Brian Crocker on sun 20 jun 99
Dear CLAYARTERS following the thread raised a few days ago re, a
window in a Kiln side or lid. It was suggested [Bruce Girrell] that a Fuzed
silica should be used, I followed this and eventualy found that,
CROWN TECHNIGLASS a division of Crown Scientific Pty. Ltd. in Moorebank
New South Wales, Australia have the equipment to make such a thing, and I
am assured that the same product can be purchaced from CROWN in most,
"first world countries". The Fax I recieved is as follows.
Re; Quartz Window,
Size: 200x200x5mm thick
Quantity one only: 1 only
Price each: $431.oo
Delivery: 4 weeks on 50% deposit
Delivery per order $15.oo
Telephone [International] (612)9602 9800
Fax [international] (612)9821 1817
Contact: John Skene.
I was informed that each size can be made to order, I nominated 200 x 200
because it is a size through which most of an average interior could be
seen. Larger and smaller windows can be made and the cubic centimetres
determine the price. Rectangular shapes also made. The smaller the lower the
cost.
An insulated door would be necessary to reduce radiated heat loss and
such devices are often used in Industry.
I hope this is of some help.
Kind regards to all. Brian C..
Brian Crocker.
4 Erica Street,
Tea Tree Gully 5091,
South Australia. [e.mail] crocker@dove.net.au
The Driest State that's a little wetter now.
Jonathan Pennington on mon 17 dec 01
* Martin Howard [011217 18:05]:
> > made of *glass* strips. >
> These were of thick mica sheets.
> Surely they would be OK for kiln spy holes and not expensive.
The story in my Geology department (undoubtedly fabricated by the damn
Russians :-) was that the name of low iron (semi-clear) mica:
"Muscovite," came from the fact that people in western Russia and
thereabouts used much of it for furnace glass, due to the incredibly
large crystals found around the Urals (Mica crystals the size of a
man... a very large man). Many micas won't melt at any temp you can
very easily achieve- least not at surface pressure. Good stuff.
However, I wonder- I know it was a joke, but it's still interesting-
about the efficiency of having a great deal of a clear/semi-clear
material as a kiln- like the comment about a clear kiln. Heat and
light are so tied, that having that much "light" escape the internal
area of the kiln seems the same as having that much "energy"
escaping. The loss would probably be minimal with a single peephole,
but I wouldn't want to have any more area open to energy loss than I
have to, simply because I'm trying to keep as much in as possible. Of
course, having the mica keep the heat in for times when you are
*removing* the peep hole to look- in otherwords, using them both-
that's an idea I could be interested in.
-J
--
Jonathan Pennington | jwpennin@bellsouth.net
"There are no pots, there is only clay." -original
"It's hard to take life too seriously
when you realize yours is a joke." -also original
Bruce and Lynne Girrell on fri 21 dec 01
Jeremy McLeod wrote asking why there couldn't be a way to put a window in a
kiln.
Diffusion furnaces, used in the manufacture of semiconductors, have windows
made of fused silica and operate at temperatures similar to potters' kilns.
Whether they are affordable and where you can get them, I'm afraid I don't
know, but it's a direction to start.
Bruce and Lynne Girrell
Finally taking a vacation, currently near Yuma, AZ where we can almost see
Joyce ITM if we look hard enough across the river. Passed through San
Ildefonso and Santa Clara on our way out here. We actually bought a Santa
Clara pot (from Toni Roller, daughter of Margaret Tafoya)! It's our
Christmas present to ourselves.
Hated to miss out on that horsehair thread, but we've been on the road.
Hard to keep up with Clayart.
Steve Mills on sat 22 dec 01
In message , Bruce and Lynne Girrell writes
>Jeremy McLeod wrote asking why there couldn't be a way to put a window in a
>kiln.
>
>Diffusion furnaces, used in the manufacture of semiconductors, have windows
>made of fused silica and operate at temperatures similar to potters' kilns.
>Whether they are affordable and where you can get them, I'm afraid I don't
>know, but it's a direction to start.
For years my Mother had a Coke Stove in her house with a window in it
made of *glass* strips. When one got broken she'd give me the bits to
make windows in place of spy holes in my Gas Kiln. I only replaced them
when they got ingrained with soot to the point where I couldn't see
through 'em any more! The current generation of wood-burning stoves have
similar windows in them.
Just a thought.
Steve
--
Steve Mills
Bath
UK
Jose A. Velez on sun 23 dec 01
For whatever is worth, industrial boilers do have windows to observe the =
flame paterns in the furnace. Although the furnaces do not reach the =
temperatures experienced in kilns the same principles might apply. =
These windows are made of a very thick glas protected by a metal disk =
that is rotated out of the way by a manual mechanism, air purges are =
used to keep the glass cool and clean during the observation period. =
Maybe a high refractory ceramic could be used to protect the glass =
instead of metal.
Jose A. Velez
Martin Howard on sun 23 dec 01
made of *glass* strips. >
These were of thick mica sheets.
Surely they would be OK for kiln spy holes and not expensive.
Martin Howard
Webbs Cottage Pottery
Woolpits Road, Great Saling
BRAINTREE, Essex CM7 5DZ
01371 850 423
martin@webbscottage.co.uk
http://www.webbscottage.co.uk
Updated 13/12/01
GlassyClass on sun 23 dec 01
Was talking with one of the glass reps at church today, he said that Schott
glass makes a product that is a mixture of ceramic and glass that would do
it(although he did not know of any product that would go to 2300 F), a
product called Zerodur. So guess that most glasses are going to be for less
than cone 10.
http://www.schott.com/lithotec/english/products/zerodur.html
Seems the key is zero expansion at high heat or low cold.
Found others also:
http://www.ohara-inc.co.jp/ohara_e/n2_00/hinmoku/clearcer/f3_18.htm
CLEARCERAM®-Z
http://www.skan.co.uk/heat.htm
Robax®
http://www.abrisa.com/glass.asp
Ceramic Glasses are good up to 1500 degrees F (see our Physical Properties
Comparison Chart). Schott Robax®, Corning Pyroceram® and NEG's Neoceram® are
virtually interchangeable brands available. This glass has a slight amber
tint and orange peel mottling on the surface. Most commonly used in
fireplace applications due to extreme heat and termal shock resistance. See
our Chart U.V. Blocking - Robax Data Sheet for more information. Oralon® is
our brand name for the lighting version of this glass. In lighting, Oralon
is often used where extreme heat and/or U.V. Blocking is a concern (see our
U.V. Comparison Chart).
Quartz glass includes GE124 Quartz® and Corning Vycor® (see our Quartz
Comparison Data Sheet), and can withstand temperatures up to 2000 degrees F
(see our Physical Properties Comparison Chart).
V Y C O R ®
ViscositySoftening Pt.1530°C 2786°F
Annealing Pt1020°C 1868°F
Strain Pt.890°C 1634°F
Sincerely,
Bud Britt
Tustin, CA, USA
glassyclass@worldnet.att.net
http://www.homestead.com/glassyclass/
----- Original Message -----
From: "Steve Mills"
Sent: Saturday, December 22, 2001 3:42 PM
Subject: Re: Windows in kilns
> In message , Bruce and Lynne Girrell writes
> >Jeremy McLeod wrote asking why there couldn't be a way to put a window in
a
> >kiln.
> >
> >Diffusion furnaces, used in the manufacture of semiconductors, have
windows
> >made of fused silica and operate at temperatures similar to potters'
kilns.
> >Whether they are affordable and where you can get them, I'm afraid I
don't
> >know, but it's a direction to start.
> For years my Mother had a Coke Stove in her house with a window in it
> made of *glass* strips. When one got broken she'd give me the bits to
> make windows in place of spy holes in my Gas Kiln. I only replaced them
> when they got ingrained with soot to the point where I couldn't see
> through 'em any more! The current generation of wood-burning stoves have
> similar windows in them.
>
> Just a thought.
>
> Steve
> --
> Steve Mills
> Bath
> UK
>
Philip Poburka on sun 23 dec 01
Dear Martin,
Would not the Isinglass or 'Mica' sheet melt in the radiance of those
temperatures a Kiln may be expected to reach?
What ought we suppose the melting point of 'Mica' to be, or would probably
be for a given thickness?
Anyone know?
Phil
Las Vegas...
----- Original Message -----
From: "Martin Howard"
To:
Sent: Sunday, December 23, 2001 1:57 PM
Subject: Windows in kilns
> > made of *glass* strips. >
> These were of thick mica sheets.
> Surely they would be OK for kiln spy holes and not expensive.
>
> Martin Howard
> Webbs Cottage Pottery
> Woolpits Road, Great Saling
> BRAINTREE, Essex CM7 5DZ
> 01371 850 423
> martin@webbscottage.co.uk
> http://www.webbscottage.co.uk
> Updated 13/12/01
>
>
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Michael Banks on sat 12 jan 02
Depends on the purity of the mica, Philip.
Pure white mica (muscovite) does not melt below cone 10. How transparent it
will still be is moot, because it's structure is disturbed somewhat by the
loss of it's hydroxyl groups at red heat.
Pure muscovite has only potash present, and less than 0.5% soda in the
alkali sites. If there is significant soda present (paragonite solid
solution), it will cause it to fuse at lower temperatures, because of the
soda-potash-silica eutectic. Likewise, lithian muscovites and lepidolite
(lithium mica) melt as low as cone 6 because of their high lithium and
fluorine content (not to mention significant rubidium and caesium).
Michael Banks,
Nelson,
NZ
----- Original Message -----
From: Philip Poburka wrote:
> Would not the Isinglass or 'Mica' sheet melt in the radiance of those
> temperatures a Kiln may be expected to reach?
>
> What ought we suppose the melting point of 'Mica' to be, or would probably
> be for a given thickness?
>
> Anyone know?
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