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Jewellery disintegrating in cleaner


#1

I use a hot solution of water and sodium bisulphite (drain cleaner)
to clean jewellery before working on it. It also does a swift and
beautiful job of removing engraver’s shelac. Several times in the
last year I have taken light rope chains out of the cleaner only to
find that they are ruined. They practically crumble. I still do not
know if the chains were like that when they came into the store or my
cleaner ruined them. I replaced the chains at my cost so I would like
to know if anyone out there can shed some light on this. I know
sodium bisulphate will disolve opal, amethyst, glass and other silica
based materials but I was unaware that it would damage precious metal
alloys.

Robert Hood


#2
   I know sodium bisulphate will disolve opal, amethyst, glass and
other silica based materials but I was unaware that it would damage
precious metal alloys.   

Robert:

I think it’s your name – you are merely taking from the poor and
giving to the rich. Sorry, I just couldn’t resist.

Maybe the gold is just soluble enough that these fine chains are
dissolved enough to crumble.

Roy


#3

Sodium bisulfate is the WRONG stuff - it makes sulfuric acid and
is used as a pickle and possibly as an etchant. . It is not drain
cleaner. Lye , NaOH, caustic soda, sodium hydroxide is the drain
cleaner and is a base the opposite of an acid. Hot sulfuric acid
will destroy organics but also some metals will go with it. NaOH will
also destroy organics and will damage some gem stones by breaking up
silicates. I would suggest you use an ultrasound with detergents
recommended for it. An ionic type cleaner like the Speedbrite may
also help. Jesse


#4

I have seen this condition in small hollow chains and herringbones.
The gold is brittle, some to the point that the metal crumbles. and
this is a as the customer brought the jewelery in. So it may not be
your solution that you clean in altho it does sound caustic. I am
not sure of the name of the product in which we use, we get it in a 5
gal drum, and this is a very, very concentrated solution, works great
for taking roughe out of the piece, but for human goo we use smaller
containers of simple green with wonderfull results. dos anyone have
any sugestions to what causes gold to become brittle to the point of
crumbling??

Ringdoc


#5
I use a hot solution of water and sodium bisulphite (drain cleaner)
to clean jewellery before working on it. 

G’day; Please understand that there is a considerable difference
between sodium bisulpITE and sodium bisulphATE. I won’t bother you
with chemical formulae here, but both are usually seen as white,
water soluble powders. Bisulphate solution is quite acid, and we metal
smiths use a solution to clean the blackening and tarnishing found on
sterling silver and lower carat golds because it dissolves copper
oxides and silver sulphide produced on strong heating - the
ubiquitous ‘Sparex pickle’ Also used to control the acidity of
swimming and spa pools. (Much cheaper when bought from a spa supplier
than a jeweller’s supplier.) It will, however, gobble pearls, lapis,
haematite, opals, blue john and similar stones.

On the other hand sodium bisulphite is not at all so acid. One of
it’s main uses in a 1 - 2% solution is for sterilizing, due to the
instability of the sulphite part. Sulphur dioxide and sulphurOUS
acid is produced with water, and these are death to bacteria. That is
what I use every month to sterilize all my equipment, bottles, caps,
etc when I make a batch of home brew . It wouldn’t be much good at
cleaning drains. One would preferably use very hot sodium hydroxide
(lye) for that as it ‘munches’ up fats easily, which are often what
blocks drains.

There are very many better cleaners available for jewellery. One I
haven’t seen mentioned often in Orchid as a jewellery cleaner is the
’De-Solvit’ citrus type of hand cleaner. A little of this on a
toothbrush works wonders and won’t mess around with the softer stones.
A hand-hot solution in an ultrasonic cleaner works even better and
doesn’t create heaps of foam. You can see dirt and grease being
blasted off by cavitation.

  ...(Sodium bisulphite)...    It also does a swift and beautiful
job of removing engraver's shelac. 

Wouldn’t common simple grain alcohol be best at this?

    Several times in the last year I have taken light rope chains
out of the cleaner only to find that they are ruined. 

I too wonder what those chains could be made of that would cause them
to crumble. Could they possibly have been anodized aluminium -
which dissolves in an alkali like sodium carbonate? (washing soda) or
lye (caustic soda). I have come across such chain - so El Cheepo as
to be virtually useless.

    I know sodium bisulphate will disolve opal, amethyst, glass and
other silica based materials but I was unaware that it would damage
precious metal alloys. 

Sodium bisulphate will not dissolve amethyst, glass or siliceous
materials. But caustic soda (lye) will. Eventually. It will not
dissolve any alloys of precious metals I know of. Cheers, – John
Burgess; @John_Burgess2 of Mapua Nelson NZ