Talbott on tue 10 jun 97
As Ron suggested I placed a mug -cone 10 stoneware glazed inside and out-
(a second) into the freezer for 24 hours and then pour boiling water into
the mug... That is exactly what I did... Results the mug after about 10
seconds cracked around the bottom... I did the same test yesterday but
with only 20 min of freezer time and the mug survived... I can't help but
feel this is an extreme test. I think that it might be possible to design
a mug that would withstand this test but this is on the excessive side of
things... Our mugs do stand up to pouring boiling hot water into a room
temp mug with no problems... But just the same I feel that anyone should
preheat a mug before pouring boiling hot water into it and certainly even
more so the same applies for teapots. If you care anything about a piece
you will use it in the manner it is intended to be used... Pottery can be
broken if you try hard enough and I don't want to encourage my customers to
be unwise users of pottery... I think that customers buying mugs or any
other items of pottery should have a PROPER CARE AND USE brochure included
along with the sales receipt. This will probably eliminate 90% of the
problems associated with any returns... Marshall
1ST ANNUAL CLAYARTERS' GALLERY - NAPLES, MAINE (Summer 1997)
http://fmc.utm.edu/~dmcbeth/cag/naples.htm
Celia & Marshall Talbott, Pottery By Celia, Route 114, P O Box 4116,
Naples, Maine 04055-4116,(207)693-6100 voice and fax,(call first)
WBS Live Chat Room, Sat Nites 10 PM EDT, Private Room: Clayarters
JULIE ATWOOD on wed 11 jun 97
> But just the same I feel that anyone should
> preheat a mug before pouring boiling hot water into it and certainly even
> more so the same applies for teapots. If you care anything about a piece
> you will use it in the manner it is intended to be used...
I'm sorry if I have this backwards, but from what I remember, we make
pottery so people can do what they ordinarily do with a bit of added
beauty to the function. I DON'T remember people going out of their way
to do normal tasks because the pottery cannot withstand everyday use.
How many people do YOU know pre-heat their coffee cups? I don't know one
single person. Of COURSE no one pre-heats their coffee cups. You buy
the mug to pour the coffee in...hot, of course.
No wonder people buy mass-produced items with no beauty. People today
are entirely too busy to worry about having to PRE HEAT coffee mugs,
teapots, platters, and the like. Now, I would tell anyone who took a mug
staight from the freezer and poured boiling water in it it was their own
darn fault it cracked, because of course, that's not expected of ANY food
item...no one puts a glass in the freezer, then pours a boiling hot drink
into it. But no one pre heats their glasses either!
It's ridiculous to assume normal, busy people are going to buy pottery
they have to pre heat to use. If they do buy it, it's going to be
sitting on a shelf collecting dust because, "I don't have time to use
that mug, I need to preheat it, I'll just use this other plain black
slipcast mug from Wal-Mart for now".
*shaking her head* Like I said, maybe I'm just BACKWARDS...but I doubt it.
Julie in Seattle
Jennifer Boyer on wed 11 jun 97
Hi Marshall,
I don't think it's reasonable to expect customers to preheat mugs before
adding water. I think it gives hand made pottery a bad name if you have to
tell them to coddle it too much. And there are plenty of clay bodies out
there that will stand up to boiling water. Do you reduce your kiln?
Sometimes heavy reduction can set up thermal shock problems in clay,
especially clay with alot of iron and silica in it. Just a thought.
Jennifer in VT
jboyer@plainfield.bypass.com(NEW ADDRESS!!!!)
> But just the same I feel that anyone should
>preheat a mug before pouring boiling hot water into it and certainly even
>more so the same applies for teapots. If you care anything about a piece
>you will use it in the manner it is intended to be used... Pottery can be
>broken if you try hard enough and I don't want to encourage my customers to
>be unwise users of pottery... I think that customers buying mugs or any
>other items of pottery should have a PROPER CARE AND USE brochure included
>along with the sales receipt. This will probably eliminate 90% of the
>problems associated with any returns... Marshall
>
>
Liz Willoughby on wed 11 jun 97
Hello Marshall,
I have used the 24 hour freezer test on mugs and even teapots, followed by
pouring in boiling water. I do this periodically to find out if I have a
possible dunting problem or a problem with glaze/body fit. It is a way of
speeding up the process that your pots go through with continued use. I do
use a porcelainous clay body with very little iron, which is an advantage
as far as cristabalite formation goes. I am in no way a scientific potter,
but I do care about the pots that I put out there on the market. I would
suggest having clay and glaze expansion tests done. Also, even if you have
been using the same clay and glaze over the years, materials do change,
which can result in dunting or stress problems that can cause cracking. I
wholeheartedly agree with having a brochure printed up on the proper use of
functional pottery, but if there is a problem it may not show up for weeks.
Regards, Liz . p.s. Just a thought, try doing the 24 hour freezer test
on the same mug you left in the freezer for 20 min.
----------------------------Original message----------------------------
>As Ron suggested I placed a mug -cone 10 stoneware glazed inside and out-
>(a second) into the freezer for 24 hours and then pour boiling water into
>the mug... That is exactly what I did... Results the mug after about 10
>seconds cracked around the bottom... I did the same test yesterday but
>with only 20 min of freezer time and the mug survived... I can't help but
>feel this is an extreme test. I think that it might be possible to design
>a mug that would withstand this test but this is on the excessive side of
>things... Our mugs do stand up to pouring boiling hot water into a room
>temp mug with no problems... But just the same I feel that anyone should
>preheat a mug before pouring boiling hot water into it and certainly even
>more so the same applies for teapots. If you care anything about a piece
>you will use it in the manner it is intended to be used... Pottery can be
>broken if you try hard enough and I don't want to encourage my customers to
>be unwise users of pottery... I think that customers buying mugs or any
>other items of pottery should have a PROPER CARE AND USE brochure included
>along with the sales receipt. This will probably eliminate 90% of the
>problems associated with any returns... Marshall
>
> 1ST ANNUAL CLAYARTERS' GALLERY - NAPLES, MAINE (Summer 1997)
> http://fmc.utm.edu/~dmcbeth/cag/naples.htm
>
> Celia & Marshall Talbott, Pottery By Celia, Route 114, P O Box 4116,
> Naples, Maine 04055-4116,(207)693-6100 voice and fax,(call first)
> WBS Live Chat Room, Sat Nites 10 PM EDT, Private Room: Clayarters
Liz Willoughby
R.R. 1
Grafton, Ontario
K0K 2G0
e-mail lizwill@cyberion.ca
Ron Roy on wed 11 jun 97
How to answer this in a way that the information will useful. When I am
developng glazes I always do the freezing then boiling water test - about
10 times. All of the pottery I make can withstand this test. What you have
experienced is a sure sign there are stresses built into your ware and at
least some of it will show up in your ware eventually. The fact that this
mug was glazed inside and out (with the same glaze) indicates there is a
very serious fit problem. The reason the mug cracked around the bottom is
because there is usually more glaze in that area.
The problem is a glaze that winds up too big for the clay. There are
reasons for all that and they are resolvable. The glaze can be made to
contract more on cooling and/or the body can be reformulated to avoid
cristobalite build up. The worst bodies are those with some iron and less
than 10% feldspar (as someone else pointed out.)
If ovenware is your game it better be able to pass this test - the big
problem with cristobalite - it goes through it's reversible expansion/
contraction at ovenware temperatures.
>As Ron suggested I placed a mug -cone 10 stoneware glazed inside and out-
>(a second) into the freezer for 24 hours and then pour boiling water into
>the mug... That is exactly what I did... Results the mug after about 10
>seconds cracked around the bottom... I did the same test yesterday but
>with only 20 min of freezer time and the mug survived... I can't help but
>feel this is an extreme test.
Ron Roy
Toronto, Canada
Evenings, call 416 439 2621
Fax, 416 438 7849
Studio: 416-752-7862.
Email ronroy@astral.magic.ca
Home page http://digitalfire.com/education/ronroy.htm
Talbott on thu 12 jun 97
Liz... Thanks for the reply and that is what I did... the SAME mug that
survived 20 minutes in the freezer that was immediately filled with
boiling water (as in bubbling) did NOT survive the 24 hours in the freezer
and then immediately filled with boiling water... I would suggest that a
few of you should likewise try the same test on a "second" of course and
see how your wares do... Do any of you have a mug that will survive the 24
hours in the freezer and then fill immediately with boiling water?... If
so please share your cone 9/10 stoneware claybody recipe... I do fire in
reduction... YES.. I do agree that it is not practical to preheat a mug
for ordinary use... and is not really necessary either... Marshall
>----------------------------Original message----------------------------
>Hello Marshall,
>I have used the 24 hour freezer test on mugs and even teapots, followed by
>pouring in boiling water. I do this periodically to find out if I have a
>possible dunting problem or a problem with glaze/body fit. It is a way of
>speeding up the process that your pots go through with continued use. I do
>use a porcelainous clay body with very little iron, which is an advantage
>as far as cristabalite formation goes. I am in no way a scientific potter,
>but I do care about the pots that I put out there on the market. I would
>suggest having clay and glaze expansion tests done. Also, even if you have
>been using the same clay and glaze over the years, materials do change,
>which can result in dunting or stress problems that can cause cracking. I
>wholeheartedly agree with having a brochure printed up on the proper use of
>functional pottery, but if there is a problem it may not show up for weeks.
>Regards, Liz . p.s. Just a thought, try doing the 24 hour freezer test
>on the same mug you left in the freezer for 20 min.
1ST ANNUAL CLAYARTERS' GALLERY - NAPLES, MAINE (Summer 1997)
http://fmc.utm.edu/~dmcbeth/cag/naples.htm
Celia & Marshall Talbott, Pottery By Celia, Route 114, P O Box 4116,
Naples, Maine 04055-4116,(207)693-6100 voice and fax,(call first)
WBS Live Chat Room, Sat Nites 10 PM EDT, Private Room: Clayarters
Talbott on thu 12 jun 97
Ron... We are not intending for our pottery to be used for oven-ware or
flame-ware... only that it is microwaveable and dishwasher safe,,,, And
will last for years under ordinary use... So what to do from this point to
increase the thermal shock qualities to pass the test of 24 hours in
freezer and fill with boiling water?
>----------------------------Original message----------------------------
>How to answer this in a way that the information will useful. When I am
>developng glazes I always do the freezing then boiling water test - about
>10 times. All of the pottery I make can withstand this test. What you have
>experienced is a sure sign there are stresses built into your ware and at
>least some of it will show up in your ware eventually. The fact that this
>mug was glazed inside and out (with the same glaze) indicates there is a
>very serious fit problem. The reason the mug cracked around the bottom is
>because there is usually more glaze in that area.
>
>The problem is a glaze that winds up too big for the clay. There are
>reasons for all that and they are resolvable. The glaze can be made to
>contract more on cooling and/or the body can be reformulated to avoid
>cristobalite build up. The worst bodies are those with some iron and less
>than 10% feldspar (as someone else pointed out.)
>
>If ovenware is your game it better be able to pass this test - the big
>problem with cristobalite - it goes through it's reversible expansion/
>contraction at ovenware temperatures.
>
>
>
>>As Ron suggested I placed a mug -cone 10 stoneware glazed inside and out-
>>(a second) into the freezer for 24 hours and then pour boiling water into
>>the mug... That is exactly what I did... Results the mug after about 10
>>seconds cracked around the bottom... I did the same test yesterday but
>>with only 20 min of freezer time and the mug survived... I can't help but
>>feel this is an extreme test.
>
>Ron Roy
>Toronto, Canada
>Evenings, call 416 439 2621
>Fax, 416 438 7849
>Studio: 416-752-7862.
>Email ronroy@astral.magic.ca
>Home page http://digitalfire.com/education/ronroy.htm
1ST ANNUAL CLAYARTERS' GALLERY - NAPLES, MAINE (Summer 1997)
http://fmc.utm.edu/~dmcbeth/cag/naples.htm
Celia & Marshall Talbott, Pottery By Celia, Route 114, P O Box 4116,
Naples, Maine 04055-4116,(207)693-6100 voice and fax,(call first)
WBS Live Chat Room, Sat Nites 10 PM EDT, Private Room: Clayarters
Talbott on thu 12 jun 97
Julie... I suggest that you reread the post and distinguish between HOT
and BOILING... Yes, I microwave water to the boiling point in our mugs
with no problem and I can pour boiling water into a cold mug with no
problems but NOT into a FROZEN mug (24 hrs in the freezer). Try this
thermal shock acid test yourself and see how your wares stand up... I
would strongly suggest using a "second"... Guess I would be really
interested to know if this is a realistic expectation of pottery to stand
up to Ron's test.. Best Wishes... Marshall
>----------------------------Original message----------------------------
>> But just the same I feel that anyone should
>> preheat a mug before pouring boiling hot water into it and certainly even
>> more so the same applies for teapots. If you care anything about a piece
>> you will use it in the manner it is intended to be used...
>
>I'm sorry if I have this backwards, but from what I remember, we make
>pottery so people can do what they ordinarily do with a bit of added
>beauty to the function. I DON'T remember people going out of their way
>to do normal tasks because the pottery cannot withstand everyday use.
>
>How many people do YOU know pre-heat their coffee cups? I don't know one
>single person. Of COURSE no one pre-heats their coffee cups. You buy
>the mug to pour the coffee in...hot, of course.
>
>No wonder people buy mass-produced items with no beauty. People today
>are entirely too busy to worry about having to PRE HEAT coffee mugs,
>teapots, platters, and the like. Now, I would tell anyone who took a mug
>staight from the freezer and poured boiling water in it it was their own
>darn fault it cracked, because of course, that's not expected of ANY food
>item...no one puts a glass in the freezer, then pours a boiling hot drink
>into it. But no one pre heats their glasses either!
>
>It's ridiculous to assume normal, busy people are going to buy pottery
>they have to pre heat to use. If they do buy it, it's going to be
>sitting on a shelf collecting dust because, "I don't have time to use
>that mug, I need to preheat it, I'll just use this other plain black
>slipcast mug from Wal-Mart for now".
>
>*shaking her head* Like I said, maybe I'm just BACKWARDS...but I doubt it.
>
> Julie in Seattle
1ST ANNUAL CLAYARTERS' GALLERY - NAPLES, MAINE (Summer 1997)
http://fmc.utm.edu/~dmcbeth/cag/naples.htm
Celia & Marshall Talbott, Pottery By Celia, Route 114, P O Box 4116,
Naples, Maine 04055-4116,(207)693-6100 voice and fax,(call first)
WBS Live Chat Room, Sat Nites 10 PM EDT, Private Room: Clayarters
Molly Gorger on thu 12 jun 97
JULIE ATWOOD wrote:
>
> --------------------------Original message--------------------------
> How many people do YOU know pre-heat their coffee cups? I don't know one
> single person. Of COURSE no one pre-heats their coffee cups. You buy
> the mug to pour the coffee in...hot, of course.
>
Julie,
I too would want my cup to hold up pouring hot coffee straight into
it.....but I do prefer to pre-heat my cup and so did my Dad. It seems
to keep the coffee hotter longer. I don't always do this but it is my
preference. Just wanted to let you know....some of us do heat our mugs
first....And our teapots and our coffee air pots etc.
So now you know of two of us! Try it...it works...
Breathe deep and smile!
~~Molly
Don Jones on thu 12 jun 97
>
>How many people do YOU know pre-heat their coffee cups? I don't know one
>single person. Of COURSE no one pre-heats their coffee cups. You buy
>the mug to pour the coffee in...hot, of course.
>
I'm going to nit-pick here. Lots of people do. Pouring coffee into a cold
mug on a cold day will cool the coffee down too quickly and after a short
while the coffee is actually too cold to drink.
Don Jones
perfect in Albuquerque
Timothy Dean Malm on thu 12 jun 97
Greetings
The discussion of pre-heating of mugs reminds me of a visit made to the
Brahmah Museum of Tea and Coffee in London. While there I noted that
pre-heating of ones chosen teapot with boiling water then pouring it out
prior to actually brewing tea is a required act according to the "Rules"
for brewing a "proper tea".
Tim Malm
Seattle
On Wed, 11 Jun 1997, Jennifer Boyer wrote:
> ----------------------------Original message----------------------------
> Hi Marshall,
> I don't think it's reasonable to expect customers to preheat mugs before
> adding water. I think it gives hand made pottery a bad name if you have to
> tell them to coddle it too much. And there are plenty of clay bodies out
> there that will stand up to boiling water. Do you reduce your kiln?
> Sometimes heavy reduction can set up thermal shock problems in clay,
> especially clay with alot of iron and silica in it. Just a thought.
> Jennifer in VT
> jboyer@plainfield.bypass.com(NEW ADDRESS!!!!)
>
>
>
> > But just the same I feel that anyone should
> >preheat a mug before pouring boiling hot water into it and certainly even
> >more so the same applies for teapots. If you care anything about a piece
> >you will use it in the manner it is intended to be used... Pottery can be
> >broken if you try hard enough and I don't want to encourage my customers to
> >be unwise users of pottery... I think that customers buying mugs or any
> >other items of pottery should have a PROPER CARE AND USE brochure included
> >along with the sales receipt. This will probably eliminate 90% of the
> >problems associated with any returns... Marshall
> >
> >
>
Gavin Stairs on fri 13 jun 97
At 07:16 PM 12/06/97 EDT, Tim Malm wrote:
.... > While there I noted that
>pre-heating of ones chosen teapot with boiling water then pouring it out
>prior to actually brewing tea is a required act according to the "Rules"
>for brewing a "proper tea".
Gee, Tim, I'm so glad you noticed that. As a tea lover who sometimes finds
himself in the outer darkness of tea which is America, I have many times
suffered through the tortures of tea made by the uninitiated. At
McDonald's and almost everywhere, I am served a cup of hot water, set to
cool with the tea bag cosy in its sachet beside it! This is worse than the
British habit of serving breakfast toast in a little cooling rack,
guaranteed to provide you with cold, hard toast upon which cold, hard
butter has no chance of melting. But worst of all is tea made in, or from,
water heated (not even boiled) in a coffee urn. I have had this in hotels
that should have known better.
But then, you need to have good tea to be able to benefit from proper
brewing. Give yourself a treat sometime. Find some really good tea (no,
not Earl Grey, nor Breakfast Brambleberry: just some first leaf Orange
Pekoe, or some Darjeeling, or a good green tea). Then find a nice pot.
Boil some water. When it has come to a full, rolling boil, (don't wait),
pour some of it into the pot, swoosh it about, let it sit for a moment to
preheat the pot. Set the kettle back to heat to the boil again. Then dump
out the pot, put in some tea, pour on the boiling water, and wait a moment
or two. When the tea has had a chance to develop its flavour, but before
it becomes bitter, pour out a cup for yourself and a companion. Smell.
Taste. No lemon! No sugar! No milk! Just tea.
You will have noticed that there are several variables to play with: which
tea, which pot, how much tea, how long to steep. These you may play around
with for the rest of your life. Later you can investigate the lengthy
history of tea, the habits of the Chinese, the Indians, the English, the
Japanese. You can play with adulterants, like salt, sugar, fruit juices
and rinds, floral buds and essences, other leaves, essential oils, barks,
roots, seeds. After a few decades you may begin to appreciate what tea is
about. Then perhaps you will be like the grandmothers who complain when
you put the milk in After the tea instead of Before, and why can you not
properly Boil the water for the tea.
Enjoy, Gavin
=================================
Gavin Stairs
http://isis.physics.utoronto.ca/
Ron Roy on fri 13 jun 97
>----------------------------Original message----------------------------
>Ron... We are not intending for our pottery to be used for oven-ware or
>flame-ware... only that it is microwaveable and dishwasher safe,,,, And
>will last for years under ordinary use... So what to do from this point to
>increase the thermal shock qualities to pass the test of 24 hours in
>freezer and fill with boiling water?
Hi Marshal,
Send me the recipe for the glaze and the clay - don't worry about me using
or giving away your stuff - I do this for hundreds of potters evey year. It
is just a matter of finding where the glaze starts crazing and droping back
a bit. We should probably make a change to the body at the same time - tell
me how far down the cone is when you fire - top and bottom. I would be very
helpful fo I knew the overall shrinkage of your clay and the absorbancy
after the glaze fire.
Oh yes - I need to know what the glaze and clay look like fired and if
there are other things that need attention loke pin holing etc. so I can
try to fix them at the same time.
Ron Roy
Toronto, Canada
Evenings, call 416 439 2621
Fax, 416 438 7849
Studio: 416-752-7862.
Email ronroy@astral.magic.ca
Home page http://digitalfire.com/education/ronroy.htm
Russel Fouts on fri 13 jun 97
------------------
Molly,
=3E=3E I do prefer to pre-heat my cup and so did my Dad. It seems
to keep the coffee hotter longer. ...some of us do heat our mugs
first....And our teapots and our coffee air pots etc. =3C=3C
Pre-heating the teapot is one of the secrets to making =22proper=22 tea. You
only have to pour hot water into it though, then pour it out to do this.
Pre-heating mugs makes some sense as well, it should keep your coffee
hotter since the hot coffee doesn't have to waste energy to heat the mug.
(Marshall, you could use that angle to get people to pre-heat your mugs.)
For =22proper=22 tea:
- 1 pre-heated, Unglazed terracotta tea pot (never wash, just rinse=21)
- 1 spoon of good loose tea for each cup (your choice, but Earl Grey
tastes like Chanel =23 5 to me)
- 1 for the pot
- Pour BOILING water over the loose tea.
- Let steep
- Turn the pot to mix the tea a LITTLE
- Serve and enjoy
Russel
=21=5ENavFont02F02BD0007MGHHIBE4897
JULIE ATWOOD on fri 13 jun 97
OK OK OK...after SO many replies I've gotten pointing to pre heating
coffee mugs to prolong the warmth of the coffee, I say, great, wonderful,
but that wasn't my point. That's a point of preference.
As I said in a previous response just a moment ago, my post had to do
with the NECCESSITY of pre heating coffee mugs because they DIDN'T STAND
UP to pouring hot coffee in them at room temp or colder.
As for anyone that pre heats their mugs because they want their coffee
hotter longer, that's terrific, but that had nothing to do with my point. :)
Julie
NOTE: ANY REPLIES...to louie@eskimo.com
JATWOOD@OSCAR.CTC.EDU WILL NOT EXIST AS OF TOMORROW
On Thu, 12 Jun 1997, Don Jones wrote:
> ----------------------------Original message----------------------------
> >
> >How many people do YOU know pre-heat their coffee cups? I don't know one
> >single person. Of COURSE no one pre-heats their coffee cups. You buy
> >the mug to pour the coffee in...hot, of course.
> >
>
> I'm going to nit-pick here. Lots of people do. Pouring coffee into a cold
> mug on a cold day will cool the coffee down too quickly and after a short
> while the coffee is actually too cold to drink.
> Don Jones
> perfect in Albuquerque
>
Jennifer Boyer on sat 14 jun 97
Well,
I tried the freezing for 24 hours and then boiling water test on 4 of my
mugs, from my cupboard, so some were quite old. They sailed through with
flying colors. I use T-3 (fired to cone 10) from Sheffield Pottery in
Mass.
I've had a few thermal problem returns over the years, but most have
involved people baking cheese or meat, fatty things, so that the food is
not evenly spread in the pot. Once, the guy was baking cheese nacho's on a
dinner plate, with the cheese hitting the plate in random places. I return
these pots for free.
Take Care,
Jennifer in VT
>----------------------------Original message----------------------------
>Julie... I suggest that you reread the post and distinguish between HOT
>and BOILING... Yes, I microwave water to the boiling point in our mugs
>with no problem and I can pour boiling water into a cold mug with no
>problems but NOT into a FROZEN mug (24 hrs in the freezer). Try this
>thermal shock acid test yourself and see how your wares stand up... I
>would strongly suggest using a "second"... Guess I would be really
>interested to know if this is a realistic expectation of pottery to stand
>up to Ron's test.. Best Wishes... Marshall
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*
Jennifer Boyer
Thistle Hill Pottery
Montpelier, Vt. 05602
jboyer@plainfield.bypass.com
James Henry Gorman on sat 14 jun 97
Common sense tells you never pour boiling water on anything frozen!
^10 ox electric kiln ) fired cookware does much better in the ovens than
^10 gas or wood fired cookware,i have done both! ^10 ox mugs does not have to
be preheated to drink my Irish coffee in!
Jim
ps proper why to make tea! Find the south side of your home,find a sunny
spot!
get 1/2 gal mason jar/lid 4 family size tea bags fill jar /water add tea
bags!find that sunny spot again place the mason jar there! go make pots until
lunch,get
lunch +mug /ice/sugar/lemon find that sunny spot again! tea is ready remove
bags and pour into mug (do not pre heat mug) put chair in sunny spot so you
will
always be able to find it,sometimes it gets tough and a little tea and sun
will
always bring a smile
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