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Liver of sulphur


#1

G’day Lars Dahlberg - you wrote:-

…“I work only in sterling so I tried to figure what you meant
with liver of sulphur”…

The correct or chemical name for “liver of sulfer” is potassium
sulphide. It is a solid which absorbs moisture easily so must be
kept in a tightly closed vessel. It also smells very strongly of
rotten eggs, so you wouldn’t be popular if you used it in the
house. You could ask your local pharmacy shop for it; they
would probably have to order it for you. To use, dissolve a
piece about the size of a pea in about 25 to 50mls of warm
water, put in your carefully cleaned silver and warm it gently.
Leave for a few minutes, then wash thoroughly; the whole item
will have turned black, but a few minutes light polishing will
brighten the high places in your work and leave the black in the
lower spots. The black is a very thin coat of silver sulphide.
If you put the blackened work into pickle the black will dissolve
and disappear. Personally I don’t like it, as with every day use
of silver jewellery the blackening will wear off in about six
months. Hope this helps. Cheers,

    /\
   / /    John Burgess, 
  / /
 / //\    @John_Burgess2
/ / \ \

/ (___)
(_________)


#2

Good day to you too. Best source of sulphur for blackening silver
and copper etc I find is the stuff they sell in liquid form at
plant shops or nurseries that they spray onto fruit trees to
combat lichen etc. Potassium polysulphide. $3 a bottle. Stays
good for weeks and months. No messing around with disolving
solid blocks, which goes off I believe quite a lot sooner.

Brian
Brian Adam ph/fx +64 9 817 6816 NEW ZEALAND
http://crash.ihug.co.nz/~adam/
http://www.optisearch.com


#3

Can I add something here?

If you add a drop or two of ammonia to the solution and then add
the piece to already heated liver of sulpher solution, you will
see that it changes colors until it gets to black. If you take
out, rinse off and burnish with a brass brush (a soft one) along
the way, you can (a ) stop at any of the different colors and (b)
you will find that brushing regularly will help keep the color
you select longer, altho it will come off eventually.

You can also keep the solution cold, but heat the piece (such as
with very hot water) and the color changes will happen
differently - sometimes getting more than one color on the piece
at the same time.

I find that the colors have an irridescent quality to them and
that waxing lightly will also keep the color a little longer.

Laura


#4
Potassium polysulphide. $3 a bottle. Stays good for weeks and
months. No messing around with disolving solid blocks, which
goes off I believe quite a lot sooner.

Cool Tip Brian.

Charles

Brain Press
Box 1624, Ste M, Calgary, Alberta, T2P 2L7, Canada
Tel: 403-263-3955 Fax: 403-283-9053 Email: @Charles_Lewton-Brain

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#5

G’day; there seems to be a small thread on the subject, (liver
of sulphur; potassium polysuphide) lately so I’ll jump in. This
substance, used extensively for blackening silver, is
commercially prepared by dissolving hydrogen sulphide (H2S) gas
in an alkali - sodium, potassium, calcium or ammonium hydroxides.
The gas itself smells of rotten eggs and is very poisonous - just
as poisonous as the cyanides. Liver of sulphur is normally
obtained as a semi-crystalline solid, readily soluble in water.
In the presence of air and moisture it undergoes oxidation which
is accelerated by light and it loses it’s (disgusting) smell and
power to blacken some metals. Silver, copper, brass, and low
carat golds blacken when these thoroughly cleaned metals are
immersed in a warm solution of liver of sulphur. It cannot
blacken pure gold or platinum. The solid should only be made up in
solution as required, as it will lose it’s blackening power in a
day or so. The solution should be discarded as soon as the work
is finished. Washing small amounts down the toilet or sink will
cause little harm to the environment as it will be rendered
harmless long before it even gets near the sewage treatment
plant. The solid must be kept in a really air-tight jar away from
light, air and moisture, and can be stored for years in properly
sealed jars, away from light.

Calcium polysulphide is sold in gardening shops as
’lime-sulphur’. It is a yellow, evil smelling liquid (yes,
rotten eggs!) which works quite as well as liver of sulphur, is
easier to get, and cheaper. Gardeners use it as a fungicide. Use
it exactly the same way as liver of sulphur.

The alkaline polysulphides smell of rotten eggs for the same
reason as the eggs, due to the production of hydrogen sulphide
gas. When I was very young, (a hundred years ago - or so)
naughty little boys would buy little thin-walled glass capsules
from the local ‘Joke Shop’ which they would surreptitiously drop
in the classroom, cinema, in people’s letter boxes and anywhere
else they thought it might cause a problem. The capsules
contained ammonium polysulphide.

A certain very naughty boy I well knew would mix iron filings
and sulphur, set fire to it, and grind the resultant iron
sulphide to a coarse powder. He would wrap a pinch or two of the
black powder in greaseproof paper, and having added a few drops
of vinegar, stuffed it into letter boxes of people he didn’t like
or who had caught him being naughty in other ways and walloped
him. (very deservedly, usually) He always managed to get away
with the H2S ploy because he could run fast.

More than you ever wanted to know about liver of sulphur et al.
Cheers

        /\      John Burgess
       / /
      / /      Johnb@ts.co.nz    
     / /__|\
    (_______)  And Mapua, NZ is a pleasant spot even in

midwinter
-3C last night. +12C today cloudless sky and the sun is
hot!


#6

Hi, Has anyone ever just tried using eggs? I know they tarnish
the silver in the sink. But not sure how it would hold up long
term. "A certain very naughty boy I well knew " Gee, John- you
seem to know an awful lot of detail here, spill the beans. It was
you right?


#7

Hi all

Also I am glad to be able to add a little to a John Burgess
comment (and perhaps also a little proud, - as John’s comments
always are very correct and informative, - are you a chemist or
chemical engineer yourself, John?).

When we talk about oxidizing of silver (and the like) actually
we are not oxidizing the metal but giving it a layer of metallic
sulphide.

I Have used liver of sulphur and some of the other sulphur
products for the blackening of silver and similar, but
eventually I found a chemical manufacturer here in Denmark, who
makes a special solution for the purpose.

The label says: Selenium oxidazion liquid, and according to same
it contains: Selenium (Se) abt. 2,5 pct. in the form of
sodiumselenosulfide (or -sulphide), abt. 5,0 pct. It is a water
solution, quite caustic, but with a low toxicity.

The colour obtained is ranging from pale grey to deep black with
no hint of the brown which you might see using potassium- or
ammoniumsulphide.

My first one litre bottle stayed alive about two years but then
died, probably because I dropped some silver in it and forgot
about it. My second litre is now on its fifth year and still
very well functioning. It is kept in a plastic jar in the shop
with no special precausions to light and/or humidity, and I
simply dip small items directly into it or paint it on larger
items, - here it is imperative to use a nylon brush.

When you paint - or dip - you can dilute the liquid with up to
ten times the quantum of water. This will give you a longer time
before your metal will be coloured. I have found that a 2 : 1 or
3 : 1 solution gives you the best results and, by the way, that
the colour obtained by the Selenium-liquid is longer lasting
than any of the ones mentioned in John Burgess’ comment.

If anybody wants to go further into the subject, I can only
recommend Richard Hughes and Michael Rowe*s “The Colouring,
Bronzing and Patination of Metals”, ISBN 0-500-01501-5, Thames
and Hudson. It contaions 69 recipees for colouring silver and an
innumerable number of recipees for copper, brass, bronze and the
like, - but by the way they do not mention potassium selenium
sulphide!

Hope this helps for you, it has for me.

Kind regards
Niels L=F8vschal, Jyllinge, Denmark
@L_F8vschal
phone (+45) 46 78 89 94


#8

I had some general questions about liver of sulphur and other
concoctions used to darken metals. I have been experimenting
with liver of sulphur and sterling silver and have been only
marginally pleased with the results. I guess I was expecting a
darker black, while I tend to get a very bluish-gunmetal grey
color with a matte finish. I suppose the trick is to polish
afterwards if you want to regenerate some of the shine. Does any
one have a favorite technique to polish after using liver of
sulphur on sterling? I’m looking for an “antiqued” effect with
dark black in the crevaces and a lighter, shiny finish on the
raised areas.

Maybe I should try a different chemical combination to achieve
this effect? Do share your opinions on which "oxidizing"
solutions are better/worse and for what reasons.

Thanks in advance!
Trina

Katherine (Trina) McMahon, Graduate Student and Goddess of Funkosity
631 Davis Hall, University of California, Berkeley, CA 94720
@kmcmahon http://www.ce.berkeley.edu/~kmcmahon


#9

Hi Trina, When I use liver of sulfur, I heat the solution then
dip the piece into it. If I don’t get the color I’m looking for,
I several more times. You must be careful not to get the
solution too hot, it will peel off the silver.

Terri Collier
Dallas, TX
@scollier


#10

Hi Trina: In my experiance, the dilute hydrochloric produces the
deepest oxidation. you don’t need pure acid, but you need
stronger than muratic {available in hard ware stores}. If I am
Not Mistaken, Swest may have what you need or Rio Grande. Your
chemical dealers will have that too. Hope this helped. Ringman
John Henry


#11

Hi,

It’d help me to suss this out if you’d describe your method. I
do thin (not heavy) layers of hot (not boiling) dilute liver of
sulphur. rinse in hot water between each dipping. The colour
builds up. Polish by hand with a lightly rouge-charged felt
stick.

Bri

B r i a n A d a m J e w e l l e r y E y e w e a r
@Brian_Adam1 ph/fx +64 9 817 6816 NEW ZEALAND
http://www.adam.co.nz/ back from the USA


#12

LIVER OF SULPHUR:

I guess I was expecting a
darker black, while I tend to get a very bluish-gunmetal
grey color with a matte finish.

The conversion of the surface of sterling to silver and copper
sulphides will produce the kind of finish such as you experience,
and to get the maximum black. the workpiece should be polished
and must be perfectly clean and free from all traces of grease.
The sulphuretting solution, whether liver of sulphur or
lime-sulphur should be strong and fairly warm. The work should
be left in the solution until no further colour changes take
place, which should occur in only a few minutes. The work should
be thoroughly rinsed under the tap, dried by warming until the
work is quite hot to the touch (about 60C) Even then blackening
is not durable and will wear off in a few weeks. If the blackened
work is polished using a gentle abrasive such a rouge, the
surface where the polishing buff removes the sulphide can take on
a brilliant polish, whilst of course, the crevices and
indentations will remain black, giving an antique effect which
may be desired. I don’t think a really durable SHINY black is
possible; certainly not by polishing after the blackening
treatment.

Even an application of niello, a compound of silver, copper,
lead and sulphur is not a true black, but a very deep blue-black,
but is far more durable. A recipe for niello may be found in Tim
McCreight’s book, ‘The Complete Silversmith’ - but beware! Making
niello can be hazardous to one’s health. In the process of
making it large volumes of choking, poisonous sulphur dioxide gas
is given off and breathing it can be very unlucky - even if you
aren’t superstitious. The experience isn’t at all funny - I
KNOW!

There are other blackening chemicals available, including some
containing arsenic, but I think that none give a true deep black
with silver. Gun Blue is often suggested, but it’s very name
gives away the appearance. Sorry I can’t be of more assistance
that that. Cheers now, –

        /\      John Burgess
       / /
      / /      Johnb@ts.co.nz    
     / /__|\
    (_______) Mapua NZ is a pleasant spot even in midwinter

#13
I don't think a really durable SHINY black is possible;
certainly not by polishing after the blackening treatment. 

well, it depends from the type of surface you have t begin
with… i do get it (silver and sometimes even copper) ‘black &
shiny’, i usually add a few drops of ammonia (household will do)
to the solution and rinse it under water helped by a brass
brush…

happy i day,
emanuela

oakland, california
http://www.sirius.com/~ema


#14

Trina, I’ve gotten an extremely durable “black” (not true
black, however, but very dark gunmetal gray) by using the
solution in a vibratory tumbler. (Of course, this method may not
be suitable for all pieces.) As I mentioned in an earlier post, I
use ammonium sulfide, but there’s no reason liver of sulfur
wouldn’t work as well. You don’t want it to tumble very long -
five to 15 minutes should do it. At some point the color will
start to come off the metal, but this is where it gets
interesting, because you can use to same tumbling process to both
put it on and take it off the highlights. I’ve noticed that the
pieces do have more sheen this way, even in the blacks, and I
have been hard pressed to polish off the color by hand when I’ve
tried, except by using something fairly abrasive.

Rene Roberts


#15

Emanuela, Have you tried using 950 cobalt platinum, polished it
and then heated it until it oxidizes. I believe it will keep
it’s polish and take on a nice dark patina.

Good luck,
etienne perret


#16
     I don't think a really durable SHINY black is possible;
certainly not by polishing after the blackening treatment. 
I do obtain a shiny black in this way: 

The pieces are polished and cleaned thoroughly, final step

being tumble polishing with stainless steel shots, a mild fluid
handsoap and a few drops of ammonia in three hours. Taken out of
the tumbler and not touched by hand, rinsed under the tap, dipped
in a aquaeus solution of sodium seleno sulphide, rinsed under the
tap. Thery are now black and quite matte. Those I want to be
shiny and black are then tumbled again exactly as first time, but
for about an hour. It is quite imperative to clean your shots
very thoroughly after you had the oxidized pieces in the
tumbler.

This has worked for me, but you have to remember that the

oxidation is just an outher layer and will eventually wear
off, when/if the piece is subjected to wear. By the way, I find
the tumbled finish lasting longer than those not tumbled, but I
have not done any serious investivgation here.

Regards from rainy, windy Denmark.
Niels Loevschal