John Baymore on sat 24 oct 98
------------------
=3Csnip=3E
What health hazard? IMO, this is a really good idea=3B I have been
considering it for my old Paragon. The dealer suggested to me not to
use a whole blanket of the stuff, but just to use a =22collar=22 of it
between the lid and first ring - where you can see the light coming out
when the thing is on HIGH.
=3Cclip=3E
What health hazard............
Having the dusty blanket around makes it very likely that every time you
open and close the kiln you'll be getting tiny fibers airborne. Handling
the material for installation exposes you to fiber dust too.
Do a little research before using fiber products in this (or any)
application. Forewarned is forearmed. There are some indications that
refractory ceramic fiber (RCF) products are at least as carcinogenic when
breathed into the lungs as asbestos... or possibly more so. (Would you put
a fluffy layer of asbestos on top of the kiln =3Cg=3E?) Do the research and
then decide for yourself if you'll use it, and how you'll protect yourself
from it both in installation and in ongoing use.
I still use it......... VERY CAREFULLY. And I make sure my kiln clients
are made aware of the downside to this seemingly miraculous material.
If you are going to install it, think about soaking the fiber in a fine
spray of water before any significant handling (cutting, carrying, etc.).
Be particularly careful in removing a full roll of blanket from the
cardboard box it comes in...... the dry fiber has a tendency to exit the
box in a big POOF of heavily accumulated dust if it is just pulled out of
the box. To avoid this, cut the box carefully away from around the
fiber... then wet things down immediately. Wear a HEPA half face
respirator (check for correct FIT=21), put on a coverall over your clothing,
and put a scarf over your hair. After working with it, get out of the
outer clothes/scarf and wash them in lots of excess water. Wash yourself
off too.
If it is to be an insulating layer on the top of the lid, glue it onto the
firebrick lid with something like Sairmix 7, Greenpatch 421, Sairset, any
commercial refractory bonding mortar, ITC 100HT, or as a last ditch case
even sodium silicate (=2Asee bleow)...... then coat the exposed parts
including the edges with one of the many fiber coatings, ITC 100HT, thinned
Superpowerhouse mortar, or thinned Greenpatch 421 to seal the fiber surface
from dusting every time the lid is moved. At this point the layer will be
sort of like the consistency of a good thick crust of ice on a layer of
snow.
You could consider a fiber board here... but I really don't think the cost
is justified. Also possible is something called =22block=22 insulation, =
which
is pretty cheap and still light weight. Sort of like fiber board but
softer, has lower use temp, and is not made of RCF. (It still has some
breathing hazards.) However you'd have to do the heat transfer calculation
to see if the interface temperature generated (between cold face of IFB and
hot face of block) would exceed the maximum use temp for the specific block
used. Two and a half inches of (what is probably 2300) IFB doesn't have a
lot of insulating value...... passes a lot of heat through itself and with
insulation behind it can give a pretty high interface temp as cone 9 ish.
Ceramic fiber felt or paper is much better than blanket for kiln gasketing
in this regard... although it is not as compressible in that appliaction
and will not =22take up=22 as large irregularities in a seal area as 1/2 or =
1=22
blanket will. Should be more than adequate in this application unless your
kiln is near to death =3Cg=3E. These forms are more tightly constructed so
that they seem to =22dust=22 less than the blanket forms. They still will =
dust
some though.
BTW...... if you have a kiln that has metal parts on the top surface of the
lid... do not cover them with the fiber. It will raise the interface
temperature (the point between the outside of the original brick and the
bottom of the newly added fiber) to the point that the material will rust
out rapidly.
If you are installing it as a gasket, then you can't harden the outer
surface with a coating because it is the soft compressibility you want in
that application. Still, wet it for installation and glue it down.
Remember then, whenever you open and close the kiln it is possible (and
probable) that some fiber is getting airborne. You'll have to decide what
precautions you will want to take in that case. Good general dilution
ventilation in the kiln room would be a good minimum. Open the
kiln..........leave, and then wait a bit til the room air (potentially)
clears before loading or unloading.
Watch disturbing the gasket while loading or unloading too. You can make a
masque to cover the gasket out of a sheet of 1/8=22 luan plywood (with a jig
saw) that slips over the gasketed area for loading or unloading. Keeps
your arms and body from hitting the actual top edge of the kiln (and the
fiber).
Ceramic fiber felt or paper is much better than blanket for kiln gasketing
in this regard... although it is not as compressible in that appliaction
and will not =22take up=22 as large irregularities in a seal area. These =
forms
are more tightly constructed so that they seem to =22dust=22 less than the
blanket forms. They still will dust some though.
Contact Monona Rossol, Industrial Hygienist at ACTS, for info and reference
lists on this subject, as well as asking the suppliers for their MSDS and
safe installation guidelines on the products you are considering. Look at
a copy of =22Artist Beware=22 by Dr. Michael McCann. Read this stuff before
using the materials.
=2A(NOTE): This list of possible =22glues=22 is specific to THIS CASE, not =
to ANY
application of RCF to ANY IFB in ANY application. This is a very
non-critical application and most any =22sticky=22 stuff will work just fine=
in
this situation to hold the blanket in place. Use whatever you have laying
around. Other lamination situations are not necessarily so forgiving of
WHAT is used to glue the fiber product on with. Just wanted to make sure
noone thought this was a =22blanket=22 (pun intended) recommendation =
=3Cg=3E.
Best,
.....................john
PS: I thought that the new issue of Pottery Making Illustrated was VERY
remiss for not including more safety information than they did in the
article on making a drum type raku kiln lined with ceramic fiber. The
construction requires significant handling of the fiber with all the
cutting and folding, and this is a publication that is targeted
SPECIFICALLY at novice ceramists.
PPS: I see many people regularly use little bits of torn up blanket to
caulk up chinks in the doors of kilns. If you must do this (not
recommended)........ soak the little pieces of fiber in water and then
stuff them into the holes. When you are ready to unstack use a mister to
soak them again before you pull them out. Better yet..... just use some
junk paperclay. Or even just any refractory enough clay.
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
603-654-2752
JBaymore=40Compuserve.com
"Rafael Molina-Rodriguez (Rafael Molina-Rodriguez) (Rafael on mon 26 oct 98
------------------
John:
I share you concern about RCF. Here's some information from the =
=22FIBERFRAX
Warning=21=22 printed on their box:
=22Possible cancer hazard by inhalation=22
=22May be harmful if inhaled (Hazard depends on durationand level of =
exposure)=22
=22May be irritating to skin, eyes, and respiratory tract=22
=22This product contains a substance (refractory ceramic fiber) which has =
been
identified by the International Agency for Research on Cancer (IARC) as a
possible human carcinogen (group 2B)=22
=22Recommended Exposure guideline - 1 Fiber/cc. For airborne concentrations
greater than 1 fiber/cc use a NIOSH or MSHA approved air purifying =
respirator.
Provide engineering controls, where feasible, to keep airborne fiber =
exposure at
the lowest level attainable.=22
=22Workers should wear long-sleeve clothing, gloves, hat and eye protection =
to
prevent skin and eye contact. Wash thoroughly after handling. If not =
provided
with dispensable work clothes, avoid taking unwashed work clothes home. =
Wash
work clothes separately from other clothing. Rinse washing machine =
thoroughly
after use.=22
That's quite a disclaimer if you ask me=21 =3B-D I cringe when I see people=
use
this material with no precautions (and I get out of the area). The fiber I =
use
as arch insulation is buried under a coating mixture of sand and cement.
What really galls me is when I see studio artists or faculty using it =
recklessly
around unsuspecting bystanders. It is one thing to willingly subject =
oneself to
a hazardous material, but it is IMMORAL to expose someone else to it who is
agnostic of the dangers=21
Why don't more people use a rigidizer to cut down on the fibers. Thorpe =
sells a
product that will do this. They'll even add food coloring to the rigidizer =
so
you can see where it's been applied. Or perhaps people could use ITC to =
kill
two birds with one stone by rigidizing and increasing the heat efficiency of=
the
material.
I know there are people on the list who disagree with me on this subject. =
All I
can say is read the warning label printed on the box or the MSDS. The
information is there in plain English, clear and unambiguous.
Rafael
=3E=3E=3E John Baymore =3CJBaymore=40compuserve.com=3E 10/24/98 12:04pm =
=3E=3E=3E
----------------------------Original message----------------------------
------------------
=3Csnip=3E
What health hazard? IMO, this is a really good idea=3B I have been
considering it for my old Paragon. The dealer suggested to me not to
use a whole blanket of the stuff, but just to use a =22collar=22 of it
between the lid and first ring - where you can see the light coming out
when the thing is on HIGH.
=3Cclip=3E
What health hazard............
Having the dusty blanket around makes it very likely that every time you
open and close the kiln you'll be getting tiny fibers airborne. Handling
the material for installation exposes you to fiber dust too.
Do a little research before using fiber products in this (or any)
application. Forewarned is forearmed. There are some indications that
refractory ceramic fiber (RCF) products are at least as carcinogenic when
breathed into the lungs as asbestos... or possibly more so. (Would you put
a fluffy layer of asbestos on top of the kiln =3Cg=3E?) Do the research and
then decide for yourself if you'll use it, and how you'll protect yourself
from it both in installation and in ongoing use.
I still use it......... VERY CAREFULLY. And I make sure my kiln clients
are made aware of the downside to this seemingly miraculous material.
If you are going to install it, think about soaking the fiber in a fine
spray of water before any significant handling (cutting, carrying, etc.).
Be particularly careful in removing a full roll of blanket from the
cardboard box it comes in...... the dry fiber has a tendency to exit the
box in a big POOF of heavily accumulated dust if it is just pulled out of
the box. To avoid this, cut the box carefully away from around the
fiber... then wet things down immediately. Wear a HEPA half face
respirator (check for correct FIT=21), put on a coverall over your clothing,
and put a scarf over your hair. After working with it, get out of the
outer clothes/scarf and wash them in lots of excess water. Wash yourself
off too.
If it is to be an insulating layer on the top of the lid, glue it onto the
firebrick lid with something like Sairmix 7, Greenpatch 421, Sairset, any
commercial refractory bonding mortar, ITC 100HT, or as a last ditch case
even sodium silicate (=2Asee bleow)...... then coat the exposed parts
including the edges with one of the many fiber coatings, ITC 100HT, thinned
Superpowerhouse mortar, or thinned Greenpatch 421 to seal the fiber surface
from dusting every time the lid is moved. At this point the layer will be
sort of like the consistency of a good thick crust of ice on a layer of
snow.
You could consider a fiber board here... but I really don't think the cost
is justified. Also possible is something called =22block=22 insulation, =
which
is pretty cheap and still light weight. Sort of like fiber board but
softer, has lower use temp, and is not made of RCF. (It still has some
breathing hazards.) However you'd have to do the heat transfer calculation
to see if the interface temperature generated (between cold face of IFB and
hot face of block) would exceed the maximum use temp for the specific block
used. Two and a half inches of (what is probably 2300) IFB doesn't have a
lot of insulating value...... passes a lot of heat through itself and with
insulation behind it can give a pretty high interface temp as cone 9 ish.
Ceramic fiber felt or paper is much better than blanket for kiln gasketing
in this regard... although it is not as compressible in that appliaction
and will not =22take up=22 as large irregularities in a seal area as 1/2 or =
1=22
blanket will. Should be more than adequate in this application unless your
kiln is near to death =3Cg=3E. These forms are more tightly constructed so
that they seem to =22dust=22 less than the blanket forms. They still will =
dust
some though.
BTW...... if you have a kiln that has metal parts on the top surface of the
lid... do not cover them with the fiber. It will raise the interface
temperature (the point between the outside of the original brick and the
bottom of the newly added fiber) to the point that the material will rust
out rapidly.
If you are installing it as a gasket, then you can't harden the outer
surface with a coating because it is the soft compressibility you want in
that application. Still, wet it for installation and glue it down.
Remember then, whenever you open and close the kiln it is possible (and
probable) that some fiber is getting airborne. You'll have to decide what
precautions you will want to take in that case. Good general dilution
ventilation in the kiln room would be a good minimum. Open the
kiln..........leave, and then wait a bit til the room air (potentially)
clears before loading or unloading.
Watch disturbing the gasket while loading or unloading too. You can make a
masque to cover the gasket out of a sheet of 1/8=22 luan plywood (with a jig
saw) that slips over the gasketed area for loading or unloading. Keeps
your arms and body from hitting the actual top edge of the kiln (and the
fiber).
Ceramic fiber felt or paper is much better than blanket for kiln gasketing
in this regard... although it is not as compressible in that appliaction
and will not =22take up=22 as large irregularities in a seal area. These =
forms
are more tightly constructed so that they seem to =22dust=22 less than the
blanket forms. They still will dust some though.
Contact Monona Rossol, Industrial Hygienist at ACTS, for info and reference
lists on this subject, as well as asking the suppliers for their MSDS and
safe installation guidelines on the products you are considering. Look at
a copy of =22Artist Beware=22 by Dr. Michael McCann. Read this stuff before
using the materials.
=2A(NOTE): This list of possible =22glues=22 is specific to THIS CASE, not =
to ANY
application of RCF to ANY IFB in ANY application. This is a very
non-critical application and most any =22sticky=22 stuff will work just fine=
in
this situation to hold the blanket in place. Use whatever you have laying
around. Other lamination situations are not necessarily so forgiving of
WHAT is used to glue the fiber product on with. Just wanted to make sure
noone thought this was a =22blanket=22 (pun intended) recommendation =
=3Cg=3E.
Best,
.....................john
PS: I thought that the new issue of Pottery Making Illustrated was VERY
remiss for not including more safety information than they did in the
article on making a drum type raku kiln lined with ceramic fiber. The
construction requires significant handling of the fiber with all the
cutting and folding, and this is a publication that is targeted
SPECIFICALLY at novice ceramists.
PPS: I see many people regularly use little bits of torn up blanket to
caulk up chinks in the doors of kilns. If you must do this (not
recommended)........ soak the little pieces of fiber in water and then
stuff them into the holes. When you are ready to unstack use a mister to
soak them again before you pull them out. Better yet..... just use some
junk paperclay. Or even just any refractory enough clay.
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
603-654-2752
JBaymore=40Compuserve.com
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