue, the woodworking stuff. When it gets hot it goes softer, but
doesn't run off like the clear type does.

I service amps that travel the length and breadth of the country
virtually non stop being professionally used. These failures are just a
part of life, beefing up one area probably means that something else
will fail elsewhere. Plus of course, modern stuff is junk compared to
that which was made 20/30/40 years ago

All IMHO of course

Ron(UK)

msg wrote in message
...
N Cook wrote:

So many of these lead failures, not solder problems
There must be a better way - at production, yes, using large diameter
hollow
tube "beefings" and larger pcb solder pads and holes.
But retrofit ?

snip

I like to use gold-plated square posts on the pcb and salvaged Berg
female connector pins on the fragile components leads; shock, flexing
and vibration will produce other failure modes before ruining a
part so mounted.

Regards,

Michael

Snap: I use what I think is the UK equivalent , 2 or 3 QM female pins slid
over the long wire of on-end large Rs to make more rigid when soldered in.
Can anyone identify the square section pins C,D,E in
http://home.graffiti.net/diverse:gra...t/varelco2.jpg
probably wire-wrap pins (1mm squares).
They are all much more rigid than the usual coppery wire leads to ceramic
Rs.
A and B are the Varelco pins that when one blade is cut off give a good
rigid mount when placed in opposite sense to block "rock and roll"

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote in message
...
msg wrote in message
...

graph paper is 1mm squares

Meat Plow wrote:
On Thu, 06 Sep 2007 17:13:14 +0100, Ron(UK) wrote:


I bet that happened because the white gluey stuff they put on to
stabilise the part had dried out and cracked off, same goes for the
smoothing caps. I usually stabilise them with a squirt of high temp hot
melt glue, the woodworking stuff. When it gets hot it goes softer, but
doesn't run off like the clear type does.

Seems to have been the cause of the failure IIRC. Have you used silicone
rubber? Seems like it would be a good choice.


Yes, silicone bath sealer works also . It just takes longer to set and
they might be a slight risk of corrosion from the acetic acid, tho
having said that, I`ve seen whole pcb`s potted in the stuff.

Ron(UK)

"Ron(UK)" wrote in message
...
Meat Plow wrote:
On Thu, 06 Sep 2007 09:01:54 +0100, N Cook wrote:

So many of these lead failures, not solder problems
There must be a better way - at production, yes, using large diameter
hollow
tube "beefings" and larger pcb solder pads and holes.
But retrofit ?
I'm assuming the oscillation mode is transverse to the resistor axis
rather
than axially rocking. If laid against the pcb then the ceramic "feet"
act as
leverage when rocking and if elevated off the board then extra momentum
also
amplify the rupture force at the point where the leads go through the
board.
This is my latest attempt. I have hundreds of these hermaphroditic
Varelco, Elco, Edac (DERA company, over-shelflife disposal) like in pic
http://www.dhaen.org.uk/vdocs/Onryok...es/varelco.jpg
(in the bag )
I could find no other pics on the net.
The flat part is the mating part so they can mate like 2 finfgers of one
hand rotated 90 degrees and mating twith 2 fingers of your other hand,
so no
male/female specificity. A pair of these gold plated brass contacts with
one
of the 2 fingers cut off with snips . Matching side with side so when
crimped and soldered to the resistor leads , facing opposite directions,
they are, locked against rocking, against the board.
It will still be a weak point at or in the pcb hole but will they be
more
resistant to fracture than the usual resistor lead metal ?

I guess they just don't make them like they used to? I've worked on many
many combo amps and can only recall one failure as you describe and it
was
in my own Peavey Artist 120 circa 1975.


I bet that happened because the white gluey stuff they put on to stabilise
the part had dried out and cracked off, same goes for the smoothing caps.
I usually stabilise them with a squirt of high temp hot melt glue, the
woodworking stuff. When it gets hot it goes softer, but doesn't run off
like the clear type does.

I service amps that travel the length and breadth of the country virtually
non stop being professionally used. These failures are just a part of
life, beefing up one area probably means that something else will fail
elsewhere. Plus of course, modern stuff is junk compared to that which
was made 20/30/40 years ago

All IMHO of course

Ron(UK)

I too mend a lot of this gear, and for sure, you are right that the modern
stuff, whilst being relatively just as expensive as that which was made in
the 60s and 70s, is nowhere near as well built. That said, I too agree that
failures of joints and leads on wirewound resitors is just par for the
course with the stuff - as was, as is, and as ever will be. I really don't
look on it as a big problem, and I'm sure that the musos just treat it all
as part of the rich tapestry of life on the road. If they haven't got a
spare amp with them, they just jack into the bass player's or whatever.
Whilst I would never just 'repair' a leg that had broken, as I'm sure that
Ron probably doesn't either, I'm sure that if the job is done properly, you
are not going to get a bounce, that is going to reflect badly on you. I
certainly don't see returns from doing such jobs.

I always enjoy Cooky's posts, and some of the fixes he comes up with, but
really, I do sometimes think that he is seeing problems that really don't
exist, and then finding fixes for them. Sorry mate, and no offense
intended - just the way I see it. :~)

Arfa

Arfa

"Ron(UK)" wrote in message
...
Meat Plow wrote:
On Thu, 06 Sep 2007 17:13:14 +0100, Ron(UK) wrote:


I bet that happened because the white gluey stuff they put on to
stabilise the part had dried out and cracked off, same goes for the
smoothing caps. I usually stabilise them with a squirt of high temp hot
melt glue, the woodworking stuff. When it gets hot it goes softer, but
doesn't run off like the clear type does.

Seems to have been the cause of the failure IIRC. Have you used silicone
rubber? Seems like it would be a good choice.


Yes, silicone bath sealer works also . It just takes longer to set and
they might be a slight risk of corrosion from the acetic acid, tho having
said that, I`ve seen whole pcb`s potted in the stuff.

Ron(UK)

I used to pot a whole board that I used to make for a company, in a
'flowing' silicon rubber. It got in and around and under every component on
the board, and then cured just like bath sealer, but without the acetic acid
smell. It was designed for electronic potting, so I guess it was corrosion
proof.

Arfa

"Meat Plow" wrote in message
...
On Thu, 06 Sep 2007 23:21:44 +0000, Arfa Daily wrote:


"Ron(UK)" wrote in message
...
Meat Plow wrote:
On Thu, 06 Sep 2007 17:13:14 +0100, Ron(UK) wrote:


I bet that happened because the white gluey stuff they put on to
stabilise the part had dried out and cracked off, same goes for the
smoothing caps. I usually stabilise them with a squirt of high temp
hot
melt glue, the woodworking stuff. When it gets hot it goes softer,
but
doesn't run off like the clear type does.

Seems to have been the cause of the failure IIRC. Have you used
silicone
rubber? Seems like it would be a good choice.


Yes, silicone bath sealer works also . It just takes longer to set and
they might be a slight risk of corrosion from the acetic acid, tho
having
said that, I`ve seen whole pcb`s potted in the stuff.

Ron(UK)

I used to pot a whole board that I used to make for a company, in a
'flowing' silicon rubber. It got in and around and under every component
on
the board, and then cured just like bath sealer, but without the acetic
acid
smell. It was designed for electronic potting, so I guess it was
corrosion
proof.


Isn't 100% pure silicon just that? Or is silicon naturally acetic? Would
"corrosion proof" silicon have an additive?

I think that the acetic acid thing is something to do with the curing
process. Presumably, this stuff used a different chemistry to arrive at the
result of it setting. I seem to recall it was a Dow Corning product, that I
bought from one of the big electronic component suppliers. It came in a
cartridge that you put in a standard builder's 'gun'. Came out of the nozzle
with about the consistency of treacle, and just flowed around the board and
self levelled. After about a half hour, during which time you had to keep an
eye on it to make sure that it wasn't running off the edge of the board, it
had gone to a sort of soft jelly state, and had skinned over. You could then
just leave it overnight, and by the next morning, it had gone off to that
really tough, but still flexible state, that you find where they've used
such stuff as the insulating infill on FBTx's and triplers and the like.
Unlike bath sealer, it stuck like **** to a blanket, and had a really strong
peel resistance. There was no chance of repairing a board that had been
covered with it - ever ...

The board was a counter that I was 'ringing' for a friend's company, and
this protection method was what was used originally, so I just copied it.
The counter was on food processing machines which operated in a refrigerated
and generally hostile environment that was subject to washing down by hose,
so the board had to be totally proof against condensation and 'wet' water.

Arfa

Meat Plow wrote:
On Thu, 06 Sep 2007 23:21:44 +0000, Arfa Daily wrote:

"Ron(UK)" wrote in message
...
Meat Plow wrote:
On Thu, 06 Sep 2007 17:13:14 +0100, Ron(UK) wrote:
I bet that happened because the white gluey stuff they put on to
stabilise the part had dried out and cracked off, same goes for the
smoothing caps. I usually stabilise them with a squirt of high temp hot
melt glue, the woodworking stuff. When it gets hot it goes softer, but
doesn't run off like the clear type does.
Seems to have been the cause of the failure IIRC. Have you used silicone
rubber? Seems like it would be a good choice.

Yes, silicone bath sealer works also . It just takes longer to set and
they might be a slight risk of corrosion from the acetic acid, tho having
said that, I`ve seen whole pcb`s potted in the stuff.

Ron(UK)
I used to pot a whole board that I used to make for a company, in a
'flowing' silicon rubber. It got in and around and under every component on
the board, and then cured just like bath sealer, but without the acetic acid
smell. It was designed for electronic potting, so I guess it was corrosion
proof.


Isn't 100% pure silicon just that? Or is silicon naturally acetic? Would
"corrosion proof" silicon have an additive?


Is it possible that the 'vinegar smell' is some kind of mould or fungus
inhibitor? I don't remember the original stuff we used to get from
RadioSpares having an acetic acid smell - but I could be mistaken, it
was a long time ago.

Ron(UK)

"Ron(UK)" wrote:

Meat Plow wrote:
Arfa Daily wrote:
"Ron(UK)" wrote
Meat Plow wrote:
Ron(UK) wrote:
I bet that happened because the white gluey stuff they put on to
stabilise the part had dried out and cracked off,

I understand that this may be PVA adhesive or something very similar.


same goes for the
smoothing caps. I usually stabilise them with a squirt of high temp hot
melt glue, the woodworking stuff. When it gets hot it goes softer, but
doesn't run off like the clear type does.
Seems to have been the cause of the failure IIRC. Have you used silicone
rubber? Seems like it would be a good choice.

Yes, silicone bath sealer works also . It just takes longer to set and
they might be a slight risk of corrosion from the acetic acid, tho having
said that, I`ve seen whole pcb`s potted in the stuff.

Ron(UK)
I used to pot a whole board that I used to make for a company, in a
'flowing' silicon rubber. It got in and around and under every component on
the board, and then cured just like bath sealer, but without the acetic acid
smell. It was designed for electronic potting, so I guess it was corrosion
proof.


Isn't 100% pure silicon just that? Or is silicon naturally acetic? Would
"corrosion proof" silicon have an additive?

Is it possible that the 'vinegar smell' is some kind of mould or fungus
inhibitor?

It is actually acetic acid AIUI. In the cheap 'bathroom' silicones it's what 'makes
it go off'. It's inadvisable to use this for electronics because of the acid fumes.

I don't remember the original stuff we used to get from
RadioSpares having an acetic acid smell - but I could be mistaken, it
was a long time ago.

Electronic grades use a different and more expensive activator.

I suspect the stuff Arfa's talking about is quite different. Does it set quite
hard ?

Graham

N Cook wrote:

N Cook wrote in message
...
msg wrote in message
...

graph paper is 1mm squares


Maybe in Eurpope. There are quite a few types of graph paper.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Meat Plow wrote:

Isn't 100% pure silicon just that? Or is silicon naturally acetic? Would
"corrosion proof" silicon have an additive?


100% pure Silicon is a metal, while Silicone has other uses. ;-)


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"Eeyore" wrote in message
...


"Ron(UK)" wrote:

Meat Plow wrote:
Arfa Daily wrote:
"Ron(UK)" wrote
Meat Plow wrote:
Ron(UK) wrote:
I bet that happened because the white gluey stuff they put on to
stabilise the part had dried out and cracked off,

I understand that this may be PVA adhesive or something very similar.


same goes for the
smoothing caps. I usually stabilise them with a squirt of high
temp hot
melt glue, the woodworking stuff. When it gets hot it goes softer,
but
doesn't run off like the clear type does.
Seems to have been the cause of the failure IIRC. Have you used
silicone
rubber? Seems like it would be a good choice.

Yes, silicone bath sealer works also . It just takes longer to set
and
they might be a slight risk of corrosion from the acetic acid, tho
having
said that, I`ve seen whole pcb`s potted in the stuff.

Ron(UK)
I used to pot a whole board that I used to make for a company, in a
'flowing' silicon rubber. It got in and around and under every
component on
the board, and then cured just like bath sealer, but without the
acetic acid
smell. It was designed for electronic potting, so I guess it was
corrosion
proof.


Isn't 100% pure silicon just that? Or is silicon naturally acetic?
Would
"corrosion proof" silicon have an additive?

Is it possible that the 'vinegar smell' is some kind of mould or fungus
inhibitor?

It is actually acetic acid AIUI. In the cheap 'bathroom' silicones it's
what 'makes
it go off'. It's inadvisable to use this for electronics because of the
acid fumes.

I don't remember the original stuff we used to get from
RadioSpares having an acetic acid smell - but I could be mistaken, it
was a long time ago.

Electronic grades use a different and more expensive activator.

I suspect the stuff Arfa's talking about is quite different. Does it set
quite
hard ?

Graham


No, as I said, it set flexible just like bathroom sealer. It was 'clear'
(cloudy) rather than white, and stuck to the surface of the board or the
components so strongly that it was almost impossible to ever get off. I
actually did manage to repair a couple of boards by first cutting through
the stuff with a scalpel, which was quite easy apart from the silicone
rubber 'drag' on the blade, and then painstakingly picking it away with
tweezers.

I've just looked it up. It was Dow Corning Silastic 734, I think, although
it does say that it does release acetic acid on contact with moisture in the
air, so I might be wrong remembering that it didn't. It's been a few years
ago now.

Arfa

Michael A. Terrell wrote:
Meat Plow wrote:
Isn't 100% pure silicon just that? Or is silicon naturally acetic? Would
"corrosion proof" silicon have an additive?


100% pure Silicon is a metal, while Silicone has other uses. ;-)



Silicon is listed as a nonmetallic element.
I thought I heard different so I looked it up.

In article ,
"Michael A. Terrell" wrote:

N Cook wrote:

N Cook wrote in message
...
msg wrote in message
...

graph paper is 1mm squares


Maybe in Eurpope. There are quite a few types of graph paper.

That was a *scale* reference to his previous posting, showing parts
photographed on graph paper.

Smitty Two wrote:

In article ,
"Michael A. Terrell" wrote:

N Cook wrote:

N Cook wrote in message
...
msg wrote in message
...

graph paper is 1mm squares


Maybe in Eurpope. There are quite a few types of graph paper.

That was a *scale* reference to his previous posting, showing parts
photographed on graph paper.


If so, it isn't obvious from the post I saw.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"Michael A. Terrell" wrote:

N Cook wrote:

graph paper is 1mm squares

Maybe in Eurpope.

In most of the world actually.

Graham

Eyesore wrote:

"Michael A. Terrell" wrote:

N Cook wrote:

graph paper is 1mm squares

Maybe in Eurpope.

In most of the world actually.

Graham

No, it isn't, you dumb ASS. There are all kinds of graph paper,
including logarithmic graphs. How about a Smith Chart? I suppose you
think that is a metric graph? The common linear types are rarely used,
these days. I have to special order it from a lot of office supply
places, but I can print a lot of technical graph paper from cheap
software, none that is metric.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"Michael A. Terrell" wrote:

Eyesore wrote:
"Michael A. Terrell" wrote:
N Cook wrote:

graph paper is 1mm squares

Maybe in Eurpope.

In most of the world actually.

Graham

No, it isn't, you dumb ASS. There are all kinds of graph paper,
including logarithmic graphs. How about a Smith Chart?

Both of these would obviously not be in linear increments so I'm surprised you
even mention them.

Do you really imagine I've never seen log graph paper ? N Cook didn't use it did
he ?


I suppose you think that is a metric graph? The common linear types are
rarely used,
these days. I have to special order it from a lot of office supply
places, but I can print a lot of technical graph paper from cheap
software, none that is metric.

My point is quite simply that anyone who assumes inches are the reference
dimension of choice these days is simply kidding themselves.

There are only 3 countries in the world today still using inches and 2 of them
don't even fit the description of being 'modern civilised nations'. It's could
be argued that the third example only marginally qualifies for that description
too.

Graham

Eeyore wrote:

"Michael A. Terrell" wrote:

Eyesore wrote:
"Michael A. Terrell" wrote:
N Cook wrote:

graph paper is 1mm squares

Maybe in Eurpope.

In most of the world actually.

Graham

No, it isn't, you dumb ASS. There are all kinds of graph paper,
including logarithmic graphs. How about a Smith Chart?

Both of these would obviously not be in linear increments so I'm surprised you
even mention them.


Why? You make a blanket statement about ALL graph paper, and ignore
that there is more than one type, because it doesn't fit into your line
of anti American bull****.


Do you really imagine I've never seen log graph paper ?


Sure you have, and I'm sure that you've used it when you're out of
toilet paper.


N Cook didn't use it did he?


He didn't say one way or the other, did he? That makes your point
moot, as usual, donkey boy.


I suppose you think that is a metric graph? The common linear types are
rarely used,
these days. I have to special order it from a lot of office supply
places, but I can print a lot of technical graph paper from cheap
software, none that is metric.

My point is quite simply that anyone who assumes inches are the reference
dimension of choice these days is simply kidding themselves.


No, it is another of your usual anti American bull**** posts.


There are only 3 countries in the world today still using inches and 2 of them
don't even fit the description of being 'modern civilised nations'. It's could
be argued that the third example only marginally qualifies for that description
too.


You only "marginally qualify" as having a mind. Why are you trolling
the repair newsgroup? Aren't you getting enough abuse of the other
electronics newsgroups?



--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"Michael A. Terrell" wrote:

Eeyore wrote:

My point is quite simply that anyone who assumes inches are the reference
dimension of choice these days is simply kidding themselves.

No, it is another of your usual anti American bull**** posts.

It's a fact.

Get over it.

Graham

In article ,
"Michael A. Terrell" wrote:

Smitty Two wrote:

In article ,
"Michael A. Terrell" wrote:

N Cook wrote:

N Cook wrote in message
...
msg wrote in message
...

graph paper is 1mm squares


Maybe in Eurpope. There are quite a few types of graph paper.

That was a *scale* reference to his previous posting, showing parts
photographed on graph paper.


If so, it isn't obvious from the post I saw.

That's why I made the comment, to clue you in. Sometimes it helps to
read all the postings in a given thread, even from those with whom you
have a personality conflict. Gives a more complete picture. In this
case, it would have saved you from a stupid national pride contest.

Smitty Two wrote:

In article ,
"Michael A. Terrell" wrote:

Smitty Two wrote:

In article ,
"Michael A. Terrell" wrote:

N Cook wrote:

N Cook wrote in message
...
msg wrote in message
...

graph paper is 1mm squares


Maybe in Eurpope. There are quite a few types of graph paper.

That was a *scale* reference to his previous posting, showing parts
photographed on graph paper.


If so, it isn't obvious from the post I saw.

That's why I made the comment, to clue you in. Sometimes it helps to
read all the postings in a given thread, even from those with whom you
have a personality conflict. Gives a more complete picture. In this
case, it would have saved you from a stupid national pride contest.


Its Eeyore who has the problem. Everything American is bad, according
to the demented donkey.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Eeyore wrote:

"Michael A. Terrell" wrote:

Eeyore wrote:

My point is quite simply that anyone who assumes inches are the reference
dimension of choice these days is simply kidding themselves.

No, it is another of your usual anti American bull**** posts.

It's a fact.

Get over it.

Graham


Yawn. Get over yourself.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida