Homebrew PCBs

UK'ers, anyone in uk _not_ using fecl for etching?

If not what are you using, and where did you get it.



-- 

Lez

Hi Lez

 

Although im not an UK'er i thought I would answer anyway.

I use a combination of sulphuric acid and hydrogen peroxide. Basically the mixture is one part each in five parts water. This stuff works great but.. You need to be careful, have great ventilation and you would need some kind of respiratory protection since this stuff produces chloridic gasses. Other than that you can have your boards etched in a matter of minutes.

 

Oh. One more thing. It will only work for about ten or fifteen minutes.

  ----- Original Message ----- 
  From: Lez 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Friday, January 26, 2007 12:35 PM
  Subject: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?


  UK'ers, anyone in uk _not_ using fecl for etching?

  If not what are you using, and where did you get it.

  -- 

  Lez


   

[Non-text portions of this message have been removed]

----- Original Message ----- 

From: "Lez" <lez.briddon@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, January 26, 2007 11:35 AM
Subject: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?


> UK'ers, anyone in uk _not_ using fecl for etching?
>
> If not what are you using, and where did you get it.

I normally use FeCl3 but I've tried HCl and H2O2. It works OK and it's quite 
easy to find the materials - a chemist for the H2O2 and a hardware store for 
the HCl.

Leon
--
Leon Heller
Amateur radio call-sign G1HSM
Yaesu FT-817ND transceiver
Suzuki SV1000S motorcycle
leon355@...
http://www.geocities.com/leon_heller

On Sat, 27 Jan 2007 08:05:20 +0100, Stig Ankj\ufffdr Pedersen <sap@...>  
wrote:

>
> Although im not an UK'er i thought I would answer anyway.
> I use a combination of sulphuric acid and hydrogen peroxide. Basically  
> the mixture is one part each in five parts water. This stuff works great  
> but.. You need to be careful, have great ventilation and you would need  
> some kind of respiratory protection since this stuff produces chloridic  
> gasses. Other than that you can have your boards etched in a matter of  
> minutes.
> Oh. One more thing. It will only work for about ten or fifteen minutes.


Please, if it produces chlorine gas you are using hydrochloric acid, not  
sulphuric acid. Also, if it produces those fumes you are probably using  
much too high concentrations.


I shudder to think what people are doing without knowing what they are  
doing.

Recently i read on the web that car batteries use hydrochloric acid..  
scary...

ST

On 27/01/07, Leon <leon355@...> wrote:
>
>
>
>
>
>
> ----- Original Message -----
>  From: "Lez" <lez.briddon@...>
>  To: <Homebrew_PCBs@yahoogroups.com>
>
>  Sent: Friday, January 26, 2007 11:35 AM
>  Subject: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?
>
>  > UK'ers, anyone in uk _not_ using fecl for etching?
>  >
>  > If not what are you using, and where did you get it.
>
>  I normally use FeCl3 but I've tried HCl and H2O2. It works OK and it's quite
>  easy to find the materials - a chemist for the H2O2 and a hardware store for
>  the HCl.
>
>  Leon

Leon thanks, ok right then, what do use as a hardware store, I have
sainsburys homebase and b&q, but I can guess before I take a trip
their if I write HCI on a scrap of paper, hand it to customer services
and say where do you keep this, I will get a very blank stare.........

Just what do you buy it as?



Lez

>  I normally use FeCl3 but I've tried HCl and H2O2. It works OK and it's quite
>  easy to find the materials - a chemist for the H2O2 and a hardware store for
>  the HCl.
>
>  Leon

Leon thanks, ok right then, what do use as a hardware store, I have
sainsburys homebase and b&q, but I can guess before I take a trip
their if I write HCI on a scrap of paper, hand it to customer services
and say where do you keep this, I will get a very blank stare.........

Just what do you buy it as?

HCL is Hydrochloric Acid isn't it? In which case it is used as concrete cleaner and available in the building section of B & Q.


[Non-text portions of this message have been removed]

>
>  Just what do you buy it as?
>
>  HCL is Hydrochloric Acid isn't it? In which case it is used as concrete cleaner and available in the building section of B & Q.

Ok I'll take a trip to them, any brand better than the other, or just
their own branded stuff?

I have used their driveway cleaner before, my neighbor came out
complaining about the smell, I was stood in the middle of a 10ft
diameter well wet area and could not smell a thing, I thought he was
'in need of medication' till the wife came out and complained too, I
guess I just could not smell the stuff, rotten eggs I think he said,
does that sound familiar?



Lez

----- Original Message ----- 

From: "Lez" <lez.briddon@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, January 27, 2007 2:07 PM
Subject: Re: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?


> On 27/01/07, Leon <leon355@...> wrote:
>>
>>
>>
>>
>>
>>
>> ----- Original Message -----
>>  From: "Lez" <lez.briddon@...>
>>  To: <Homebrew_PCBs@yahoogroups.com>
>>
>>  Sent: Friday, January 26, 2007 11:35 AM
>>  Subject: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?
>>
>>  > UK'ers, anyone in uk _not_ using fecl for etching?
>>  >
>>  > If not what are you using, and where did you get it.
>>
>>  I normally use FeCl3 but I've tried HCl and H2O2. It works OK and it's 
>> quite
>>  easy to find the materials - a chemist for the H2O2 and a hardware store 
>> for
>>  the HCl.
>>
>>  Leon
>
> Leon thanks, ok right then, what do use as a hardware store, I have
> sainsburys homebase and b&q, but I can guess before I take a trip
> their if I write HCI on a scrap of paper, hand it to customer services
> and say where do you keep this, I will get a very blank stare.........
>
> Just what do you buy it as?

It's usually called Spirits of Salts and is 30% HCl. Builders merchants are 
best as it is used for cleaning brickwork and clearing drains.

Leon

> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com
> [mailto:Homebrew_PCBs@yahoogroups.com]On Behalf Of Lez
> Sent: Saturday, January 27, 2007 11:05 AM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?
>
>
> I have used their driveway cleaner before, my neighbor came out
> complaining about the smell, I was stood in the middle of a 10ft
> diameter well wet area and could not smell a thing, I thought he was
> 'in need of medication' till the wife came out and complained too, I
> guess I just could not smell the stuff, rotten eggs I think he said,
> does that sound familiar?
>
>
>
> Lez
>

That sounds like it must have been Sulfuric Acid-based (H2SO4), and you
somehow generated Hydrogen Sulfide (H2S) - which gives off the "rotten-egg"
smell

And that is _NOT_ the acid you want....

Randy

AND; There is a world of difference between spreading the stuff
(whatever it was) over many square feet (or meters) on a driveway
and using less than a half-liter (a pint or so) in a glass tray to
etch a circuit board.

Like, its a matter of proportion.

Pardon my sarcasm.

Roland F. Harriston
*****************************


Randy Ledyard wrote:

>
> > -----Original Message-----
> > From: Homebrew_PCBs@yahoogroups.com 
> <mailto:Homebrew_PCBs%40yahoogroups.com>
> > [mailto:Homebrew_PCBs@yahoogroups.com 
> <mailto:Homebrew_PCBs%40yahoogroups.com>]On Behalf Of Lez
> > Sent: Saturday, January 27, 2007 11:05 AM
> > To: Homebrew_PCBs@yahoogroups.com 
> <mailto:Homebrew_PCBs%40yahoogroups.com>
> > Subject: Re: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?
> >
> >
> > I have used their driveway cleaner before, my neighbor came out
> > complaining about the smell, I was stood in the middle of a 10ft
> > diameter well wet area and could not smell a thing, I thought he was
> > 'in need of medication' till the wife came out and complained too, I
> > guess I just could not smell the stuff, rotten eggs I think he said,
> > does that sound familiar?
> >
> >
> >
> > Lez
> >
>
> That sounds like it must have been Sulfuric Acid-based (H2SO4), and you
> somehow generated Hydrogen Sulfide (H2S) - which gives off the 
> "rotten-egg"
> smell
>
> And that is _NOT_ the acid you want....
>
> Randy
>
>

>
>  That sounds like it must have been Sulfuric Acid-based (H2SO4), and you
>  somehow generated Hydrogen Sulfide (H2S) - which gives off the "rotten-egg"
>  smell
>
>  And that is _NOT_ the acid you want....
>
>  Randy

Ok 1 product down............

Is H2S dangerous, think I heard it mentioned about cats on cars

Lez

----- Original Message ----- 

From: "Lez" <lez.briddon@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, January 27, 2007 9:04 PM
Subject: Re: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?


> >
>>  That sounds like it must have been Sulfuric Acid-based (H2SO4), and you
>>  somehow generated Hydrogen Sulfide (H2S) - which gives off the 
>> "rotten-egg"
>>  smell
>>
>>  And that is _NOT_ the acid you want....
>>
>>  Randy
>
> Ok 1 product down............
>
> Is H2S dangerous, think I heard it mentioned about cats on cars

H2S is somewhat toxic.

Leon

On Sat, 27 Jan 2007 22:04:47 +0100, Lez <lez.briddon@...> wrote:

>
> Ok 1 product down............
> Is H2S dangerous, think I heard it mentioned about cats on cars
> Lez


It is by no means certain sulphuric acid is really what was in that  
cleaner. Check ingredients list. For PCB work it would be preferred to get  
"pure" chemicals without any added substances (other than water). You do  
not know what any other ingredients may do to the resist or how they may  
react with H2O2. For example i think it is not a good idea to combine H2O2  
with some bleaches, which could easily be in some cleaners.

ST

> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com
> [mailto:Homebrew_PCBs@yahoogroups.com]On Behalf Of Lez
> Sent: Saturday, January 27, 2007 4:05 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?
>
>
> >
> >  That sounds like it must have been Sulfuric Acid-based (H2SO4), and you
> >  somehow generated Hydrogen Sulfide (H2S) - which gives off the
> "rotten-egg"
> >  smell
> >
> >  And that is _NOT_ the acid you want....
> >
> >  Randy
>
> Ok 1 product down............
>
> Is H2S dangerous, think I heard it mentioned about cats on cars
>
> Lez

Lez
Lets just say sticking a match into a container of it while holding it close
to your face amy not help your appearance.....

from Wikipedia:
"Hydrogen sulfide is a highly toxic and flammable gas. Because it is heavier
than air it tends to accumulate at the bottom of poorly ventilated spaces.
Although very pungent at first, it quickly deadens the sense of smell, so
potential victims may be unaware of its presence until it is too late. For
more information see an MSDS."

Stefan - Wikipedia also says
"Hydrogen sulfide used to have importance in analytical chemistry for well
over a century, in the qualitative inorganic analysis of metal ions. For
such small-scale laboratory use, H2S was made as needed in a Kipp generator
by reaction of sulfuric acid (H2SO4) with ferrous sulfide FeS."

I can't see producing H2S from NaOH (lye), which might be another driveway
cleaner product ingredient, and I can't see producing it from just a
detergent-based product....

On Sat, 27 Jan 2007 23:02:26 +0100, Randy Ledyard <rll_groups@...>  
wrote:

>
> I can't see producing H2S from NaOH (lye), which might be another  
> driveway
> cleaner product ingredient, and I can't see producing it from just a
> detergent-based product....


Who says H2S was involved at all? Just because the neighbour said it  
smelled of rotten eggs doesn't make it H2S. I think it unlikely that the  
cleaner contained sulphuric acid.


ST

Randy
  How long is the sense of smell deadened?  Hydrogen sulfide in the last
thing I can remember smelling - in 1963.  I was tested years ago and seem to
have very limited to no sense of smell all these years.

John


On 1/27/07, Randy Ledyard <rll_groups@...> wrote:
>
>
> from Wikipedia:
> "Hydrogen sulfide is a highly toxic and flammable gas. Because it is
> heavier
> than air it tends to accumulate at the bottom of poorly ventilated spaces.
> Although very pungent at first, it quickly deadens the sense of smell, so
> potential victims may be unaware of its presence until it is too late. For
> more information see an MSDS."
>

-- 
John D Young
WA8KNE
ETC USN retired


[Non-text portions of this message have been removed]

When I poured it on the ground, it turned bubbly-white, if thats any help.



But thats all beside the point, what stores in the uk are people buying
their non-fecl etchants from and specifically which products!

IF any!


[Non-text portions of this message have been removed]

I think the loss of smell is a temporary thing when exposed to a large
amount, the reason that was one of the last things you smelled is because
the nose is sooo sensitive to that particular family of compounds.

Randy

> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com
> [mailto:Homebrew_PCBs@yahoogroups.com]On Behalf Of John Young
> Sent: Saturday, January 27, 2007 5:51 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?
>
>
> Randy
>   How long is the sense of smell deadened?  Hydrogen sulfide in the last
> thing I can remember smelling - in 1963.  I was tested years ago
> and seem to
> have very limited to no sense of smell all these years.
>
> John
>
>
> On 1/27/07, Randy Ledyard <rll_groups@...> wrote:
> >
> >
> > from Wikipedia:
> > "Hydrogen sulfide is a highly toxic and flammable gas. Because it is
> > heavier
> > than air it tends to accumulate at the bottom of poorly
> ventilated spaces.
> > Although very pungent at first, it quickly deadens the sense of
> smell, so
> > potential victims may be unaware of its presence until it is
> too late. For
> > more information see an MSDS."
> >
>
> --
> John D Young
> WA8KNE
> ETC USN retired
>

> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com
> [mailto:Homebrew_PCBs@yahoogroups.com]On Behalf Of Stefan Trethan
> Sent: Saturday, January 27, 2007 5:47 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?
>
>
> On Sat, 27 Jan 2007 23:02:26 +0100, Randy Ledyard
> <rll_groups@...>
> wrote:
>
> >
> > I can't see producing H2S from NaOH (lye), which might be another
> > driveway
> > cleaner product ingredient, and I can't see producing it from just a
> > detergent-based product....
>
>
> Who says H2S was involved at all? Just because the neighbour said it
> smelled of rotten eggs doesn't make it H2S. I think it unlikely that the
> cleaner contained sulphuric acid.
>
>
> ST
>

How many other compounds are there out there that smell like rotten eggs?
Thiols/Mercaptans/Sulfides are the only ones I know of...

On Sun, 28 Jan 2007 09:01:40 +0100, Randy Ledyard <rll_groups@...>  
wrote:

>
> How many other compounds are there out there that smell like rotten eggs?
> Thiols/Mercaptans/Sulfides are the only ones I know of...


If a comment from a neighbour would suffice to identify chemicals that  
would make for a cheap analyzer ;-)

ST

----- Original Message ----- 

From: "John Young" <wa8kne@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, January 27, 2007 10:50 PM
Subject: Re: [Homebrew_PCBs] UK'ers, anyone in uk _not_ using fecl ?


> Randy
>  How long is the sense of smell deadened?  Hydrogen sulfide in the last
> thing I can remember smelling - in 1963.  I was tested years ago and seem 
> to
> have very limited to no sense of smell all these years.

It should only be temporary.

Leon
--
Leon Heller
Amateur radio call-sign G1HSM
Yaesu FT-817ND transceiver
Suzuki SV1000S motorcycle
leon355@...
http://www.geocities.com/leon_heller

But thats all drifting off topic isn't it, how it smells is irrelevant when
its the wrong stuff.........

The search behind the topic was...

If I walk into XYZ uk-store, which product does one buy, and so far, no one,
can name a store that sells an item that i susable, its all generic answers,
drain cleaner, brick cleaner, so you wont be guaranteed to get the right
stuff.

Whats needed is a simple ''XYZ store sells ABC product, it says SKU#99999 on
the side of it, thats what you want''

Seems everyone in the UK buys fecl from maplins........


[Non-text portions of this message have been removed]

At 6:07 am ((PST)) Sat Jan 27, 2007, Lez wrote:
>On 27/01/07, Leon <leon355@...> wrote:
> >  I normally use FeCl3 but I've tried HCl and H2O2. It works OK and it's 
> quite
> >  easy to find the materials - a chemist for the H2O2 and a hardware 
> store for
> >  the HCl.
>
>Leon thanks, ok right then, what do use as a hardware store, I have
>sainsburys homebase and b&q, but I can guess before I take a trip
>their if I write HCI on a scrap of paper, hand it to customer services
>and say where do you keep this, I will get a very blank stare.........
>
>Just what do you buy it as?

We've just been through the five million names for hydrochloric acid
and some alternative suppliers: were you away for that lesson? :-(


Regards, LenW

At 9:59 am ((PST)) Sat Jan 27, 2007, Randy Ledyard wrote:
> > [mailto:Homebrew_PCBs@yahoogroups.com]On Behalf Of Lez
> > I have used their driveway cleaner before, my neighbor came out
> > complaining about the smell, I was stood in the middle of a 10ft
> > diameter well wet area and could not smell a thing, I thought he was
> > 'in need of medication' till the wife came out and complained too, I
> > guess I just could not smell the stuff, rotten eggs I think he said,
> > does that sound familiar?

Rotten eggs = hydrogen sulphide, common as a laboratory reagent
and dangerous because it's toxic and it anaesthetizes the sense of
smell - so those most at risk don't realize they are being poisoned.

>That sounds like it must have been Sulfuric Acid-based (H2SO4), and you
>somehow generated Hydrogen Sulfide (H2S) - which gives off the "rotten-egg"
>smell

H2S was probably liberated by the acid from some rotted organic
residues , possibly in a drain - it doesn't prove what the acid was.
(BTW, not hazardous unless you stick your head down the drain.)

>And that is _NOT_ the acid you want....

Not what Lez was asking for, but it would do the job, as would
battery top-up acid if it were cheaply available.

Also sulphamic acid - a beige crystalline powder like light brown
sugar, often sold for kettle descaling, with an activity similar to
sulphuric acid and the convenience of a non-hygroscopic powder.
However, branded retail packaging makes that uneconomic.


Regards, LenW

At 2:21 pm ((PST)) Sat Jan 27, 2007, Randy Ledyard wrote:
>Stefan - Wikipedia also says [snip] For
>such small-scale laboratory use, H2S was made as needed in a Kipp generator
>by reaction of sulfuric acid (H2SO4) with ferrous sulfide FeS."

In producing analytical reagent H2S one would choose H2SO4 over
HCl because HCl is so volatile and would contaminate the product.

AFAIK, any serious laboratory uses H2S from a gas cylinder
(it liquefies easily under pressure) - hence the danger from a
leak, as there is a large amount available if it goes undetected.

>I can't see producing H2S from NaOH (lye), which might be another
>driveway cleaner product ingredient, and I can't see producing it from
>just a detergent-based product....

You gave the clue above: an acid + a sulphide, in this case
very likely an organic sulphide produced from rotting matter.
That's one of the reasons drains smell bad.

BTW, since it's been mentioned: Sodium Hydroxide (NaOH) is
shelf stock at Focus DIY (UK DIY chain), poly-bottles, 500g &
1Kg, rattle like a granular powder.

Perhaps we should build a directory of alternative chemical
suppliers - but let's leave the homeopathy clinic out, OK? ;-)


Regards, LenW

At 1:34 am ((PST)), Sun Jan 28, 2007 Lez wrote:

>But thats all drifting off topic isn't it, how it smells is irrelevant when
>its the wrong stuff.........

Safety requirements make it pretty likely that either
the small print on the label, or an MSDS, will disclose
the major constituents. OTOH it's unlikely that any
additive in a cheap acid cleaner will inhibit its etching
action - though I suppose it's just possible there might
be some other subtle side effect.

[There was a drain cleaner with an organic solvent but:
a) it wasn't acidic in nature;
b) it was withdrawn from the market because
  1. it tended to dissolve plastic waste pipes, and
  2. it polluted waste water.]

>The search behind the topic was...
>
>If I walk into XYZ uk-store, which product does one buy, and so far, no one,
>can name a store that sells an item that i susable, its all generic answers,
>drain cleaner, brick cleaner, so you wont be guaranteed to get the right
>stuff.

Perhaps because everything except the name of the store
had already been answered before you asked.

>Whats needed is a simple ''XYZ store sells ABC product,
>it says SKU#99999 on the side of it, thats what you want''
>
>Seems everyone in the UK buys fecl from maplins........

If they want to use such a crap etchant,
I can't think of a more appropriate supplier ;-)

...and it serves them right if they are too ignorant to
acidulate with extra HCl - may they drown in slime :-)

However, to answer the question...

Meera Pharmacy, 4 Beech Road,
St Albans (01727) 851132,
ask for Dina - say Len sent you.

Other details already given in message 17491
on Jan 21, 2007 in thread: H2O2 in the UK.
[ Where "someone" = "Lez Briddon" ]

HTH - was that specific enough for you?

I have bought 9% (30vol) H2O2 from a pharmacy in
Bedford - sorry, its name forgotten - and, in the very
distant past, 500ml bottles of 3% (10vol) from Boots.

[My previous bottle of HCl, IIRC as 'Spirits of Salts", was
from hardware store Dearman Gomms, in St Albans.]

Now, if my local pharmacist can get these things,
then any independent pharmacist ought to be able to.

I don't know if that applies to supermarket pharmacies too:
it seems to me they _should_ be able to but I suspect
there is less chance of finding shelf stock and more that
they CBA or are PC-crippled. [I noticed a news item about
a supermarket refusing to sell an alcoholic beverage to an
aged ex-mayor of York without proof he was over 18;
the management defended their staff training. :-)) ]

It may be that you stand more chance of getting chemical
supplies at a pharmacy where you are well known. For
example, the one that supplies your medication - unless
that in itself disqualifies you ;-)


Regards, LenW

At 12:33 am ((PST)) Sun Jan 28, 2007, Stefan Trethan wrote:

>On Sun, 28 Jan 2007 09:01:40 +0100, Randy Ledyard wrote:
> > How many other compounds are there out there that smell like rotten eggs?
> > Thiols/Mercaptans/Sulfides are the only ones I know of...
>
>If a comment from a neighbour would suffice to identify chemicals
>that would make for a cheap analyzer ;-)

Some groups of chemicals are easily identified by smell, for example,
ketones or esters. Most common plastics can be identified by
cautiously sniffing their combustion products. It is a commonplace
to choose between various palatable or tainted foodstuffs by
agreeable or disagreeable smells. The nose can be a quite
discriminating analytical instrument.

Sulphurous compounds can be uniquely recognizable and
disagreeable, especially, but not limited to, those that are
produced by rotting meat (and in my unfortunate experience,
rotting onions).

You may be relying on your or your neighbour's ability to detect
ethanethiol at a concentration as low as one part in 2.8 billion
to protect you from an explosion from a natural gas leak: see
http://en.wikipedia.org/wiki/New_London_School_explosion

[If you've been at the ammonia bottle again, you're excused ;-) ]

On Sun, 28 Jan 2007 20:12:50 +0100, Len Warner <novost@...> wrote:

>
> Some groups of chemicals are easily identified by smell, for example,
> ketones or esters. Most common plastics can be identified by
> cautiously sniffing their combustion products. It is a commonplace
> to choose between various palatable or tainted foodstuffs by
> agreeable or disagreeable smells. The nose can be a quite
> discriminating analytical instrument.
> Sulphurous compounds can be uniquely recognizable and
> disagreeable, especially, but not limited to, those that are
> produced by rotting meat (and in my unfortunate experience,
> rotting onions).
> You may be relying on your or your neighbour's ability to detect
> ethanethiol at a concentration as low as one part in 2.8 billion
> to protect you from an explosion from a natural gas leak: see
> http://en.wikipedia.org/wiki/New_London_School_explosion
> [If you've been at the ammonia bottle again, you're excused ;-) ]


Unless the cleaner in question is found and the ingredient list evaluated  
you will just have to live with my refusing to believe in any sulphuric  
acid in it.

ST

>  I don't know if that applies to supermarket pharmacies too:
>  it seems to me they _should_ be able to but I suspect
>  there is less chance of finding shelf stock and more that
>  they CBA or are PC-crippled. [I noticed a news item about
>  a supermarket refusing to sell an alcoholic beverage to an
>  aged ex-mayor of York without proof he was over 18;
>  the management defended their staff training. :-)) ]

Yes I shop in that very supermarket, and I live around the road from
the (now tv famous) local store who refused to serve the mother of a
2yr old as the child was wearing a hooded top, and is now no doubt
barred from the store.

My house backs onto a house where a police van was set on fire by
squirting petrol into the front grill and igniting it, I'm amazed it
worked on a water filled radiator on a diesel van but their you go
(pictures www.yorkshirescapital.co.uk)

Its such a nice place you need permission from both grandparents to
buy matches these days

Lez