Anyone have a better knowledge of why fatty acids appear in circumstances
where high dielectric strength/ good insulation is needed. Hence the "fishy
smell" of physically broken/leaking electrolytic capacitors.
Possible candidates ( from Googling ie no specialised knowledge on this )
eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and degradation
product 2,4-heptadienal/2,4-hepadienal ?
, PETEP oil (Penta- Etythrite-Tetra Fatty Acid Polyester oil)

And in the case of rotted horse manure smell from some types of old
transformer windings perhaps Caproic Acid or Hexanoic acid giving that smell

N_Cook wrote:

[...]
And in the case of rotted horse manure smell from some types of old
transformer windings perhaps Caproic Acid or Hexanoic acid giving that smell

Some pre war Philips radio sets had rubber-covered wiring that stank
like rotted manure when you touched it with a soldering iron. I have no
idea what they used in it that was different from other makes.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On Wed, 31 Mar 2010 06:32:20 -0400 Meat Plow wrote in Message id:
:

On Wed, 31 Mar 2010 10:06:47 +0100, "N_Cook" wrote:

Anyone have a better knowledge of why fatty acids appear in circumstances
where high dielectric strength/ good insulation is needed. Hence the "fishy
smell" of physically broken/leaking electrolytic capacitors.
Possible candidates ( from Googling ie no specialised knowledge on this )
eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and degradation
product 2,4-heptadienal/2,4-hepadienal ?
, PETEP oil (Penta- Etythrite-Tetra Fatty Acid Polyester oil)

And in the case of rotted horse manure smell from some types of old
transformer windings perhaps Caproic Acid or Hexanoic acid giving that smell


Your interpretations of smells can be substantially different than
say, mine. When I smell the magic smoke, I don't think of farm animals
or a tuna boat, I think of #1 not smelling it at all because it's full
of caustic chemicals.

I don't think he's talking about smoke as much as he's referring to the
distinct smell of leaking electrolytics. I've got a section of test
equipment parts-mules (probably 150 different pieces or so. The smell down
that aisle is quite distinct! I'd say that "fishy" is as good a term as I
can think of.

Adrian Tuddenham wrote in message
nvalid.invalid...
N_Cook wrote:

[...]
And in the case of rotted horse manure smell from some types of old
transformer windings perhaps Caproic Acid or Hexanoic acid giving that
smell

Some pre war Philips radio sets had rubber-covered wiring that stank
like rotted manure when you touched it with a soldering iron. I have no
idea what they used in it that was different from other makes.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

So a different smell to overheating usual rubber smell?

I don't remember smelling that elecrolyte fishy smell for any 70s or earlier
caps. Someone must have decided in the 80s there was a useful way of getting
rid of abattoir or fish processors fatty waste as a bulking agent and
dielectric breakdown properties or something in caps. Similar reason for use
in some magnet wire lacquer it would seem

Adrian Tuddenham wrote in message
nvalid.invalid...
N_Cook wrote:

[...]
And in the case of rotted horse manure smell from some types of old
transformer windings perhaps Caproic Acid or Hexanoic acid giving that
smell

Some pre war Philips radio sets had rubber-covered wiring that stank
like rotted manure when you touched it with a soldering iron. I have no
idea what they used in it that was different from other makes.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk


Any idea what the distinctive (neutral, not pleasant not unpleasant) smell
is of ex-services electronic equipment is (UK anyway). If you go down the
lines of a radio rally/ hamfest the pitch of the guys specialising in
selling military surplus is quite distinctive. Military tropicalisation ?
anti-fungal spray ? mothballing agent ?

N_Cook wrote:

Adrian Tuddenham wrote in message
nvalid.invalid...
N_Cook wrote:

[...]
And in the case of rotted horse manure smell from some types of old
transformer windings perhaps Caproic Acid or Hexanoic acid giving that
smell

Some pre war Philips radio sets had rubber-covered wiring that stank
like rotted manure when you touched it with a soldering iron. I have no
idea what they used in it that was different from other makes.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

So a different smell to overheating usual rubber smell?

Yes, quite distinctly different.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

N_Cook wrote:

Adrian Tuddenham wrote in message
nvalid.invalid...
N_Cook wrote:

[...]
And in the case of rotted horse manure smell from some types of old
transformer windings perhaps Caproic Acid or Hexanoic acid giving that
smell

Some pre war Philips radio sets had rubber-covered wiring that stank
like rotted manure when you touched it with a soldering iron. I have no
idea what they used in it that was different from other makes.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk


Any idea what the distinctive (neutral, not pleasant not unpleasant) smell
is of ex-services electronic equipment is (UK anyway). If you go down the
lines of a radio rally/ hamfest the pitch of the guys specialising in
selling military surplus is quite distinctive. Military tropicalisation ?
anti-fungal spray ? mothballing agent ?

There are two smells I associate with that sort of thing. One is
Chatterton's Compound, a sort of tar used to fill cable jointing boxes,
it was more common in government surplus stores.

The other comes from a shellac-based varnish that was used to
tropicalise paxolin tagboards, but I don't know the cause of that smell
because shellac is supposed to be odourless. It isn't a fungicide
additive because I have smelled it when opening up some equipment I
built myself a long time ago. I had tropicalised it with a varnish
which I made by dissolving shellac flakes in alcohol, there were no
other ingredients.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On Mar 31, 3:32*am, Meat Plow wrote:
On Wed, 31 Mar 2010 10:06:47 +0100, "N_Cook" wrote:

Anyone have a better knowledge of why fatty acids appear in circumstances
where high dielectric strength/ good insulation is needed. Hence the "fishy
smell" of physically broken/leaking electrolytic capacitors.
Possible candidates ( from Googling ie no specialised knowledge on this )
eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and degradation
product 2,4-heptadienal/2,4-hepadienal ?
, PETEP oil (Penta- Etythrite-Tetra Fatty Acid Polyester oil)

And in the case of rotted horse manure smell from some types of old
transformer windings perhaps Caproic Acid or Hexanoic acid giving that smell

Your interpretations of smells can be substantially different than
say, mine. When I smell the magic smoke, I don't think of farm animals
or a tuna boat, I think of #1 not smelling it at all because it's full
of caustic chemicals.

Apparently you haven't replaced capacitors with the 'fishy' smell. It
most definitely is NOT the smoke coming out and it REALLY REALLY
smells like fish -- BAD fish and a LOT of it -- and just from a 6 mm
diameter 11 mm tall cap. Worse yet, when one cap is bad there are
usually many more (often all) to replace so the shop will stink for an
hour or two.

G²

Adrian Tuddenham wrote in message
nvalid.invalid...
N_Cook wrote:

Adrian Tuddenham wrote in message
nvalid.invalid...
N_Cook wrote:

[...]
And in the case of rotted horse manure smell from some types of old
transformer windings perhaps Caproic Acid or Hexanoic acid giving
that
smell

Some pre war Philips radio sets had rubber-covered wiring that stank
like rotted manure when you touched it with a soldering iron. I have
no
idea what they used in it that was different from other makes.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk


Any idea what the distinctive (neutral, not pleasant not unpleasant)
smell
is of ex-services electronic equipment is (UK anyway). If you go down
the
lines of a radio rally/ hamfest the pitch of the guys specialising in
selling military surplus is quite distinctive. Military tropicalisation
?
anti-fungal spray ? mothballing agent ?

There are two smells I associate with that sort of thing. One is
Chatterton's Compound, a sort of tar used to fill cable jointing boxes,
it was more common in government surplus stores.

The other comes from a shellac-based varnish that was used to
tropicalise paxolin tagboards, but I don't know the cause of that smell
because shellac is supposed to be odourless. It isn't a fungicide
additive because I have smelled it when opening up some equipment I
built myself a long time ago. I had tropicalised it with a varnish
which I made by dissolving shellac flakes in alcohol, there were no
other ingredients.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk


I was wondering if it was treatment to webbing associated with a lot of that
sort of stuff rather than the electronics as such.