Can anyone please help me, I am doing my thesis this year and need to
find out a few details about enamels, I have not been able to find
anything in books or over the internet.
Firstly: Why is there lead and/or heavy metals in enamels?
The closest answer, which is a geuss, that I can come to is that it
either lowers the melting temperature, or enhances the colours. But
I can’t go on that in my thesis.
Secondly: Are there any health risks involved in working with
leaded/meavy metal containing enamels?
Lastly: Is it possible to lower the melting point of glass, in order
to be used on precious metals?
If anyone can help me with any of the above topics, I will be
greatly appreciative!
Thank you very much for your time,
Claire
South Africa
I don’t work with traditional enamels, but since they are made from
glass and I do work with fused glass and special enamels made for
glass, let me suggest that if you don’t get an answer here, another
place to get some of the answers to these questions may be from a
glass blower who is familiar with making his/her own glass and deals
extensively with glass chemistry.
There are several boards on the InterNet for glass blowers, some of
whom deal with glass chemistry and can explain why different
materials are added to glass batch. There may be books on glass
chemistry, as well.
I can’t answer your first two questions to much more extent than you
have except to say that there is risk dealing with enamels, whether
or not they contain heavy metals. They are basically finely ground
glass and the long term hazard of inhaling glass dust is an
ultimately fatal disease known as silicosis.
Is it possible to lower the melting point of glass, in
order to be used on precious metals?
As for your last question, enamel is in fact ground up glass.
As well as being enamels being used on used on metals, metals can
also be used in glass, which is something that kiln-formers such as
myself do all of the time. We usually use metal foils because leaf
tends to burn out at fusing temperatures. Pieces much thicker than
foil can be problematic and caused breakage due to the vast
differences between the COE (Coefficient of expansion) of glass and
the COE of various metals.
By the way, there are lead free enamels that I use in my glass work.
I don’t think they’d work in traditional enameling applications,
though, since they aren’t really transparent.
May I suggest that you first approach your supervisor to help you
get started. That way you will be well informed of what is expected
from you.
If you have done that but are still uncomfortable with getting
started, then may I suggest that you begin your research by reading
many of the back issues of “Glass on Metal”, a publication from
Thompson Enamels? Mr. Thompson has written many articles that will
help you.
If you have not done so already, may I also suggest that you brouse
some first year chemistry and physics texts to become acquainted
with the chemical and physical properties of the materials used to
compose enamels? You will need to become familiar with such concepts
as “refractive index”, “coefficient of expansion”, transition
metals, oxides, hydroxides and salts.
In addition, you may also wish to consider reading introductory
texts on toxicology and ecology to address your questions regarding
the issue of lead toxicity. Concepts such as dose and biological
availability come to mind.
Finally, in writing an honours thesis you are expected to do your
own research by reading journals and texts. While asking questions
over the www is one approach to finding you have no way
of assessing its value. Academic books and articles in academic
journals are refereed, meaning that you can be assured that the
content is sound, especially when three or more articles on the same
subject say the same thing.
Your address suggests that you are writing from Zambia or RSA. If
that is true, then it is likely your are attending an academic
instituiton using the British model for tertiary education. It
follows then that you will be expected to defend your thesis during
an oral examination so that your supervisor and other examiners can
be assured that your knowledge of the subject matter covered in your
thesis is sound. At least that has been my experience.
Firstly: Why is there lead and/or heavy metals in enamels? The
closest answer, which is a geuss, that I can come to is that it
either lowers the melting temperature, or enhances the colours.
But I can't go on that in my thesis.
Why not? That’s the truth, it makes the colors prettier.
Secondly: Are there any health risks involved in working with
leaded/meavy metal containing enamels?
Uh? Are you kidding? Yes. Get some MSDS on leaded enamels. You can
also see brochures about the dangers of lead that are published by
the US government. They can be found on the website of the housing
department, whatever it’s called.
Lastly: Is it possible to lower the melting point of glass, in
order to be used on precious metals?
Huh? Perhaps reading up on glass would help you. Try warmglass.com
There are books on these topics. Newer enameling books have got to
mention it. There are at least two books with names like Artists
Safety Handbook that sound help you.
And buy Charles Lewton Brain’s book the Jewelry Workshop Safety
Report.
I just wanted to thank all those who answered my questions about
lead containing enamels, and lowering of glass melting temperatures.
It was my
first time on the orchid and I have found your answers to be very
informative and have opened new doors that I had previously
overlooked!
I have completed most of my research on the matter, and from next
week I shall be formally starting my experiments. However I am a
little worried about my kiln, as I’ll be working from home, most
probably in our conservatory. The kiln will be heated up to
temperatures ranging from 1050-1200 degrees centigrade, which is the
maximum temperature for the kiln. My problem comes in here, I have
read that ventilation is a very big issue when enamelling and working
in general with a kiln, I do not have an extractor fan at home, is it
possible to use an ordinary fan and have the windows and door open,
or shall I explore an alternative method?
I will be looking into getting the required safety equipment before
starting with these experiments, however I have come across some
contrasting (if that is the right word) on the correct
glasses (eye wear) to use. Although my lecturers have never deemed it
neccessary, I would like to use these glasses, as I plan to
specialise in enamelling, and thus want to prevent any chances of
getting glassblowers cataracts etc. Anyway, my research would
indicate that due to the amount of radiation and heat wave lengths
etc (I’m still new at THIS jargon) I should be using Didymium
glasses, however upon looking at a glassblowers website recently they
said that didymium glass would be pointless if used against the
above mentioned.
If anyone can clear this matter up for me I would appreciate your
responses. I have signed up to Thompson enamels forum, as I know
that they are more specialised on the matter, however they have not
yet activated my account. So to all the enamelists out there, please
help!
The basis for enameling depends I would say more on the properties
of glass than the metals so first study a bit on the history and
properties of glass. A related area is glass fusing a reference site
is:
Also study ceramics - particularly glazes.
Metals are included in glasses to provide special properties. Lead
for example makes a low melting point very fluid glass with a wide
temperature range but lead is considered potential a health hazard
and is undesirable in most modern glasses. Other elements are used to
provide color primarily.