| MadSci Network: Chemistry |
Hi Ardelle!
It's hard to tell why your copperplating didn't work,
since you don't say HOW it failed.
If you just ended up with lots of black glop, then the current
was way too high. Low current creates bulk copper, but high
current creates microscopic "grass" made of copper filaments,
and this looks like black gelatine even though it's made of
copper metal. It falls right off the electrode.
Some companies use this process to make extremely black
coatings, far blacker than any paint (for use in space
telescopes, etc.)
An aquarium-sized tank is a huge project.
You might want to start out small, and do your
electroplating in a little cup of water, using
a D-cell battery or two. When you get it working
and learn how it behaves, you can then scale
everything up.
Twelve volts seems awfully high for an electroplating
tank. Something more like two volts is more common. Ideally,
when doing a big electroplating project like yours,
you should be adjusting the current
(the amperes) and not really caring so much what the
voltage is. To do this, you'd need an adjustable power supply
with a current meter. What current to use? I don't
know. It depends on the size of the object being plated.
Start low, and if the copper layers grow too slowly,
crank up the current higher. But if it's TOO high,
then the copper surface will become very rough, and if its
even higher, you'll grow the black glop stuff instead
of solid copper.
Rather than making black glop, did nothing happen
at all? If so, and if the object made of lead is coated
with dark grey lead-rust, the "rust" might prevent the
electroplating. You might first have to clean off
the Lead Oxide coating so that your object is silvery,
but I don't know of any safe way to do this.
Lead Oxide can give you lead poisoning, and the only
legal way to dispose of it is at the local dump in
the "toxics" section. Scraping it off might work,
if you use disposable gloves and tools, and wear a
sawdust mask. Never try to use sandpaper. The
powdered oxide will get all over everything, and
you'll literally have to hire a decontamination
company to clean up, so that everyone in your family
won't be slowly poisoned.
Mark K. says that electroplating works better if you
use sulphuric acid to raise the conductivity of
the water in your tank. You can get the acid at auto parts
stores. DANGER, IT CAN BURN YOUR SKIN. Or blind
you. Or start fires if spilled on paper or wood.
If you don't know the many safety procedures needed
for handling sulphuric acid, DON'T USE IT.
You could also try consulting the folks on this forum:
NEWSGROUP: REC.CRAFTS.METALWORKINGCertainly there will be hobbyists with lots of electroplating experience there. If you don't have a newsgroup browser, you can register with the free Dejanews service above, then post your questions on that forum.
http://www.deja.com/group/rec.crafts.metalworking
Other links about home electroplating projects:
http://www.finishing.com/0000-0199/064.html
http://www.finishing.com/0000-0199/196.html
http://www.finishing.com/Letters/index.html
Try the links in the MadSci Library for more information on Chemistry.