isaac
The following is taken from a section on conductivizing in an
electroforming book I am slowly working on:
There are quite a few methods of conductivising available to us.
In all of them perfect cleanliness before beginning is
essential.
Lacquers
By mixing very finely ground grease-free copper or silver flakes
or powders into thin lacquers or fast evaporating solvents one
can paint or spray on a conductive coating. For our purposes
spraying is far too wasteful so we usually brush the lacquers on.
Easiest to use (and most expensive) is ‘Silver Print’ or a
similar fine silver powder in a lacquer solution. This is painted
on and let dry. The solvent is often Butyl Acetate (major
ventilation requirement and potential health hazard). What we use
is most often a silver lacquer used for touching up printed
circuits and fine electrical connections. The copper lacquers
often need some thinning prior to use. For almost all
conductivising this method will be the best for us to use.
Nickel Print which is a nickel powder in solution is an
inexpensive alternative that appears to work very well.
Graphite
“Electro-typers grease free flakes” may be brushed onto the
article, the excess washed off in slow running cold water and
then the article plated. There is also a spray-on graphite
coating (mixed with adhesive already) available which may be of
some use in certain situations. I have used a ‘dry graphite
spray’ from the automotive store, it worked eventually but began
with a spotty plating.
For Plastics
One may mix “electrotypers copper flakes” or powder into the
solvent for the plastic in question and then plate or spray it
on. Bronze powders can be used in a similar manner.
Another method is to immerse the plastic in it’s solvent and
then roll it in a mixture of copper powders and crease-free
graphite flakes. When dry the excess is brushed off.
For Waxes
One may follow the same basic procedures as for plastics, except
that when casting wax into a rubber mold one may dust the mold
heavily with conductive materials prior to casting it. If done
correctly this will conduct electricity well enough for
electro-deposition to take place. The brush on lacquers remain
the easiest and fastest treatment.
There are some conductive waxes and plastics available, but they
are hard to find and are rather expensive compared to the
lacquers. They may fit some particular situation perfectly
though.
It is also possible to shellac the object and dust it or to
place gold or silver foils over it. The foil method dates from a
time when very skilled craftsmen were available and metal powders
could not be as finely ground. It is very expensive and time
consuming but there may be a time when it could be used for its
decorative effect on the inside.
Most industrial methods involve chemical silvering of the
object. This has some advantages but for us it is too
complicated. Using the silvering methods one may electrodeposit
on glass and ceramics. This is the same method as is used for
resilvering mirrors. It is possible to do it on a small scale
but the reasons for doing so would have to be good in order to go
to the trouble. I refer you to Linick, The Jewellers Workshop
Practices.
Amalgums may also be made up and used but these are again a
rather old-fashioned and a dangerous method.
hope this helps
Charles
Brain Press
Box 1624, Ste M, Calgary, Alberta, T2P 2L7, Canada
Tel: 403-263-3955 Fax: 403-283-9053 Email: @Charles_Lewton-Brain
Metals info download web site: Learning Center - Ganoksin Jewelry Making Community
Product descriptions: http://www.ganoksin.com/kosana/brain/brain.htm
Links list hosted at the Metal Web News:
http://tbr.state.tn.us/~wgray/jewelry/jewelry-link.html