Was: Understanding Casting Shrinkage
What gives? Is casting to be viewed like sucking unfiltered Camel cigarettes? I will always advocate the safest and practical way to do things.
Todd and all others who are interested.
The danger of silicosis is real and potentially deadly. It is listed
as a known carcinogen on the MSDS and you will find a warning like
this one from R&R Ultravest on any package or directions from
Contains respirable crystalline silica (RCS). Do not breathe
dust. May cause delayed lung injury (silicosis, pneumoconiosis).
The IARC (International Agency for Research on Cancer) reports
(IARC Monograph 68) there is sufficient evidence in humans for
the carcinogenicity of inhaled crystalline silica in the forms of
quartz and cristobalite from inhaled crystalline silica in the
forms of quartz and cristobalite from occupational sources. The
NTP (National Toxicology Program) reports (Ninth Annual Report
on Carcinogens) that RCS is known to be a carcinogen based on
sufficient evidence from studies in humans indicating a causal
relationship between exposure to RCS and increased lung cancer
rates in workers exposed to crystalline silica dust. Follow OSHA
Safety and Health Standards for crystalline silica. See Material
Safety Data Sheet (MSDS) for detailed "
as one of many articles on the web about it also see
Investment is roughly 80 % silica in a much more finely ground state
than your typical construction worker gets exposed to. Breathing the
dust while mixing or quenching is almost impossible to avoid. Even
wearing N95 masks is rarely enough protection because a) most people
don’t know how to make sure the fit is correct and b) the most
dangerous dust stays in the air for long periods of time after mixing
or quenching. That dust settles on every surface of the shop and
every time you sweep or vacuum it up it gets redistributed into the
air. Your investing and quenching facilities need to be properly
ventilated and tested to make sure it is working properly
Google silicosis and you will be overwhelmed with on the
topic but little relating directly to jewelry trades. The there have
been several papers written and presented to the Santa Fe Symposium
on Jewelry Manufacturing and Technology about the silicosis problem,
contact Rio Grande for on which proceedings contain
on the topic.
Saying that you have been doing something that is unsafe for many
years and have not had any ill effects is very much like saying you
have been smoking for years and haven’t seen any ill effects from
it. You are not in a position to make that assessment in an objective
manner. By the time the effects of silicosis show up it is way too
late to do anything about it.
Todd, you need to get with some occupational health experts and
learn some more about this because you teach in a school and are both
responsible for the health of your students while in the classroom
and in providing them with safe practices to protect
them throughout their career.
Are those who can only research about technique the only real authority on jewelry making? I don't make this stuff up folks. If you are lucky enough to ever get into some of the industry casting facilities as I have you would see how it is done.
I was the production manager at a casting company where we did
hundreds of flasks per week, so I have just a little practical
experience in the field.
James Binnion Metal Arts