Transite/Heat Resistant Surface

Jewelry Discussion
1

Hi All! I thought I would pass this on to anybody who has been
searching for transite or firebricks. Cutter Northern are great
people to deal with. They were not aware of the large number of
jewelers/metalsmiths that require heat resistant surfaces.

Cutter Northern Refractories

They provide excellent firebricks and non-asbestos transite cement
board. What is transite? It is an amazing heat resistant material
that is perfect when soldering and enameling. You can lay extremely
hot pieces of metal right on the board, and never have to worry
about burning the underneath surface. Transite used to be made of
concrete and asbestos. Once the asbestos was discovered to be
hazardous, locating this perfect heat resistant material was
impossible. While picking up my firebricks for the school, I
discovered that have re-engineered transite and made it completely
safe for the studio.

Transite HT comes in 1/4 inch to 2 inch thickness and can be custom
cut.

If you want to find out more about this product, or obtain a piece
for your studio (which I highly recommend), contact Cheryl
DeLongchamps cchamps@cutternorthern.com

They are located at:

10 Hancock St.
Woburn, MA  781/938-8998

Karen Christians
M E T A L W E R X
10 Walnut St.
Woburn, MA 01801
Phone:781/937-3532
Fax: 781/937-3955
http://www.metalwerx.com/
Accredited Jewelry Instruction

2

I discovered that have re-engineered transite and made it completely
safe for the studio.

G’day Karen - I seem to be forever playing the Devil’s advocate -
it’s not a role I enjoy, but … if the material you are talking
about is Transite HT then it’s a calcium silicate insulating board -
here’s a quote from the MSDS issued May 3 2002:

"Primary Routes of Entry: Via respirable dust to the lungs and
respiratory system and via coarse dust and particulate to the eyes.

Primary Target Organs: Lungs, respiratory system and eyes.

Potential Health Effects:

Inhalation: Long term overexposure to respirable crystalline silica
dust may cause permanent and irreversible lung damage including
silicosis.

Skin Contact: Possible dryness or irritation resulting from long
term exposures to product dust.

Eye Contact: A mechanical irritant which can cause moderate to
severe eye irritation.

Ingestion: Non-hazardous when ingested. Potentially a mild irritant
to the GI tract if excessive quantity is ingested.

Medical Conditions Aggravated by ExposuRe: Pre-existing chronic
upper respiratory and lung diseases such as, but not limited to,
bronchitis, emphysema and asthma.

Carcinogenicity: This product contains crystalline silica which is
classified as a class 1, human carcinogen by IARC, as a suspect
carcinogen by NTP and as a possible select carcinogen by OSHA."

All of which just means that you don’t saw it, grind it, file it or
otherwise disturb the surface, not that you don’t use it!

Just that you are aware that there are potential hazards and use it
accordingly.

MSDS sheet is heRe: http://www.bnzmaterials.com/msds/msdsht.html

cheers
Al Heywood

3

Hi Karen, We chose many years ago, to leave the transite alone… I
went with ceramic tiles for all 6 soldering benches. You have the
inconvenience of the grout seams, but use the biggest tiles to
reduce them.

We use various soldering boards, bricks, and fixtures on top anyway.
The tile merely provides a fireproof surface in case you get off of,
or away from your main work area. It’s also impermeable to pickles,
fluxes, and boric acid. Washes right off.

I also put a low extruded aluminum corner mold “rim” at the very
front of the soldering stations - to keep the pesky, red hot, round
pieces from rolling off a fixture and into your lap!

Brian P. Marshall

4

I’d like to comment on Allen Heywood’s quote from the MSDS for
Transite HT. First, it is generous to take the time and trouble to
pass on the warning-- I, myself, have grave doubts about anything
being reengineered to be “completely safe and non toxic”. Often,
this actually means that the maker has switched from a known
hazardous material to a similar one that hasn’t been tested yet.
Cynical, but true. But I also want to point out that the danger of
silicosis from a product like this (“Inhalation: Long term
overexposure to respirable crystalline silica dust may cause
permanent and irreversible lung damage including silicosis”) is
likely truly negligible, unless perhaps you work where it is made,
and powder is in the air all the time. I read up on silicosis during
my years as a potter.

I’m not knowledgeable about classes of carcinogens, but if " This
product contains crystalline silica which is classified as a class
1, human carcinogen by IARC, as a suspect carcinogen by NTP and as a
possible select carcinogen by OSHA" is the same thing that would be
said about clay, which also contains silica, then it can’t mean
much. I’ve never heard of a case of cancer attributed to
silica–only lung disease, and that takes a lot of exposure.

I agree with Allen’s conclusion-- “All of which just means that you
don’t saw it, grind it, file it or otherwise disturb the surface
[too much], not that you don’t use it! Just that you are aware that
there are potential hazards and use it accordingly”. My point is that
you still have to read between the lines.

–Noel

5 
    I'm not knowledgeable about classes of carcinogens, but if "
This product contains crystalline silica which is classified as a
class 1, human carcinogen by IARC, as a suspect carcinogen by NTP
and as a possible select carcinogen by OSHA" is the same thing that
would be said about clay, which also contains silica, then it can't
mean much. I've never heard of a case of cancer attributed to silica
-- only lung disease, and that takes a *lot* of exposure.

Noel, the study here:
http://www.cdc.gov/niosh/pdfs/crystal-silica.pdf is a rigorous review
of previous long-term studies which focussed on silicosis. Until this
recent (1996) review it was generally assumed that lung cancer
resulting from long-term exposure to crystalline silica was
statistically insignificant. The review demonstrates that this is not
the case.

My concerns are not so much for older people, who should have the
nous to protect themselves, but for younger people - children often -
who are reliant on the “knowledge” and common sense of their
teachers. An uncomfortably high number of contributors to internet
forums are short on both commodities. One of the problems facing
groups such as this is filtering out the mis- since
Orchid is basically an unmoderated platform the filtering has to take
place after comments are posted rather than before.

cheers

Allan Heywood

6

It is right and proper to be concerned about health issues in the
studio but you must look at more than whether it is just has a
exposure warning on the MSDS you must also asses the way in which
you are exposed to the dangerous material and the amount of exposure
to determine what steps if any that need to be taken to deal with
your exposure to the hazardous material. The about the
dangers of silica is readily available from a variety of sources
including the MSDS that should come with hazardous materials in the
US. In the case of the transite board being discussed here there is
a very low chance of exposure to the dangerous (sub 10 micron in
size particles) if you don’t cut or grind it. Silica is a problem
like many other dusts when the particle size is so small that your
lungs cant get rid of it. We are exposed to much greater silica
danger when we work with casting investment which has lots of these
micro fine particles that get into the air when we mix and quench
the investment. BTW it is not noted on the MSDS but if you smoke and
are exposed to silica dusts the chance of respiratory damage from
the silica doubles.

Jim

7 
        I'm not knowledgeable about classes of carcinogens, but if
" This product contains crystalline silica which is classified as a
class 1, human carcinogen by IARC, as a suspect carcinogen by NTP
and as a possible select carcinogen by OSHA" is the same thing that
would be said about clay, which also contains silica, then it can't
mean much. I've never heard of a case of cancer attributed to
silica -- only lung disease, and that takes a *lot* of exposure.

No. The same thing could not be said about clay.

There is a huge difference between freshly prepared ground silica
and the kind in sediments (clay ?), beach sand, and the like.

Freshly ground silica particles are a very serious health hazard
when respired, but “aged” particles that have been lying around in
sediments or soil dust are not. People who spend their lives
breathing dust or beach snad generally do not get silicosis or lung
cancer, even though all samples of these materials contain very small
particles 10 microns or less in diameter (the most hazardous
particle size range). But miners and others exposed to freshly made
particles do get silicosis and may die from it. There are several
scientific theories about why freshly ground silica should be so
dangerous whereas “aged” silica particles that have been lying around
in sediments or on the surface of the ground are not. One is that
there are exposed reaction sites on the fresh surfaces that affect
lung tissue, but not on the aged surfaces, whose reactions sites have
long been occupied by various molecules. None of the theories has
been satisfactorily tested nor gained wide acceptance among the
experts.

The clay most artists use is not made by grinding up silica and its
other constituents (?) and therefore is not dangerous enough to
require an MSDS.

But if any clay, investment, or other material you use comes with an
MSDS that warns about silicosis, pay very careful attention to it.

Dian Deevey

8

A colleague and friend of me in Belgium is a lung specialist and a
jewelry maker in his free time. He is very worried about the
relationship between investment (which contains silica) and lung
cancer. He absolutely refuses to use the stuff and subsitutes it with
raku clay. I have never tried it, but perhaps someone else is using
raku clay as investment here. I would be interested to learn about
the results. As for the silica, I believe that Dian is right, but I
am not an expert in the matter. Regards, Will

9

Dian- Thank you for this clarification. Could it be that "old"
particles have worn smoother? In any case, it is interesting
Always better safe than sorry-- I’m a great believer in
wearing protection of appropriate type Even though few of those on
this site are likely to be working much with clay, I feel compelled
to mention that potters do occasionaslly get silicosis, and that clay
is often freshly ground, to make minerals blend better and have
smaller particle size. I’m pretty sure clays have MSDS’s. My original
point was that these materials take fairly massive, long-term
(chronic) exposure, and I would be surprised if it were a real hazard
to use a material like Transite, even if you cut it to size
occasionally, or inadvertantly break or drill into it once in a
while. The trick is to have the right priorities and perspective,
since zero risk is impossible. --Noel