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Below are questions
asked by enamelers and the appropriate responses. If you
have a question to ask of our experts, please fill out the form
located on this page.
Q. I
have a PMC Kiln and want to use it for the enameling. One
of the temperatures I often use is 1460, which may be too
low. I can set it to other temps. What experience
has anyone had with doing enameling in a PMC
kiln? P.W.
A. The
problem with PMC is it's porosity. The areas to receive
enamel should be compressed by chasing, planishing, burnishing,
engraving or tumbled with steel shot.
The piece should be designed to be
enameled, meaning that there is a place for the enamel to start
and stop. The metal should have uniformity, not thick and
thin, due to expansion/contraction in relation to the rate of
cooling.
With silver, 1400ƒF, silver salts go
into the solution of the glass and act as a colorant, especially
at higher temperatures.
If the PMC kiln can reach and hold a
temperature, it should be able to be used to enamel.
Q. When
doing torch enameling, do I need to use that pasty, blue stuff
on the back of my metal? Is this material necessary to use
when torch enameling one side of the
metal? N.
A. That
'pasty blue stuff' is now cream colored, and is called
Scalex. Scalex is used to reduce and/or eliminate red and
black copper oxide. To use or not to use is up to you.
Q. I
generally make champleve enamel pieces using both the lead free
and original Thompson lead enamels. I am considering
having some of the pieces gold plated after the final polish,
but have heard that some enamels do not work well with the
plating process. Do you have any advice on this
topic?
A. Some
enamels might not be acid resistant. Check with a plating
company - find one with experience plating enameled
pieces. Many of our readers are in the commercial end and
plate production work all the time. You should have no
problem finding one.
Q. We
make hand-crafted replica pot stills and would like to coat the
interior of one to use as a whiskey decanter. The problem
is that there is only a 40mm hole for access. Is it
possible to pour some kind of enamel inside to coat the item and
then drain off the excess? The vessel holds approx. 8
litres of whiskey and would have to meet trading
standards. A.S.
A. Your
question is: Is it possible to coat the interior of a pot
still? The answer is yes. However, the 'still' would
have to be constructed with becoming enameled in mind.
A 40mm hole is sufficient, however,
drying the liquid form enamel is very tricky. A furnace of
appropriate size would be needed. The project would
require experience.
Q. I am
going to be working in copper enamel with the hope of making
fine jewelry and art pieces. Is it possible to find a
suitable kiln for less than $200? What type/make of
kiln do experts recommend? I've worked with the small
glass topped one my mother had from the
1950's. C.B.
A. The
furnace should be suitable for the size of the pieces you're
going to make. It should meet your production needs.
Most who do enamel art pieces grow out of their first furnace;
those who do jewelry may never have that happen. Since you
have already used the hotplate type, consider how it fits your
future. You can always fire a small piece in a large
furnace, but you can't fire a large piece in a small one.
The furnace is your major tool and
should not be your limitation. Are furnaces available for
$200 or less? Yes. Check classified ads for used
furnaces. Experts look for furnaces that will meet their
needs. I have two furnaces in my home studio - the small
one will take a 6 inch piece comfortably. The large one
will take a 14 inch piece.
Q. I am
curious, is it possible to put cold rolled steel or stainless
inside blown glass? T.O.
A. Yes,
however 'cold rolled', 'stainless' and 'blown glass' are general
terms. You would need to know the coefficients of
expansion, both the metal and the glass, to see if they were compatible.
Q. Who
invented enameling? Why did they invent it, and when did
everyone start using it for work and
business? E.P.
A. The
earliest known to us is the 13th century B.C. in Cyprus,
however, glass dates to the Peloponnesian Wars. Why did
they invent it? It was a discovery. After it was
discovered, it was used to please the King, and I am not talking
about Elvis...
Q. Has
anyone a technique for removing lead solder from silver so that
it can then be re-enameled? B.
A. Burn
it off, then use a scraper. LEAD FUMES ARE VERY DANGEROUS.
Q. I
have a question about enameling with gold; what is the lowest
karat you can use and is it possible to solder a gold cut and
pierced piece to a fine silver piece and enamel that? C.D.
A. The
answer is yes, gold and silver can be enameled when soldered
together. The higher karats work best.
What is of most importance is the
structure of the piece and is it designed to be enameled.
Q. Will
brass take enamel? I am making a wheel of brass 1/4"
rod. I am thinking I would like to have it enameled.
Is it possible to do this? Would it take multiple firings
to enamel all surfaces. J.V.
A. You
need to know the alloy proportion of the metal. How is the
wheel constructed? Liquid form enamel may be used.
Number of firings depend on the shape and your skill level.
Q. I'm
trying to re-create medieval champleve enamel panels such as
those created in Limoges, and can't find information on how
thick of copper was generally used.
Help? G.T.
A. The
depth of cut for the cells is variable depending on the
workpiece. For gold, engraving can be very shallow.
Thickness of metal varied, as each piece would be hammered and
cut to shape by the metalsmith. The thickness of early
Limoges champleve plaques (copper) was up to about 1.6mm
(0.063"), equal to modern Browne & Sharpe standard
gauge 14.
Q. I am
a student at the University of Central Lancashire in
England. I'm studying surface pattern and I'm really
interested in enameling. I've only really used copper so
far, but I'm moving into silver and gold shortly. I am
writing my dissertation about enameling, and this is my
question:
Do contemporary enamelists have
constraints on the shape, size and form of their work, and do
different techniques work better with different shapes, sizes or
forms? I am sure your opinion to my question will be very
useful to me. Thank you for taking time out to answer it!
A. The
constraints on size would be determined by the size of the
equipment - furnace size; equipment to move work in and out of
furnace. Some sculpture that has been enameled has been
15' in length.
There are some shapes that do not
enamel well, i.e. a long, thin, narrow strip. Also, if a
'V' were cut out of metal, the 'crotch' of the 'V' may crack due
to unequal expansion rates. A piece of metal that is thick
in one area, thin in another, and continuously covered in enamel
will crack where the thick and thin meet due to unequal
expansion rates (enamel expands and contracts with heating and
cooling).
Q. Can
anyone tell me what the proper procedure is for cleaning steel
to allow base enamel to fuse properly to the surface (the
sources I've read all ignore this and only tell how to do this
with copper).
A. The
metal should be free of grease, oil, and/or rust. The
metal could be sand blasted or heated to 800ƒF to burn off
grease/oil - then pickled in Sparex #1 if any rust is
present.
Q. I
recently purchased a batch of old lead bearing enamels - all of
which, although old, are in excellent condition. Among
them is a container of 108 Transparent Forsythia, which a friend
advised that I immediately dispose of as hazardous
material. She said it is radioactive and was removed from
circulation because it caused cancer. Is she
correct?? I never heard this about 108 Transparent
Forsythia manufactured by Thompson, but do remember a problem
with some enamel from Japan. Please advise if it is safe
for me to use the Forsythia. I will not be using it for
any items to be worn, but had planned to use it for a wall
piece. Thanks for your advice. A.R.
A. The manufacture of
Thompson's 108 Forsythia was not discontinued (back in the
'70's) due to radioactivity. Spent uranium oxide was used
to impart the yellow color to this enamel. Government
regulations were so involved and ordering procedures so
complicated that it became unfeasible to continue using spent
uranium oxide.
Nuclear Regulatory commission staff
concluded that normal use of enamel jewelry using spent uranium
as a colorant (108) does not constitute an immediate or
significant health hazard.
Calculations indicate that continued
use of a large piece of jewelry - such as a pendant - with the
enamel surface in direct contact with the skin for a period of
50 hours per week for a year would result in a radiation dose
about 1/4 of that which would be allowed for the skin of workers
in the nuclear industry under current NRC regulations. If
the enameled surfaces are not in direct contact with the skin,
the dose would be considerably less.
The staff believes, however, that use
of the slightly radioactive jewelry does constitute an
unnecessary exposure to radiation based on the principle that
any exposure to radiation should be avoided.
SOURCE: The United States
Nuclear Regulatory Commission, Office of Public Affairs Region
III, 799 Roosevelt Rd., Glen Ellyn, IL 60137, News
Announcement 83-05, February 3, 1983. (The above taken
from Glass on Metal, Vol. 2, No. 2, pp. 19 & 20.)
Q.
I
want to purchase a used enameling kiln and possibly some tools
to get started. Do you happen to know of any out there
that are available? I am checking web sites and
classifieds as well as our colleges here. I prefer to stay
away from a heavily used studio kiln as the high use and
wear. Any leads or information would be helpful! - B.F.
A. A good kiln would
be one in which the interior fire brick is in good
condition. The kiln floor especially should not have 'pot
holes'. Some cracks in the fire brick are normal after
use, but you would not want any fire brick pieces loose and
looking like they might fall out. If it looks to be in
pretty good shape, it probably is. It is probably wise to
find out if you can obtain replacement elements and switch,
(i.e. is the manufacturer still in business?) If not, you
might want to write down pertinent information about the kiln
(volts, amps, interior dimensions, etc.) and call Paragon
Industries to see if they could make replacement elements for
your no-longer-being-manufactured kiln. If, when buying a used
kiln, you are bartering about price, this would be a good reason
for requesting a reduced cost.
Q. What
adhesive material is preferred for sticking frit to vertical
surfaces (bottles and glasses) for firing? I don't want
the glass frit particles to fall off before the melting temp has
been reached.
A. Particle size is an
important factor to firing on vertical surfaces. Klyr Fire
is recommended (available from Thompson Enamel), which would
hold powders (finer than granular sugar) onto a vertical surface
- but anything larger than a fine powder would probably not
work. TE
Q. I made
metal flowers from cut flat nails. I would like to add
color using the enamel process. Can I add enamels to
red-hot steel?
A. I assume nails are high
carbon. Iron with .02 to .04% carbon requires an enamel
ground coat first. Higher % carbon is not considered
enamelable, however, I have worked with blacksmiths, so give it
a try. To hot sift, heat nail to a bright red heat.
Wire brush off scale quickly and sift on an enamel before it
loses color. Then instantly reheat to gloss the
enamel. Work quickly. Reheating after having cooled
will cause failure. HBH
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