Logan Johnson on wed 14 oct 09
Hey Vince ,
Here is the BBC story I read & in it "the experts" say (at the bottom of th=
=3D
e article)
basically=3DA0 the thicker the plaster is applied the hotter it will get. T=
ha=3D
t's why it should be applied in thin layers. Or something to that effect.=
=3D
=3DA0 Here's the link to the story I read:
http://news.bbc.co.uk/2/hi/uk_news/education/6485481.stm
Logan Johnson=3D20
Yakima Valley Pottery & Supply=3D20
719 w. Nob Hill blvd.=3D20
Yakima Wa. 98902=3D20
(509) 469-6966=3D20
www.yakimavalleypottery.net
--- On Wed, 10/14/09, Vince Pitelka wrote:
From: Vince Pitelka
Subject: Re: plaster accident
The actual story is at
http://news.bbc.co.uk/2/hi/uk_news/england/lincolnshire/8303246.stm.=3DA0 I=
t'=3D
s a
pretty sad situation,
http://iweb.tntech.edu/wpitelka
=3D0A=3D0A=3D0A
john.eden@MAINE.EDU on wed 14 oct 09
Unfortunately Nils it is not an urban legend, it happened in January
2007 in Lincolnshire, UK.
It was an article on the BBC World News the day before yesterday
For those who would like a copy go to www,bbc.co.uk/
Then put "plaster accident" into the search box at the top of the page
Then go down to approximately the 7th article titled
News. Lincolnshire fine art student loses fingers.
Be warned it is graphic.
John
Vince Pitelka on wed 14 oct 09
The actual story is at
http://news.bbc.co.uk/2/hi/uk_news/england/lincolnshire/8303246.stm. It's =
a
pretty sad situation, but you really have to admire the girl's
determination. She has returned to art school after losing eight fingers.
I don't do much plaster casting but have been around it peripherally for th=
e
past 40 years, and I have never heard of something like this. I have heard
plenty of stories from people who have done casts of body parts and
experienced an uncomfortable amount of heat, but never any that produced
serious burns. The article said that plaster, while setting, can produce
temperatures of 60 degrees Centigrade, which is 140 degrees Fahrenheit.
Does anyone know what situations favor creation of more heat in the setting
of plaster?
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka
Marcia Selsor on wed 14 oct 09
Vince,
I have never heard of burns to that degree either. I have done face
masks many times.
Could the plaster rea;ly cause that type of burn?
Is it different from US plaster? Does Plaster of Paris really get that
hot?
Could it be faulty plaster?
I don't know. But I am really glad the pottery and/or casting plaster
I have used with students never got that hot.
Marcia
On Oct 14, 2009, at 7:17 PM, Vince Pitelka wrote:
> The actual story is at
> http://news.bbc.co.uk/2/hi/uk_news/england/lincolnshire/
> 8303246.stm. It's a
> pretty sad situation, but you really have to admire the girl's
> determination. She has returned to art school after losing eight
> fingers.
> I don't do much plaster casting but have been around it peripherally
> for the
> past 40 years, and I have never heard of something like this. I
> have heard
> plenty of stories from people who have done casts of body parts and
> experienced an uncomfortable amount of heat, but never any that
> produced
> serious burns. The article said that plaster, while setting, can
> produce
> temperatures of 60 degrees Centigrade, which is 140 degrees
> Fahrenheit.
> Does anyone know what situations favor creation of more heat in the
> setting
> of plaster?
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net; wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka
>
Marcia Selsor
http://marciaselsor.com
jonathan byler on wed 14 oct 09
high volume/low surface area; i.e. very thick sections of plaster that =3D2=
0=3D
completely surround something like your hand.. I wouldn't be =3D20
surprised if temperatures could get even hotter than 140=3DB0F if there =3D=
20=3D
was enough plaster around it to insulate itself. all that heat that =3D20
gets produced in the chemical reaction when it sets has a hard time =3D20
dissipating when there is high volume and low surface area. using hot =3D2=
0=3D
water to begin with as someone else mentioned will speed the reaction, =3D2=
0=3D
and I would guess would also make more heat. they warn you on the bag =3D2=
0=3D
here not to enclose body parts with it. I guess all those hot-coffee =3D20=
=3D
labels are not for naught, except very few people actually read them.
if you are curious just how hot you can get it, buy a digital meat =3D20
thermometer or thermocouple and stick it into the middle of a 5 gallon =3D2=
0=3D
bucket of plaster sometime as it cures.
it is the same with concrete, too. they had to develop special =3D20
concrete to pour the extra thick sections of the hoover dam. and even =3D2=
0=3D
on top of that they had to run pipes and cooling water through the =3D20
concrete as it cured. if you pour regular concrete thick enough it =3D20
will get so hot and stay so hot inside that it starts to break down =3D20
and loose strength.
On Oct 14, 2009, at 7:17 PM, Vince Pitelka wrote:
> The actual story is at
> http://news.bbc.co.uk/2/hi/uk_news/england/lincolnshire/=3D20
> 8303246.stm. It's a
> pretty sad situation, but you really have to admire the girl's
> determination. She has returned to art school after losing eight =3D20
> fingers.
> I don't do much plaster casting but have been around it peripherally =3D2=
0=3D
> for the
> past 40 years, and I have never heard of something like this. I =3D20
> have heard
> plenty of stories from people who have done casts of body parts and
> experienced an uncomfortable amount of heat, but never any that =3D20
> produced
> serious burns. The article said that plaster, while setting, can =3D20
> produce
> temperatures of 60 degrees Centigrade, which is 140 degrees =3D20
> Fahrenheit.
> Does anyone know what situations favor creation of more heat in the =3D20=
=3D
> setting
> of plaster?
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net; wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka
Randall Moody on wed 14 oct 09
On Wed, Oct 14, 2009 at 8:17 PM, Vince Pitelka wrote:
> The actual story is at
> http://news.bbc.co.uk/2/hi/uk_news/england/lincolnshire/8303246.stm. It'=
s
> a
> pretty sad situation, but you really have to admire the girl's
> determination. She has returned to art school after losing eight fingers=
.
> I don't do much plaster casting but have been around it peripherally for
> the
> past 40 years, and I have never heard of something like this. I have hea=
rd
> plenty of stories from people who have done casts of body parts and
> experienced an uncomfortable amount of heat, but never any that produced
> serious burns. The article said that plaster, while setting, can produce
> temperatures of 60 degrees Centigrade, which is 140 degrees Fahrenheit.
> Does anyone know what situations favor creation of more heat in the setti=
ng
> of plaster?
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net; wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka
>
From the article: "Jo Anderson, prosecuting for the HSE, said the girl had
been told by her teacher to put her hands into clay to make a mould.
She was then supposed to pour the liquid plaster into the clay mould.
Instead she put her hand up to the wrist into the bucket of plaster."
Not to diminish what the poor girl went through but why was the school fine=
d
for her not following directions?
Vince, everything that I could find said "up to 140 degrees". I took that a=
s
a top out but prolonged exposure could be more the issue.
--
Randall in Atlanta
Vince Pitelka on thu 15 oct 09
Randall in Atlanta wrote:
"Vince, everything that I could find said "up to 140 degrees". I took that
as
a top out but prolonged exposure could be more the issue."
Randall -
I guess I did not state my question very well. I was not implying that
temperatures greater than 140F would be created, although a post today says
that temperatures as high as 150F are possible. What I was inquiring about
was the conditions most favorable for producing this kind of temperature in
plaster. At this point it seems that the problems occur with the use of ho=
t
water to accelerate the process, and when casting larger masses where
greater heat develops near the core.
When a person is doing an "open-face' mold of a hand, arm, or face, with a
proper parting compound, I cannot see a safety issue, because if the plaste=
r
starts to get uncomfortably hot the person can simply pull away from the
plaster. This is how it has always been done in art schools all over the
country and the world, and I have never heard of any sort of injury.
In the British articles about this problem, they said that a previous
student had lost several fingers in an accident involving burns from
plaster, so I am curious as to why people were not being more vigilant.
Sure, this poor girl did something pretty foolish by immersing both of her
hands in a bucket of plaster and letting it set up, but someone should have
warned her that plaster is capable of producing temperatures that can cause
severe burns, and you would think that the word would have been spread far
and wide after another student suffered the loss of several fingers.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka
John Rodgers on thu 15 oct 09
Vince,
Assuming the plaster is the same as USG plaster - and depending on what
type of plaster - I think it possible to sustain burns if the mass of
the plaster is sufficient to impede the dissipation of the heat of
hydration. Given that fish can be cooked at 140-150 degrees F, and if as
with an electric kiln - the rate of heat development in the core (of the
plaster mass, in this case) exceeds the rate of heat dissipation, burns
most likely will occur. Given that these seemingly low temperatures are
accompanied by moisture, burn damage is much more likely to occur. This
is of course - conjecture on my part - but it is based on long
experience working with plasters of various types. I have seen mass
pours for large projects get quite hot, and I definitely would not want
my hand immersed in it when it is that hot.
My $0.02.
Regards,
John Rodgers
Chelsea, AL
Vince Pitelka wrote:
> The actual story is at
> http://news.bbc.co.uk/2/hi/uk_news/england/lincolnshire/8303246.stm. It'=
s a
> pretty sad situation, but you really have to admire the girl's
> determination. She has returned to art school after losing eight fingers=
.
> I don't do much plaster casting but have been around it peripherally for =
the
> past 40 years, and I have never heard of something like this. I have hea=
rd
> plenty of stories from people who have done casts of body parts and
> experienced an uncomfortable amount of heat, but never any that produced
> serious burns. The article said that plaster, while setting, can produce
> temperatures of 60 degrees Centigrade, which is 140 degrees Fahrenheit.
> Does anyone know what situations favor creation of more heat in the setti=
ng
> of plaster?
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft
> Tennessee Tech University
> vpitelka@dtccom.net; wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka
>
>
>
Bruce Girrell on thu 15 oct 09
Didn't anyone in that whole school have a hammer or other object heavy enou=
=3D
gh to smash the plaster?
Were they worried that they would ruin the mold?
There's more to this story than we're hearing.
Bruce Girrell=3D
Lis Allison on thu 15 oct 09
On Wednesday 14 October 2009, Vince Pitelka wrote:
> Centigrade, which is 140 degrees Fahrenheit. Does anyone know what
> situations favor creation of more heat in the setting of plaster?
I am sure using hot water to mix plaster makes it get hotter as it sets,
but I don't know how much hotter. And of course the larger the volume of
plaster the hotter it gets inside it.
I had another thought about that poor girl: probably they couldn't get the
pail off (maybe a metal pail) and so couldn't smash the plaster. Also
plaster doesn't get hot until after it is quite stiff, so she couldn't
have pulled her hands out once it got uncomfortable as someone on the list
suggested.
Lis
--
Elisabeth Allison
Pine Ridge Studio
www.Pine-Ridge-Studio.blogspot.com
Lis Allison on thu 15 oct 09
On Wednesday 14 October 2009, Marcia Selsor wrote:
> Vince,
> I have never heard of burns to that degree either. I have done face
> masks many times.
> Could the plaster rea;ly cause that type of burn?
> Is it different from US plaster? Does Plaster of Paris really get that
> hot?
I think it's that plaster is itself a very poor conducter of heat, in
other words, heat generated inside a large block will not be dispersed
very quickly. That is likely what did it. The outside of a setting block
will always feel much cooler than the inside is. Thin layer, no probbies,
thick layer, could be ouch.
And there are many grades of plaster, perhaps the denser ones do get
hotter.
Lis
--
Elisabeth Allison
Pine Ridge Studio
www.Pine-Ridge-Studio.blogspot.com
Fisher Cheryl on thu 15 oct 09
Originally I wasn't reading this thread. Made the assumption that it
was something about mixing it wrong. After perusing the e-mails, it
brought back a reminder of doing a hand casting in plaster in high
school (back before water was invented and dirt was new and dinosaurs
roamed the earth). The only thing I remember at the time was making
sure fingers were not in an odd position so you could pull your hand
out easily. Don't remember mishaps with anyone else and I only did one
hand.
Cheryl Fisher
potterytalk@verizon.net
Sarasota, FL
ivor & olive lewis on fri 16 oct 09
I seem to recall that Proteins become "De-Natured" when they are subject to
a temperature greater than 54 deg Celsius, say 129 deg F. That's halfway to
the boiling point of water.
Our thermostat is set to 50 deg C. IN some situations where there are
showers the temperature is controlled to about 42 deg C as a safety
precaution.
Check it out.
Best regards,
Ivor Lewis,
Redhill,
South Australia
Bonnie Staffel on fri 16 oct 09
Hi Clayarters,
I used to make face masks from the wet plaster. A friend of mine had a =3D
very
interesting face structure and he wanted me to make a mask of him. I
proceeded to do it, making sure to leave the nostrils open, and greased =3D
up
his face very well.
When it came time to take it off, we had a big problem. He had a large
undercut under his chin and when we tried to pull is off, it just =3D
wouldn't
come as the plaster was being held by the hollow part. Finally through a =
=3D
lot
of struggling, it finally came off. That was a really scary situation.=3D20
After that I found the plaster gauze material and used that with a lot =3D
of
success. I reinforced it after taking the mask off the face and then =3D
used
them to make clay mask reproductions for the subject.=3D20
Bonnie
http://webpages.charter.net/bstaffel/
http://vasefinder.com/bstaffelgallery1.html
DVD=3DA0 Throwing with Coils and Slabs
DVD=3DA0 Introduction to Wheel Work
Charter Member Potters Council
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