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Bombing


#1

How do you bomb gold? Please share any info.

Rael


#2

Hello Rael, Put 1 quart of water into a 2 quart plastic container. This
water needs to be at 100 deg. F. Add 2 dwt. of cyanide. When it has
dissolved, add 3 ozs. of the hydrogen peroxide that is used to bleach hair
[ 10 per cent pure]. Have the gold you want to “bomb” clean and in a sieve
[the kind used in the kitchen]. Swish the metal around for about 2
minutes. Remove the sieve, rinse it under hot running water and then place
it in a weak cyanide bath for about 30 seconds. Rinse the gold under hot
running water again and then steam it off. This process is also called
chemical stripping. The solution can only be used once and must be
disposed of at once. It will foam up in an ugly brown stuff after about 3
minutes. Don’t let it surprise you.There is no metal loss and the process
is especially good for discolored gold such as soldered mesh watch bands
and delicate castings. 1 batch will “bomb” 100 dwt or 5 dwt, it makes no
difference. The only drawback to the process is that if you are not
careful, you can get dead. Use good ventilation and don’t drink the stuff.
Wash your hands and don’t bite your fingernails. If you are careful, you
will not believe your success. Tom Arnold


#3

Tom,

In response to your post about bombing.

PLEASE, PLEASE, PLEASE DO NOT POUR THE CYANIDE DOWN THE DRAIN.
That small batch of cyanide is going back into the water
system… dilute with equal parts of bleach to neutralize the
cyanide.


#4

Okay Rael, I’ll answer your question as to how do you do bombing?
Chemical bombing of gold is a cyanide - peroxide process. If this
process is done indoors you must have very adequate ventilation,
wear eye protection, wear both a chemical and dust respirator ( a
gas mask available through wholesalers such as Rio Grande,
Gesswein, Swest ) wear good gloves ( surgical gloves do well )…
protect yourself… This response is for l purposes only
and you should have someone actually take you through this process
or read a good book on it…there must be some . I learned this
through trial and error and do not consider myself an expert. I
have found this process to be very useful for custom rings and
pendants or whatever where the customer is adamant about using the
"old gold" they brought . It helps even out the color and look of
the piece after it is finished. I generally bomb after I am
finished with a piece.(sentence structure poor ). For the past
several years using the commercially available ‘magic cast’ has
somewhat eliminated any chemical bombing I might have done. I bomb
one piece at a time, usually. Sodium Cyanide , the eggs as they are
called, is all I have used. one egg is equal to about one ounce.
Sodium Cyanide is available still through Gesswein. Hydrogen
peroxide - available through any beauty supply store - 40% by
volume…through trial and error this is all I have found to be
successful. Weaker solutions do not work well and stronger
solutions of peroxide blow up too violently.

Here it is…for one or two rings

Mix one egg with about 30 fluid ounces of water ( actual formula
is one gallon water to ten ounces cyanide or one egg to a tenth of
a gallon water ) Heat this to about 140 degrees pour hydrogen
peroxide into cyanide solution ( ratio is 2parts cyanide to one
part peroxide) If you do this slowly solution should not erupt (
but in my experience I never really know for sure) Chemical process
takes less than 30 seconds Remove your gold work and be very
careful to clean, clean , clean any remaining chemicals off of your
work. If you do a lot of this you can plate out any gold in the
solution by attaching stainless steel small plates to both leads
and turn rectifier to about 4 amps and the remaining gold will
plate onto the steel. Dispose of the remaining liquid in a proper
manner

I might add that there is a cloud of toxic fumes that comes off
this mixture so be very careful and please use a gas mask and
gloves and eye protection.

Let us know how you make out with this as I found the finish to be
very pleasing when I did a lot of casting of old gold

Terry Parresol in Central Florida


#5
      This process is also called chemical stripping. The
solution can only be used once and must be disposed of at once.
It will foam up in an ugly brown stuff after about 3 minutes.
Don't let it surprise you.There is no metal loss and the process
is especially good for discolored gold such as soldered mesh
watch bands  and delicate castings.  

And what, pray tell, Tom Arnold, is this ugly brown stuff that is foaming
up? Better safe than dead! Rose McArthur


#6

How do you bomb gold?

Rael, Stay away from it!!! It’s a Very Dangerous process that
involves heating a water/cyanide solution to boiling and then
adding concentrated hydrogen peroxide…The vessel builds up
pressure and “pops” the lid off - hence the name “bombing”. Nasty
stuff! We used to do it years ago, but with modern finishing
procedures (like tumbling and stripping), I wouldn’t go near the
stuff again. Ken


#7

Terry, thanks for the recipe, now all I need is proper
ventilation, I’ll let you know how it works as soon as I get the
chance.

Rael


#8
And what, pray tell, Tom Arnold, is this ugly brown stuff that
is foaming up?  Better safe than dead! Rose McArthur 

Not for the light harted.The stuff bugs me to DEATH. have some one
show you how. BAD stuff.


#9

Dear Ken and Rael et al…

I find myself wondering how on earth some processes develop.

I mean, really. Would anyone in their right mind pick up a beaker
of cyanide, mix it with boiling water and hydrogen peroxide, just
to see what it would do to gold? I know, I simplify. But it never
ceases to amaze me how some things come to be.

A puzzled Rex from Oz.


#10

Dear O.B. MacArthurs,

In reference to your statement that there is no metal loss in
left over bombing solution is incorrect. After saving the bombing
solution in tight sealed 5 gallon container, the solution was sent
to a local refiner, they recovered over 2.25oz fine gold. If you
neutralize the bombing solution, with equal parts of bleach, our
return from the refiner have been little, at best.


#11

PLEASE, PLEASE PLEASE, will someone inform us as to what damage
potassium or sodium cyanides can do to the environment. To the best
of my knowledge, these chemicals break down pretty quickly in the
environment. Unlike say, lead, mercury, nickel, kepone, sulfuric
acid, petroleum distillates or even plastic. Seems as if the very
word cyanide strikes utter terror in some hearts.

Some years ago I was negotiating to buy a store from a fellow
whose son had, the previous holiday season, drunk gold plating
solution, and was dead before the ambulance arrived. Certainly
some caution should be used in the handling. Handled improperly
someone can get hurt.

Even bleach is toxic, but the oceans are full of it.

Sincerely,
Jerkface


#12
          This process is also called chemical stripping. The
solution can only be used once and must be disposed of at once.
It will foam up in an ugly brown stuff after about 3 minutes.
Don't let it surprise you.There is no metal loss and the process
is especially good for discolored gold such as soldered mesh
watch bands  and delicate castings.  
And what, pray tell, Tom Arnold, is this ugly brown stuff that
is foaming up?  Better safe than dead! Rose McArthur 

Aw heck. can’t let it go a second time.

There IS metal loss. Just not much. Like electrostripping, at
least a little of the gold is removed from the surface. THAT is
what the brown color is from, for heavens sake. Hot solutions of
cyanide, especially with peroxide in there as well, are dissolving
metal at a fairly significant rate…

Now, on a normal cast or fabricated piece of jewelry, you’ll bomb
off less than you migh polish, and if you get the process working
right, you’ll get a nice workable finish will less metal loss than
by actual polishing. But occasionally, for example, one has to
bomb a piece several times to get it right. If that happens to be
a repaired thin hollow rope chain, where the metal is very very
thin you may find yourself having bombed too much off the piece…

In my view, though, the above is only an example why hollow rope
chains are trash, and not a reason not to bomb. And, for that
specific type of item, I frankly know of no other method that is as
effective at taking a worn looking piece of jewelry and restoring
it to a really sparklingly clean and bright like new look. You can
polish the outside of a chain, but not inside all those little
crevices where bombing is just as effective. Even electrostripping
on such items doesn’t come close. Magnetic tumblers, with their
tiny pins, are the next best bet, but not as bright a finish…

Now then. How I do it…

First off, I prefer to bomb with Potassium cyanide instead of the
sodium. Seems to have more of a kick to it, and goes brighter.
You can get cans of granular KCN from Vigor.

I use boiling water. Usually about a half cup, with only a small
batch of jewelry at a time. I do this in a half gallon plastic
pitcher, with an old gallon plastic gallon milk container who’s
bottom and half of the front has been removed as a spash sheild.
(more on that in a moment.) A generous teaspoon or so of the
cyanide powder is dissoved in the boiling water, either before or
after the jewelry is added. The Peroxide I use is 30%, stronger
than usually sold for hairdressers use. nasty stuff. will burn
your skin. For the above amount of water and KCN, I add about 2
table spoons or so of peroxide. maybe a little more.
IMMEDIATELY, the milk jug/splash shield is placed over the pitcher,
AND HELD DOWN. The key here is that it’s a very loose lid, doesn’t
seal anything. Just diverts any splash back down into the plastic
laundry tub I use underneath. This is, of course, all done with
good exhause ventiallation.

while many people who bomb use lower temps and concentrations, I
WANT my solution to explode. The better the “POP”, the better the
finish. Without that pop, the gold will be real clean, but it
won’t have become bright polished as well. Done 2 or three times,
this can bring a piece of gold sheet from the finish left by a
plain rolling mill to a bright surface that’s only slightly
imporoved by rouge, and doesn’t really need it. Since many of my
pieces are intricate constructions almost impossible to
conventionally polish, I find bombing to be invaluable. it will
not only leave a nice final finish on all the recessed areas, but
it will remove any soldering discoloration or fire scale from the
gold as well. Note that different alloys respond differently.
Standard 14K yellow golds seem to work the best. higher copper
content makes it less polished, and sometimes spotty. More silver
content makes it brighter. Apparently, the zinc in many 14K golds
also helps. Many 18K golds don’t respond as well, sometimes
comeing out not bright, but showing instead an etched crystaline
finish, which would me nice if it were more intense. White golds
tend to go matte, not bright. So all in all, I find this most
useful for 14K yellow work.

Also, a note on the chemistry. I’m not a chemist, but I’m told by
several folks who are, that what’s left, that brown residue, is not
cyanide anymore, but cyanate. The peroxide oxidizes the cyanide to
cyanate. Cyantes are still not benign compounds, mind you, but
they are a good deal less toxic than the original cyanide. So long
as you’ve used sufficient peroxide for the reaction to complete,
the wastes are not as toxic as you may have thought. Still, handle
the stuff with the respect due to such materials. The waste may
contain sufficient gold to warrant saving it. I put it into a wide
mouth container on a low temp hot plate that will evaporate the
stuff, producing either a concentrated sludge or dry mass
(depending on how often I add to that flask) When sufficient
material has been saved up, it can be refined for the gold. Not
much, but enough to be worth the bother even so.

Hope this helps.

Peter Rowe


#13

Hi Brent, You have evidently gotten my post confused with someone
else’s. My comment had to do with the danger of the process, not
about recovery from the solution. O B McArthurs


#14
  PLEASE, PLEASE PLEASE, will someone inform us as to what
damage potassium or sodium cyanides can do to the environment.
To the best of my knowledge, these chemicals break down pretty
quickly in the environment. Unlike say, lead, mercury, nickel,
kepone, sulfuric acid, petroleum distillates or even plastic.
Seems as if the very word cyanide strikes utter terror in some
hearts. 

Your right of course. Cyanide is not actually all that bad, so
far as toxins go. For one thing, it takes a rather measurable
amount to kill ya. Like about 200 to 300 milligrams. Not much,
but still more than a faint residue on some tool. Compared to
many of the toxins society has to worry about, it’s almost benign
by comparison. Consider, for example, dioxins. The amount
almost guaranteed to eventually cause cancer is almost impossibly
small, by comparison.

And, treated quickly enough, cyanide poisoning is treatable.
Amyl Nitrate, for example, competes successfully with hemoglobin
for the cyanide ion, preventing asphyxiation (the quick cause of
cyanide caused deaths) if administered quickly enough and in
enough quantity. The trouble is, however, with cyanide
poisoning, the stuff kills you so goddam fast that in most such
cases, the victims had no time to seek or summon help. The stuff
has a mild enough smell, even, that victims might not even have
known until starting to loose conciousness, that they were in
trouble. It’s for this reason that cyanide needs to be handled
with such utmost care. In cases of less than lethal exposures,
it turns out that the liver is actually fairly good at
detoxifying small amounts of cyanide. Chronic exposure over long
periods of time can cause liver damage however, so don’t push
your luck on this.

As to the environment, the problems are dual. First, while a
single jewelers flushing a small amount of bombing residue down
the toilet is not going to be doing great harm, a whole
building’s worth from a cities jewelry district, or a major
manufacturer, dumping their cyanide into the waste water, is
going to be putting enough of the stuff into the system that
municipal waste water treatment facilities will suffer. Cyanide
kills some of the bacteria that make such systems work. In small
quantites, it’s not a big problem, and even occurs naturally in a
number of plants. Even edible ones. Peach pits, for example,
contain small amounts of cyanide… The other part of the
problem is that usually the dumped cyanide is also accompanied by
metallic wastes as well. Gold isn’t a problem, much, but copper
can be. And people dumping bombing residues might also be
dumping their nickle plating salts. That too is pretty bad,
even in small amounts. And there’s another problem. Drains
have this thing called a trap. If some idiot dumps their cyanide
down the drain, and doesn’t then flush enough water down the
drain to eliminate it from the trap, and then decides his pickle
pot needs changing too, and the pickle mixes with the cyanide in
the trap and bubbles up enough HCN gas, you’ve got one less
stupid jeweler in the world…

The simple answer is this. Although one can argue all about the
relative safety or danger of cyanide or other chemicals and
materials, almost anything can be dangerous if used in ignorance.
Cyanides present extreme dangers to careless and uninformed
users. Used correctly and with proper awareness of the dangers,
it’s quite possible to work safely with even large quantites of
the stuff. In industry, it’s done routinely. Very useful
chemistry. If you choose to use cyanides, you can use them to
effectively get some very good results not attainable easily by
other means. Or you can use them to get dead. Knowledge and
careful lab technique is the difference. To use them safely,
you MUST be strict on your procedures, from storage to use to
waste disposal. Know what you are doing and why your doing it,
and what can go wrong, then prepare for it. This isn’t rocket
science folks. It just needs care and vigilance. You can’t
become complacent with these things. Bring your luncheon
sandwich into the plating lab and set it down, do some work, and
pick it up again without washing your hands, and your
carelessness can cost you your life. I work with cyanides
routinely in my home shop. That would not be the case if I had
children in the house. And even so, the stuff stays locked when
not in use, just to protect potential visitors or even prowlers
(god forbid). And in use, though I may appear casual, you better
believe I’m very aware of what I’m using and how. Done like that,
I’m pretty sure I’m not in any danger.

Hope this helps.

Peter Rowe


#15

dear peter

thanks for the informed non panicking reply about bombing. I’ve
been doing it for years, and when i have the magic mixture just
right, the gold comes out very shiny. My problem is that it
doesn’t always come out right. I’ll take customer’s extremely
tarnished gold, and when ultra sonic cleaning doesn’t work, i’ll
offer to bomb, without the complex explanation. Invariably, i
work into a problem. My own stuff will come out just fine, but
the customer’s batch will be dark, or often brown in color.

I usually set up a pot of dissolved cyanide into water, and keep
it ready to boil when I need it. I then pour it over the gold in
a pyrex flask, just enough to cover the gold. Then I pour over a
small amount of 30 or 40% peroxide (whatever my local beauty
supply house has) and wait for the reaction (I installed a good
vent many years ago)

Sometimes it works great, others it does not. Is there a magic
formula??

thanks
allan freilich


#16

My plumber told me that here in the State of Maryland, they have
a tracer chemical that can trace the source of cyanide that is
dumped down a drain, toilet, etc. and that if it is traced back
to you, there is an enormous fine. It apparently had something to
do with the massive pollution of the Chesapeake Bay. The proper
way of disposing of it is to send it back to the supplier or
manufacturer for disposal by them. Anyway, doesn’t cyanide,
when it is mixed with something, turn into a gas and isn’t that
gas what is and was used in gas chambers? And if cyanide is so
safe, why are manufactuers trying to make plating solutions that
are cyanide-free?

Iris


#17

Thanx guys on your input about bombing, I feel that information
will be kept in a safe place with me. It seems that there is
always more than one way to cut a chicken. Keepn’ it …Rael


#18
   thanks for the informed non panicking reply about bombing. 
I've been doing it for years, and when i have the magic mixture
just right, the gold comes out very shiny.  My problem is that
it doesn't always come out right.  I'll take customer's
extremely tarnished gold, and when ultra sonic cleaning doesn't
work, i'll offer to bomb, without the complex explanation. 
Invariably, i work into a problem.  My own stuff will come out
just fine, but the customer's batch will be dark, or often
brown in color. 

Extremely tarnished GOLD? That’s a warning sign to you that the
alloy isn’t a standard 14K, since 14K shouldn’t tarnish, should
it… As I mentioned, alloys other than the standard 14K ones
seem to be less reliable with regard to actually coming out
bright polished. And if your own stuff is coming out fine, then
I’d guess you had the mix as right as it is gonna get.

Do keep in mind that I’ve not done a thorough research into
different bombing procedures. I’m just doing it the way I was
taught, since it’s been fine for my needs. As I mentioned, I’ve
found 18K or higher alloys, lower than 14K alloys, white golds,
and did I mention, rose golds, to be less compatible with the
way i bomb stuff if I want it to polish in the process.

In my experience, if you’ve got it “popping”, then if it isn’t
polishing, it’s not likely to do so. You can perhaps try a
slightly more dilute mix, less cyanide and less peroxide. Might
help. But more likely, be happy with the removal of the tarnish
that you should have by the time you’ve soaked it again in just
cyanide after bombing. Then, if you need it brighter and actual
polishing isn’t an option, it’s time for a short spin in the
tumbler. Steel shot will do quite a bit once the gold is clean.
Even 15 minutes or so may be enough. If you’ve got a magnetic
tumbler, then it will work even better at getting into the
crevices you’d hoped bombing was gonna fix up but didn’t…

   Sometimes it works great, others it does not.  Is there a
magic formula?? 

Probably there is. One of these years I might just sit down and
actually measure the exact quantities of water, temperaturs,
cyanide, peroxide, and gold jewelry that gives me the best
result. It’s not high on my list of projects to do though, since
the “seat of the pants” measurements I’m using by eye seem, by
dumb luck, to be pretty consistant for me. If you’re curious,
why don’t you do it and publish it here for us?

Peter


#19
  My plumber told me that here in the State of Maryland, they
have a tracer chemical that can trace the source of cyanide
that is dumped down a drain, toilet, etc. and that if it is
traced back to you, there is an enormous fine. It apparently
had something to do with the massive pollution of the
Chesapeake Bay. 

Certainly, ongoing dumping of cyanide or any other such chemical
can be traced upstream just by looking in each succeeding
upstream branch for where the cyanide is coming from. Easy
enough to test for. But a single bit of chemical, once washed
down the drain with clean water, doesn’t leave a trail to trace.
This is chemistry, folks, not voodoo. Again, if you’re using
anything but the very occasional small amounts, then you should
not by dumping cyanide down a drain

   The proper way of disposing of it is to send it back to the
supplier or manufacturer for disposal by them. 

Yeah, right. try sending your used bombing residues back to
your jewelry tools supplier who sold you the can of cyanide from
Vigor… You need to be sending it to some firm specifically
equipped to handle cyanide disposal. In industry, it’s often
handled right where it’s used, with a cyanide destruct unit.
these simply mix the waste cyanide with acid in a closed
container, generating HCN gas which is then absorbed in filters
capable of doing so. Don’t try this at home, kiddies. That
reaction is the exact same one used to operate the california
gas chamber… Commercially, larger quantities of dry cyanide
are destroyed by incineration. Again, it must be done properly
for safety. Oxidation with bleach or peroxide is only a partial
step. A big one, but still leaving wastes needing treatment.

   Anyway, doesn't cyanide, when it is mixed with something,
turn into a gas and isn't that gas what is and was used in gas
chambers?  And if cyanide is so safe, why are manufactuers
trying to make plating solutions that are cyanide-free? 

Iris, the above paragraph precisely illustrates why
manufacturers are making plating solutions without cyanide.
First off, neither I nor anyone else has said that cyanide is
safe. Only that it’s dangers are relative to the procedures used
and the knowledge and precautions used by the user. It should
not be used by those who’ve not familiarized themselves with
it’s use and chemistry. You appear to a be a fine example of
this, since a “mixed with something” degree of knowledge about
cyanide would make you a very dangerous person to have around the
stuff.

For your idification and continued education, the something is
virtually ANY acid of sufficient strength. that can even be
orange juice if there’s enough of it. If the ph of a cyanide
solution is lowered by mixing with enough with any acid, be it
pickle, or fruit juice, stomach acid, or HCl from an actual acid
bottle, then it reacts with the cyandide salts (potassium or
sodium cyanide) to form a potasiom or sodium salt from the non
hydrogen portion of the acid, such as sodium nitrate from nitric
acid). The now free cyanide ion then combines with the free
hydrogen to form hydrogen cyanide, HCN. This is a colorless and
mostly oderless gas (mild almond smell) which will be released
as gas from the solution.

In very low concentrations, traces of HCN won’t do more than
give you a mild headache, and if you look, your fingernails will
look a little oddly blue. A good nights sleep will fix ya up.
Still something to avoid, of course. Especially on a chronic
basis, as it will cause liver damamge over time. Higher
concentrations will, over a couple hours, cause convulsions and
CNS (central nervous system) problems that can be treated and
over a few days sometimes be cured depending on the dose
recieved. But if there’s enough of it, and it doesn’t take much,
then asphyxiation can kill you in merely a few minutes. The CN
ion reacts chemically quite a lot like oxygen, you see, and binds
to hemoglobin molecules the same way, only it then doesn’t get
used by the body, so if there is enough HCN in the air, your red
blood cells bind to it instead of to oxygen, and you asphyxiate.
Pretty quickly. Just like drowning in it’s time scales, with the
added gotcha that excess CN is also interfering with nerve
functions too.

As I said, if you get a victim to fresh air and treat it quickly
enough with the right stuff, you can often prevent death, as all
you need do is tie that CN ion to something else, like amyl
nitrate, instead of the hemoglobin and then your body can
transport oxygen again. But doing this quickly enough is the
kicker. A call to 911 gets you a fire station crew who doesn’t
get there quite in time, and if they did, chances are they don’t
have a cyanide antidote kit right to hand in any case.

If you do a significant quantity of plating or bombing with
cyanides, an intellegent thing to do would be to obtain a cyanide
antidote kit to keep on the premeses. And then get an MSDS for
the stuff, and learn what all that mumbo jumbo actually means.
Learn enough basic chemistry and common sense lab technique that
it makes sense, and you know what you’re doing around chemicals
of any sort. You don’t need advanced degrees to do this. You
DO need a good head, and a healthy respect for the stuff, and the
willingness to follow all the rules needed for it’s safe use even
once you’ve gotton familiar and comfortable with it. THAT is the
time it gets most dangerous, if you get careless as a result.

Hope this helps.

Peter Rowe


#20

Dear Peter:

Thank you very much for your detailed explanation of the uses
and hazards of using cyanide. I do not profess to be a chemist
but I do know that I cannot use it because I am not properly
educated in the use of cyanide. I have not found too many people
willing to teach the proper use of it and I can now understand
why.

I think that your explanation helped clear up the "mysteries"
surrounding this time-honored technique.

Once again, thank you.

Iris