Tom at Hutchtel.net on tue 22 nov 05
Jesse
I'm not talking about frozen water....and actually frozen water is less
dense than liquid water...ice floats. My point was that clay, when cold,
gets significantly stiffer, far more so than the slight increase in density
that Ivor pointed out. I doubt the clay/water mix is getting more
dense....it is the same amount of water, same amount of clay and the same
volume. Something's going on in the mix. Perhaps the electrical bonds get
greater at cold temps.
Now please explain why chilled clay, not frozen, gets stiffer.
Tom Wirt
----- Original Message -----
From: "jesse hull"
Subject: Re: heating pug mill/expanding water?
> Tom,
> Water certainly gets "thicker" when chilled...
> "expand" or "densify" would be better terms. Look at
> a new Wisconsin road after just a couple winters. -Or
> water pipes that burst in the cold.
> Keep in mind that water only expands when in a liquid
> state. The colder it gets, the more it expands -right
> up until it freezes completely. Ice actually
> contracts just a hair as it gets colder.
> Anything containing water would certainly get stiffer,
> -including clay.
jesse hull on tue 22 nov 05
Tom,
Water certainly gets "thicker" when chilled...
"expand" or "densify" would be better terms. Look at
a new Wisconsin road after just a couple winters. -Or
water pipes that burst in the cold.
Keep in mind that water only expands when in a liquid
state. The colder it gets, the more it expands -right
up until it freezes completely. Ice actually
contracts just a hair as it gets colder.
Anything containing water would certainly get stiffer,
-including clay.
In response to: "Why does wetted clay get stiffer when
it is chilled...softer when heated? Water doesn't get
thicker when chilled."
jesse hull on wed 23 nov 05
Ahhhh...
Thanks Phil, very informative. It's funny, no matter
how much you read/ research, sometimes the ol'
wivestales and the like get stuck up there.
I'd always thought that frozen pipes were a result of
ice forming in "pockets" and the water trapped in
between expanding and resulting in the bursting. I
could have sworn my science teacher had said that
water expands the most just around 39deg.F. I'll go
read more into it.
Ok, - getting OT, but it's still interesting...
~jesse.
In response to:
Hi Jessie, all...
>
>
> Ummmmmm, actually, "No"...not quite as that...
>
> Water will expand only very slightly as it is
warmed.
>
> It will wish to expand into Steam, ultimately, once
heated to or
above it's
> boiling
> point...or whatever it's boiling point may be at
some given
atmospheric or
> other enclosing pressure or constraint.
>
> Water occupies less volume as it is cooled, also,
but only very
slightly, of
> course.
pdp1@EARTHLINK.NET on wed 23 nov 05
Hi Jessie, all...
Ummmmmm, actually, "No"...not quite as that...
Water will expand only very slightly as it is warmed.
It will wish to expand into Steam, ultimately, once heated to or above it's
boiling
point...or whatever it's boiling point may be at some given atmospheric or
other enclosing pressure or constraint.
Water occupies less volume as it is cooled, also, but only very slightly, of
course.
At the moment of freezing, it expands as "Ice"...not anylonger as Water
per-se.
Ice, I believe stays the same as for it's volume at whatever range of
temperature of coldness it can exist at.
A given volume of Water when just below it's boiling point, will occupy
very slightly less volume when chilled to just above it's freezing
point...rather than that water expands as it becomes cooler.
Water Pipes in Wintery conditions, may appear to 'burst' once their interior
Water has frozen, and hence for that interior Ice to expand, to split open
the
pipes or their joins, so that as it thaws later, the liquid Water under
pressure from the local Water Company's pressurised distribution system,
leaks under pressure from these openings...it is not because the Pipes burst
from an expansion of cooling or chilled Water.
Viscocity-wise, I do not believe Water can be demonstrated to 'thicken' when
chilled, or at least not enough to be other than some extremely minute
amount, of interest to Science certainly, but not likely to ever be
noticable to anyone otherwise or to be of practical import.
At least this is my understanding...
For most things, Viscocity increases as their temperature lessens, or
decreases as their temperature increases, but I do not believe this is so
for Water.
Phil
el ve
----- Original Message -----
From: "jesse hull"
Subject: Re: heating pug mill/expanding water?
> Tom,
> Water certainly gets "thicker" when chilled...
> "expand" or "densify" would be better terms. Look at
> a new Wisconsin road after just a couple winters. -Or
> water pipes that burst in the cold.
> Keep in mind that water only expands when in a liquid
> state. The colder it gets, the more it expands -right
> up until it freezes completely. Ice actually
> contracts just a hair as it gets colder.
> Anything containing water would certainly get stiffer,
> -including clay.
>
> In response to: "Why does wetted clay get stiffer when
> it is chilled...softer when heated? Water doesn't get
> thicker when chilled."
Jim Kasper on wed 23 nov 05
Hi Phil,
A slight expansion on your expalanation. Water which freezes as 0 (zero) centigrade, has its maximum density at 4 degrees centigrade. This has the effect of circulating the water in fresh water lakes as they approach freezing. (This last tidbit is vaguely remembered from childhood science class, subject to correction)
For reference: http://www.simetric.co.uk/si_water.htm
Regards,
Jim
>
> From: pdp1@EARTHLINK.NET
> Date: 2005/11/23 Wed AM 03:51:50 EST
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Re: heating pug mill/expanding water?
>
> Hi Jessie, all...
>
>
> Ummmmmm, actually, "No"...not quite as that...
>
> Water will expand only very slightly as it is warmed.
>
> It will wish to expand into Steam, ultimately, once heated to or above it's
> boiling
> point...or whatever it's boiling point may be at some given atmospheric or
> other enclosing pressure or constraint.
>
> Water occupies less volume as it is cooled, also, but only very slightly, of
> course.
>
> At the moment of freezing, it expands as "Ice"...not anylonger as Water
> per-se.
>
> Ice, I believe stays the same as for it's volume at whatever range of
> temperature of coldness it can exist at.
>
> A given volume of Water when just below it's boiling point, will occupy
> very slightly less volume when chilled to just above it's freezing
> point...rather than that water expands as it becomes cooler.
>
> Water Pipes in Wintery conditions, may appear to 'burst' once their interior
> Water has frozen, and hence for that interior Ice to expand, to split open
> the
> pipes or their joins, so that as it thaws later, the liquid Water under
> pressure from the local Water Company's pressurised distribution system,
> leaks under pressure from these openings...it is not because the Pipes burst
> from an expansion of cooling or chilled Water.
>
> Viscocity-wise, I do not believe Water can be demonstrated to 'thicken' when
> chilled, or at least not enough to be other than some extremely minute
> amount, of interest to Science certainly, but not likely to ever be
> noticable to anyone otherwise or to be of practical import.
>
> At least this is my understanding...
>
> For most things, Viscocity increases as their temperature lessens, or
> decreases as their temperature increases, but I do not believe this is so
> for Water.
>
>
> Phil
> el ve
>
>
> ----- Original Message -----
> From: "jesse hull"
> Subject: Re: heating pug mill/expanding water?
>
>
> > Tom,
> > Water certainly gets "thicker" when chilled...
> > "expand" or "densify" would be better terms. Look at
> > a new Wisconsin road after just a couple winters. -Or
> > water pipes that burst in the cold.
> > Keep in mind that water only expands when in a liquid
> > state. The colder it gets, the more it expands -right
> > up until it freezes completely. Ice actually
> > contracts just a hair as it gets colder.
> > Anything containing water would certainly get stiffer,
> > -including clay.
> >
> > In response to: "Why does wetted clay get stiffer when
> > it is chilled...softer when heated? Water doesn't get
> > thicker when chilled."
>
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Linda Ferzoco on wed 23 nov 05
There are other solids/semi-solids that are harder when cold: saturated fats, sauces made with starches, gelatin (denatured collagen) and others I'm sure.
What happens to Silly Putty in the fridge?
So where are the physical chemists out there to explain these phenomena to us?
Linda
Pacifica, California
Snail Scott on thu 24 nov 05
At 10:39 PM 11/22/2005 -0600, you wrote:
>Now please explain why chilled clay, not frozen, gets stiffer.
I have understood that chilled water becomes more dense
until about 4=BAC (just above its freezing point). This is=20
the phenomenon that allows lake water to 'turn over' -
when the lower, warmer layers rise to the top because=20
the top layers (near the winter air) cool off, become=20
denser, and drop down.=20
Whether this phenomenon demonstrates a sufficient change=20
in density to be detectable in clay is perhaps debatable,=20
but density changes in water do apparently occur.
-Snail
Ivor and Olive Lewis on fri 25 nov 05
Dear Linda Ferzoco,
If I were to suggest the impossible no one would believe what I might =
write about the nature of Water in Plastic Clay. But an answer can be =
found if you are a diligent researcher.
I have found, via a practical test of rolling clay into cylinders and =
freezing them at about minus 14 Celsius( that is 7 F or 25 below) that =
some water changes into ice. But the greater volume of that plastic clay =
become a brittle solid. Fracture have the same hall marks of a steel or =
other metallic bar when it is broken. When allowed re-heat to room =
temperature plasticity can be restored.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
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