Annealing - Revision history

Moto42 at 19:06, 12 June 2010

2010-06-12T19:06:56Z

Moto42: Just cleaning up the page a bit. No material removed; just shifted around a bit.

2010-06-10T02:51:37Z

Just cleaning up the page a bit. No material removed; just shifted around a bit.

Gnimelf at 18:32, 7 May 2007

2007-05-07T18:32:37Z

Gnimelf at 01:23, 27 April 2007

2007-04-27T01:23:28Z

Gnimelf at 00:54, 27 April 2007

2007-04-27T00:54:55Z

Gnimelf at 00:47, 27 April 2007

2007-04-27T00:47:44Z

Gnimelf at 00:46, 27 April 2007

2007-04-27T00:46:32Z

New page

'''Annealing''' is the process of relieving stress built up the a piece of glass as the result of uneven cooling. In modern times, electric kilns with digitally-controlled cooling programs are used to cool the glass at a sufficiently slow rate after the glass has been held at its annealing temperature for long enough that all stress has been relieved.

Previous to the advent of electric kilns, gas- or wood-fired kilns were used to anneal the glass. Such kilns required constant attention of someone to both monitor and control the temperature of the glass at any given time. In some cases, temperature of the glass was changed simply by incrementally moving the glass further from the heat source inside of the kiln (see photo.)

Unannealed glass must be considered unstable, as even subtle changes in environmental temperature or pressure could potentially trigger the latent stress in the glass to increase just enough to trigger cracking or, sometimes, even explosive shattering of the glass.

[[Image:http://www.wesleyfleming.com/murano_2005/DSCF2291.jpg]]

←Older revision		Revision as of 19:06, 12 June 2010
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	[[Image:gas-fired_kilns.jpg\|300px\|left\|thumb\|A wider view of the bank of kilns in this Murano studio. Although these kilns are now gas-fired, they were previously wood-fired. A fireplace is visible underneath each kiln - the exhaust (chimney) was directed up through the kilns to heat them. Photo credit: Wesley Fleming, 2004]]		[[Image:gas-fired_kilns.jpg\|300px\|left\|thumb\|A wider view of the bank of kilns in this Murano studio. Although these kilns are now gas-fired, they were previously wood-fired. A fireplace is visible underneath each kiln - the exhaust (chimney) was directed up through the kilns to heat them. Photo credit: Wesley Fleming, 2004]]
		+
		+	[[Category:Techniques]]
		+	[[Category:Basics]]

@@ Line 1: / Line 1: @@
 '''Annealing''' is the process of relieving stress built up the a piece of glass as the result of uneven cooling.  In modern times, electric kilns with digitally-controlled cooling programs are used to cool the glass at a sufficiently slow rate after the glass has been held at its annealing temperature for long enough that all stress has been relieved.
 Previous to the advent of electric kilns, gas- or wood-fired kilns were used to anneal the glass.  Such kilns required constant attention of someone to both monitor and control the temperature of the glass at any given time.  In some cases, temperature of the glass was changed simply by incrementally moving the glass further from the heat source inside of the kiln (see photo.)
@@ Line 5: / Line 5: @@
 Unannealed glass must be considered unstable, as even subtle changes in environmental temperature or pressure could potentially trigger the latent stress in the glass to increase just enough to trigger cracking or, sometimes, even explosive shattering of the glass.
-Following is a photo of goblets being annealed in a gas-fired kiln at a glassblowing studio in Murano, Italy.  The forked pole is used to pick goblets up and move them further away from the heat source inside of the kiln as the temperature evens out inside of each goblet.
+[[Image:Goblets_in_gas-fired_kiln.jpg|300px|left|thumb|goblets being annealed in a gas-fired kiln at a glassblowing studio in Murano, Italy.  The forked pole is used to pick goblets up and move them further away from the heat source inside of the kiln as the temperature evens out inside of each goblet. Photo credit: Wesley Fleming, 2004]]
-[[Image:Goblets_in_gas-fired_kiln.jpg]]
+[[Image:gas-fired_kilns.jpg|300px|left|thumb|A wider view of the bank of kilns in this Murano studio.  Although these kilns are now gas-fired, they were previously wood-fired.  A fireplace is visible underneath each kiln - the exhaust (chimney) was directed up through the kilns to heat them. Photo credit: Wesley Fleming, 2004]]
-−
-Photo credit: Wesley Fleming, 2004
-−
-This photo shows a wider view of the bank of kilns in this Murano studio.  Although these kilns are now gas-fired, they were previously wood-fired.  A fireplace is visible underneath each kiln - the exhaust (chimney) was directed up through the kilns to heat them.
-−
-[[Image:gas-fired_kilns.jpg]]
-−
 Photo credit: Wesley Fleming, 2004

@@ Line 7: / Line 7: @@
 Following is a photo of goblets being annealed in a gas-fired kiln at a glassblowing studio in Murano, Italy.  The forked pole is used to pick goblets up and move them further away from the heat source inside of the kiln as the temperature evens out inside of each goblet.
-[[Image:http://www.wesleyfleming.com/murano_2005/DSCF2291.jpg]]
+[[Image:Goblets_in_gas-fired_kiln.jpg]]
 Photo credit: Wesley Fleming, 2004
 This photo shows a wider view of the bank of kilns in this Murano studio.  Although these kilns are now gas-fired, they were previously wood-fired.  A fireplace is visible underneath each kiln - the exhaust (chimney) was directed up through the kilns to heat them.
-[[Image:http://www.wesleyfleming.com/murano_2005/DSCF2294.jpg]]
+[[Image:gas-fired_kilns.jpg]]
 Photo credit: Wesley Fleming, 2004

←Older revision		Revision as of 01:23, 27 April 2007
Line 8:		Line 8:

	[[Image:http://www.wesleyfleming.com/murano_2005/DSCF2291.jpg]]		[[Image:http://www.wesleyfleming.com/murano_2005/DSCF2291.jpg]]
		+	Photo credit: Wesley Fleming, 2004
		+
		+	This photo shows a wider view of the bank of kilns in this Murano studio. Although these kilns are now gas-fired, they were previously wood-fired. A fireplace is visible underneath each kiln - the exhaust (chimney) was directed up through the kilns to heat them.
		+
		+	[[Image:http://www.wesleyfleming.com/murano_2005/DSCF2294.jpg]]
	Photo credit: Wesley Fleming, 2004		Photo credit: Wesley Fleming, 2004

←Older revision		Revision as of 00:47, 27 April 2007
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	[[Image:http://www.wesleyfleming.com/murano_2005/DSCF2291.jpg]]		[[Image:http://www.wesleyfleming.com/murano_2005/DSCF2291.jpg]]
		+	Photo credit: Wesley Fleming, 2004