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Letter 196
Electroplating for a school science
project
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My 5-year-old son wants to do a science fair project on
plating. He saw someone on TV plating something and he asked
me if I knew how to do it. When I was a kid, a science fair
exhibitor plated copper pennies with silver. Do you know
someone who can tell me how to do that? It seemed like a
simple thing, but I don't know any details.
Darrell Ostler
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For this age group, Darrell, a simple immersion deposit
might be more practical than electroplating. Get
copper sulfate [link is to product info at Amazon].
Then get some simple coins or small parts, clean them with
toothpaste and a toothbrush (good to remind the kiddies
anyway), then vinegar or lemon juice, rinse them well, and
put them into the copper sulfate.
Copper will deposit on them.
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Ted Mooney, P.E.
finishing.com
Brick, New Jersey
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Thanks for posting my inquiry and the response. I think I
will try the immersion method on a few nickels just to turn
some heads. I would still like to do the simple
electroplating on copper pennies though. My son gets very
excited about electricity and batteries and such. In his
mind, if a science experiment doesn't use electricity, it
isn't science.
So, do you have a simple "recipe" for silver plating some
copper pennies? I know you are probably busy and would
prefer to receive revenue generating inquiries, but I've
looked everywhere and can't seem to find anyone who knows.
The local plating shops don't want to give me the time of
day, and you're obviously an authority. You are the best
contact I've found. Anything you can do would be sincerely
appreciated.
Lastly, I think you have a solid web page. Not too flashy
(which is good in my book), but it is packed with a lot of
very useful information.
Darrell Ostler
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My middle-school son wants to do a plating demo as a
science fair project. And, yes, I did suggest this based on
a demo I saw years ago. What I saw was plating of pennies
using a silver spoon as an anode. We were led to believe the
bath was simply water, although I now have come to learn
that was just a bunch of hooey.
I have followed your
FAQ to the point of tracking down some (a couple of
tablespoons full) silver nitrate, which, as it turns out,
was no simple task!
I've been to the library but the only bath I could find
for silver plating didn't specify silver nitrate. Can you
provide me with a formula for a small batch (1-2 liters) of
solution? Is there anything else I need to add besides the
silver nitrate and distilled water, and does the bath need
to be heated or is room temperature enough? Lastly, do I
need to use a silver source such as an old spoon or coin for
an anode, or do I use a copper anode?
Your site has been most helpful, and I really appreciate
your response.
Thanks!!
Dan Shogren
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Real silver plating is done out of cyanide, Dan, which is
a horrible poison and out of the question for a home or
school experiment. With silver nitrate you may form a poor
deposit -- sorry, but I really don't know. But the
Electroplating Engineering
Handbook says that to prepare a standard silver nitrate
test solution, dissolve approximately 17 g of silver nitrate
in a liter of chloride-free water, and store in an amber
bottle. While that test solution is not really meant to be
used as a plating solution, it sounds like as good a formula
as any :-)
Silver may not be easily plateable from ailver nitrate,
but please let us know what you find. Good luck!
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Ted Mooney
finishing.com
Brick, New Jersey |
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Hello ...
I have done a child's plating job with electricity by
using dilute cobalt chloride solution from a kid's chemistry
set. You can use either a piece of cobalt as the anode
(usually not available readily), or a graphite rod out of an
old d-cell battery. A 1-1/2 volt battery should do. Agitate
the penny while plating. It will at least look vaguely
silver to gray.
Vince Summers
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Folks,
I suppose I'm just a kid at heart, but I'm one of those
irresponsible science showmen who plate silver on things as
a demonstration. My favorite is electroless silver plating
on glass. It makes a great silver cup from a cheap glass and
you can get a kit containing methyl glucamine through LON
Lab, or you can use the older formaldehyde method with
silver nitrate.
For electrolytic plating, how about showing off the
classic woods strike. The recipe is: 1 oz
Muriatic Acid [link is to product info at Amazon], 8
oz of water, and 1 oz of Nickel Chloride (often included in
chemistry sets). Plate with 3 volts (two 1.5 V dry cells).
You can tell the kids that this strike is extensively used
in industry.
Good Luck,
Robert Buxbaum
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I'm doing a science project, for my 4th grade class, on
copper plating and I don't quite understand it, could you
please help me?
The experiment book I used says to take a small glass of
vinegar and sprinkle in a few good shakes of salt. Then put
in some dirty pennies. The pennies are cleaned of the
surface corrosion. Then take a iron nail and clean it with
steel wool. Then put it into the glass. After 5 or 10
minutes the nail will be covered with a bright coat of
copper.
Can you help me explain what is going on?
Thanks a lot for your help!
Danielle
New Life Academy
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- vinegar in a glass
Vinegar is a solution of a little bit of acetic acid
in water.
- add salt
Salt is sodium chloride. The water is a solvent that
splits the salt into ions of sodium and chloride. The
sodium ion has a positive charge, and chloride has a
negative charge. Water molecules are lopsided and are
positive on one side and negative on the other, something
like a magnet. Several water molecules surround each
chloride and sodium ion and keep them in solution. If you
add too much salt for the water molecules to surround,
you won't dissolve all of the salt and some of it will
sit on the bottom of the beaker.
- add corroded copper (it's not allowed to call them
dirty)
Copper metal (that shiny red metal) will react with the
salts from your fingers and oxygen in the air to form
corrosion products.
A very thick layer of corrosion on copper has a green
color, the color of the Statue of Liberty. (She has a
copper skin). This green layer protects the copper
underneath from more corrosion and will make Ms. Liberty
last a long time.
The corrosion on pennies keeps rubbing off by being
rubbed all day in your pocket and fingers. Even if your
fingers look clean, they always have a little oil, salts
and acids from your skin. That's why when we touch
things, we leave fingerprints.
The combination of vinegar (acetic acid and water) and
salt (sodium chloride) dissolves the corrosion products
(a mix of copper salts like copper sulfate, copper
chloride and copper oxide) into the water. You will now
have a few copper ions floating around in the water, and
you can see the bright red copper metal of the penny.
- clean an iron nail with steel wool and put it into
the glass
You need to clean the iron nail of any oils and rust
(iron oxide) before trying to cover it with copper.
Iron and copper are both metals. Iron metal has a grey
color and copper metal is red in color. But copper and
iron are a little different in behavior. Look around in
your classroom. You will see some of your friends who are
always jumping around, talking, or getting into trouble.
They are like iron. Some of your friends are quiet, and
are happy to just sit in their seats and behave. They are
like copper.
Copper is happier to sit around. Iron is happier to
get into solution in the water. In the glass you have
prepared, some of the iron metal from the nail will give
up electrons to the copper. This iron will dissolve in
the water. The copper which took the electrons will drop
out of the water and stick to the nail. If enough of the
copper sticks to the nail, you will see the red color of
copper metal.
I tried your experiment, but my pennies were not very
corroded, so I may not have had enough copper in the water
to see anything happen on the surface of the nail.
This kind of reaction is very useful, and is used every
day in science and industry to help make the things we use,
making our lives easier and more interesting. The things
that are happening in your little glass are much more
complicated than this, so you must study very hard.
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(1997)
Here is what the Rochester branch of the AESF had been
using for years as a plating demo at our annual Engineering
Fair: bright nickel plating of pennies. Sure, the setup is
not as basic as with copper plating, but no cyanide is
required and the plate is bright.
Watts-based bright nickel baths are pretty common in any
local bumper plating shop (see your phone directory under
"Electroplating services"). Pour some bright Ni solution in
a 1 l beaker, put it on a hot plate, get a small battery or
rectifier and, in combination with the toothpaste and
toothbrush cleaning technique described above by Ted - you
are in business.
Don't forget to rinse the pennies well before and after
plating and return the plating solution back to the shop
after you are done.
Happy electroplating from PlaterB!
 
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Ed. note: but times have changed since Berl's posting. No
plating shop can give you plating solution anymore. You'll
have to buy the supplies from a lab supply store unless you
own that plating shop yourself.
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I am a high school chemistry student who is planning on
doing a simple electroplating procedure for the class. I
plan on plating zinc onto pennies. This seems to me to be
much simpler than using silver. Am I correct in this
assumption?
Graham W
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I would say yes because I can plate a fairly bright and
adherent zinc coating from dilute acetate or sulfate
solutions, and I don't know how to do this with silver.
In reading the many letters on this subject, I am
starting to believe that any demonstration of electroplating
should include a demonstration of wastewater treatment. A
nice graphite sponge cathode for electrolytic recovery would
be neat.
What good does it do to show someone how to plate, if we
don't show the audience that plating requires a carefully
thought out and implemented plan for wastewater treatment?
Also mention that some plating processes, like chromium
plating, for instance, also create a mist hazard for the
operator, and this process requires ventilation and
scrubbing of the air before release to the environment.
What kind of references do you have in your high school
for electroplating?

Tom Pullizzi
platronica.com
Falls Township, PA
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I'm not sure what you mean by references; I have the
Metal Finishing Guidebook and
Directory . What is another metal that would be
good to plate onto copper?
Graham W
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That is a very good reference, I did not expect you to
say that you have one of those! There are many formulas in
that book, but I don't know how many you can use in the
home, since it is a reference for industrial users.
So you have a powerful reference, now you need to control
its power and design a good demonstration for high school
level chemistry. Have you tried to plate anything so far?
What were the results? Have you read the chapters on rinsing
by our very own Ted Mooney, P.E., and on wastewater
treatment?

Tom Pullizzi
platronica.com
Falls Township, PA
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I'm glad to hear that you think so highly of it. I got it
when I interviewed the president of a plating company. I
have never even attempted to plate anything yet. I have read
the chapter on rinsing, though I admit it got a bit too
technical for me, though I'm sure if I had any experience
rinsing it would probably make more sense.
Graham W
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Idea. Why don't you switch gears, and make your project
about... RINSING! The world does not know enough about
rinsing. Use your sources from electroplating to expand and
expound on the subject of rinsing. Rinsing the soap out of
laundry, washing the ice cream out of Breyers' containers.
Show your fellow students how much it costs the earth to
have clean cars and jeans. Hot water rinses much better than
cold water for most projects, talk about the energy cost of
rinsing and how it relates to global warming.
It is a revolting subject, this rinsing, because the
waste is a very dilute stream of milk, suds, metal ions,
petroleum hydrocarbons, etc., but I volunteer you to solve
some of our (all too human) problems. I will help as much as
I can. Good Luck. - t
p.s. You have plenty of experience in rinsing, now you
have to look at the process as a scientist, and understand
how it works. Something to do about that law on entropy. If
you line up the atoms on one object, you have to disrupt the
order of at least that many atoms somewhere else in the
universe. Result: pollution.

Tom Pullizzi
platronica.com
Falls Township, PA
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I also have been trying to help my teenager with a
science project. Many of the entries here have been helpful,
but are scattered. I have some specific questions:
1.) Can one plate copper using a copper sulphate
pentachloride solution?
2.) If so, at what strength, and at what temperature, and
at what voltage.
3.) When using old developing solution to plate silver
(silver nitrate):
- do I need a silver anode?
- what is the correct voltage and temperature?
- what is the ideal plating target?
- for how long?
All my previous attempts have resulted in a dirty black
target.
note: My local camera shop reclaims their silver. It
seems to be easy for them.
Wallace Reid
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Yes, Wallace, the thread meanders. That's the nature of
public participation, but we do have an
FAQ on "How Electroplating
Works" that is arranged in tutorial fashion and will be
reasonably easy and straight forward to follow.
1. I think you meant copper sulphate pentahydrate, i.e.,
CuSO4.5H2O.
Root Killer [link is to product info at Amazon] is
mostly comprised of 'copper sulphate pentahydrate'. This
question was answered above, and it was a qualified 'yes'
because we can't be 100 percent assured that a manufacturer
might not decide to include something besides copper
sulphate in the root killer (for example some organic
biocide like a weed killer).
2. For the purpose of a school science project, use
whatever strength you get, run it at room temperature for
simplicity, and 1-1/2 to 3 volts. As long as it has a blue
tint it should work fine.
3. I've never tried that one, but I do know that silver
nitrate isn't used for real silver plating. I think the
anode material is not critical, and see no reason to heat
the solution or apply more than 1-1/2 to 3 volts. But there
is a big difference between removing the silver from waste
like the photo shop is doing, and producing a good silver
plate. Good luck.
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Ted Mooney
finishing.com
Brick, New Jersey |
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Would anyone please help me?
I'm desperately trying to find out how to electroplate a
non-conductor, to be exact, a leaf. the leaf needs to be made a
conductor so that a coat of metal can be deposited. does anyone know
how to make the leaf a conductor? It needs to be placed in some kind
of solution, but what?
I'd like anyone that can help. Thanks
Susanne de vaal
the Hague, Netherlands
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Hello Susanne,
We have an FAQ on how to plate
organic materials. Lacquer the leaf so it will not be destroyed
by the plating chemicals; spray on a "two-part silvering solution"
where one component is a soluble silver compound and the other is a
reducing solution; then start electroplating.
Now, had you asked me how to create a Renoir oil painting, my
advice would have been to dip a brush into paint, spread it on the
canvas, and feather it in such a fashion as to give strong realistic
romantic forms but surreal lighting. But I can't sketch a horse well
enough that you'd be able to tell whether it was a cow or a dog I was
aiming for. The point being, mechanical directions are 1 percent of
the issue; the reason we find artwork beautiful is that we
intuitively recognize that it is not a simple matter of mechanical
motions; but, rather, a great amount of experience and technique, and
sometimes extraordinary talent.
Good luck.
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Ted Mooney
finishing.com
Brick, New Jersey |
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I am attempting to immersion plate a copper penny with granular
zinc in a solution of boiling sodium hydroxide. I used a 0.1 mol
solution. Was this the correct molarity? When I conducted the
experiment, one side of the penny became dull grey and the other side
didn't plate at all. Do you have any idea why this was?
Graham W
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Graham,
I hope this is something you are doing under proper lab
conditions, with supervision. Boiling sodium hydroxide is really
dangerous stuff, even without the zinc dust. This may not be
something you should be doing for/with your high school class. But I
don't see any such formulas in the handbooks -- where did you get it?
Why are you doing this, Graham? There's a huge difference between
electroplating pennies with zinc--using safe household chemicals like
room temperature vinegar, as Tom described--and trying to use boiling
caustic and zinc dust!
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Ted Mooney
finishing.com
Brick, New Jersey |
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I have already performed the experiment once. It was in one of our
high school lab books, but the molarity for the sodium hydroxide was
not given. This is my problem. I assure you that I have been
performing it under careful supervision. I have been wearing safety
equipment, and the sodium hydroxide I'm using isn't strong enough to
be a very strong caustic. The zinc is mossy zinc, not zinc dust.
The plate just has not been very satisfactory. It should have
turned out silver and was instead a dull grey. I'm perplexed as to
why this is, and the only thing I can figure out is that the molarity
I used was wrong. Do you have any ideas at all?
Graham W
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I don't see the formula, or a similar one, in the
guidebooks, so I don't know. But I'm surprised that you were
able to get an immersion zinc plating onto steel.
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Ted Mooney
finishing.com
Brick, New Jersey |
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I was wondering how i can go about Electroplating a
diecast car? I've tried to find books on it with no luck.
Can you help me? I would like to Electroplate them gold and
chrome but need some help. Please let me know if you can
help. Thank you.
Jeff Griffith
Jeff:
There is plenty of info on that subject in the
books here; I suspect you
have been looking in general science project books, etc.,
rather than in industry books. But the real answer to your
question is that you can contact plating shops and have the
cars plated for you. Working with cyanide and hexavalent
chromium is no kind of hobby :-)
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Ted Mooney
finishing.com
Brick, New Jersey |
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I know exactly how to plate a copper penny with not only
silver but brass!
First you clean the penny really well and don't touch it.
Then you take about a gram of zinc shavings and mix that
with 20 ml of sodium hydroxide and boil it on low heat. Once
it starts to boil, drop in the penny and leave it there for
around 10 min. It will turn a silver color. Then carefully
take it out when it is totally silver (Still don't touch it)
and rinse it off and dry it out for a bit.Then comes the
cool part. You pick up the penny with tweezers and gently
heat it with a propane torch. Be careful not to heat it too
much or it will warp the penny. It about 5 seconds the penny
will turn a shiny gold color!
I did this in school today actually, and it worked great!
I'm only in 8th grade too, so this would make a good class
experiment.
Andy B
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