Marni Turkel on fri 14 sep 07
You didn't say what plaster you were using, but I calculate 2178
cubic inches = 1.2604 cubic feet which would be 78.15 lbs of plaster
pottery #1. with 54.70 lbs of water. You're going to need a big
bucket, I'd try a 10 gallon.
There is a great slide rule type plaster calculator that I got years
ago from US Gypsum. It also came with one of the mold making books.
--
Marni Turkel
2080 Llano Rd 1B
Santa Rosa, CA 95407
Phone 707-579-5567
Fax 707-579-1116
Stony Point Ceramic Design
http://www.marniturkel.com
http://www.BarrelRims.com
Sonoma Urn Company
http://www.sonomaurn.com
Ingeborg Foco on fri 14 sep 07
Hi Clay People,
Can someone please tell me how to calculate the quantity of plaster needed
to fill a 33" x33" x2"
space i.e. how many pounds of plaster do I need to fill this space? I know
how to weigh and measure the proportions of water
to plaster but no where can I find the way to calculate the quantity of
plaster required. It's not a catastrophe if I end up with
too much but to be short would not be desirable.
Thanks in advance for any information.
Sincerely,
Ingeborg
www.thepottersworkshop.com
Randall Moody on fri 14 sep 07
I can't remember the formula but you can use a USG Plaster/Volume and Mix
Calculator available form US Gypsum in Chicago. I got mine for free but it
is in the black hole of my bookcase at the moment. I will see if I can find
it tonight. You will also need to know the type of plaster you are using for
the correct plaster to water ratio.
Randall.
On 9/14/07, Ingeborg Foco wrote:
>
> Hi Clay People,
>
> Can someone please tell me how to calculate the quantity of
> plaster needed
> to fill a 33" x33" x2"
> space i.e. how many pounds of plaster do I need to fill this space? I
> know
> how to weigh and measure the proportions of water
> to plaster but no where can I find the way to calculate the quantity of
> plaster required. It's not a catastrophe if I end up with
> too much but to be short would not be desirable.
>
> Thanks in advance for any information.
>
>
> Sincerely,
>
> Ingeborg
>
> www.thepottersworkshop.com
>
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
>
Charlie Cummings on fri 14 sep 07
Ingeborg,
I'm assuming you want an absorbent slab and that you are using
pottery plaster #1 at a consistency of 70.
Multiply the dimensions and divide the total by 80. This will tell
you how many quarts of water you need.
33 x 33 x 2 = 2178 cubic inches
2178 cubic inches / 80 cubic inches per quart water = 27.2 quarts.
The proportion of plaster to water is- 1248g/quart
You'll need 33945grams or 33.7 kilos ( x 2.2lb/kilo = 74.13 pounds)
I would probably round up to 30 quarts to be sure there was
extra. That means you need 82 pounds of plaster.
USG pottery plaster #1 information
http://www.gypsumsolutions.com/application.asp?prod=49&app=Ceramics
Click on the "Gypsum Products Consistency Calculator "
Charlie Cummings
At 08:33 AM 9/14/2007, you wrote:
>Hi Clay People,
>
>Can someone please tell me how to calculate the quantity of plaster
Charlie Cummings Clay Studio & Gallery
4130 South Clinton Street
Fort Wayne, IN 46806
Charlie@claylink.com
260-458-9160
www.claylink.com
Ingeborg Foco on fri 14 sep 07
Dear Charlie,
Yes, I am using Pottery Plaster #1 and I need to pour my wedging table. I
have been to the USG site several times and have emailed/spoken to their
customer service rep. They are quite helpful and so is their web site but
no where did I find a chart on how to figure the volume of poured plaster.
I've been cautioned to be sure to weigh the water rather than measure, weigh
the plaster, mix it with a certain type of paddle (which I purchased) not to
over fill the container,hold
the paddle at a certain angle and have both the water and the plaster at a
certain temperature etc etc. It all sounds rather technical compared to the
way I usually mix small batches. I forget now how cool it was supposed to
be but living in SW Florida makes it pretty hard to have everything
chilled. (my studio does not have AC and the water is like bath water. I
hope to make this a monolithic pour and unless I can figure out how to time
things I will most likely have to enlist help to get that kind of quantity
poured all at once.
I thank you for your help and calculations...maybe you would like to come
and help me pour the slab? :) I suppose I could find volunteers from the
North about January. Unfortunately, I need to pour my table within the next
couple of weeks.
Again thanks
Sincerely,
Ingeborg
thepottersworkshop.com
On 9/14/07, Charlie Cummings wrote:
>
> Ingeborg,
>
> I'm assuming you want an absorbent slab and that you are using
> pottery plaster #1 at a consistency of 70.
>
> Multiply the dimensions and divide the total by 80. This will tell
> you how many quarts of water you need.
>
> 33 x 33 x 2 = 2178 cubic inches
>
> 2178 cubic inches / 80 cubic inches per quart water = 27.2 quarts.
>
> The proportion of plaster to water is- 1248g/quart
>
> You'll need 33945grams or 33.7 kilos ( x 2.2lb/kilo = 74.13 pounds)
>
> I would probably round up to 30 quarts to be sure there was
> extra. That means you need 82 pounds of plaster.
>
>
> USG pottery plaster #1 information
> http://www.gypsumsolutions.com/application.asp?prod=49&app=Ceramics
> Click on the "Gypsum Products Consistency Calculator "
>
> Charlie Cummings
>
>
> At 08:33 AM 9/14/2007, you wrote:
> >Hi Clay People,
> >
> >Can someone please tell me how to calculate the quantity of plaster
>
>
> Charlie Cummings Clay Studio & Gallery
> 4130 South Clinton Street
> Fort Wayne, IN 46806
> Charlie@claylink.com
> 260-458-9160
> www.claylink.com
>
>
> ______________________________________________________________________________
>
Bill Merrill on fri 14 sep 07
For every 80 cubic inches of plaster you need....1 quart of water plus 2
3/4 pounds of plaster.
Bill
billm@pcadmin.ctc.edu
pounds of plaster 3/4=20
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Randall
Moody
Sent: Friday, September 14, 2007 10:47 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Calculating Plaster volume
I can't remember the formula but you can use a USG Plaster/Volume and
Mix
Calculator available form US Gypsum in Chicago. I got mine for free but
it
is in the black hole of my bookcase at the moment. I will see if I can
find
it tonight. You will also need to know the type of plaster you are using
for
the correct plaster to water ratio.
Randall.
On 9/14/07, Ingeborg Foco wrote:
>
> Hi Clay People,
>
> Can someone please tell me how to calculate the quantity of
> plaster needed
> to fill a 33" x33" x2"
> space i.e. how many pounds of plaster do I need to fill this space? I
> know
> how to weigh and measure the proportions of water
> to plaster but no where can I find the way to calculate the quantity
of
> plaster required. It's not a catastrophe if I end up with
> too much but to be short would not be desirable.
>
> Thanks in advance for any information.
>
>
> Sincerely,
>
> Ingeborg
>
> www.thepottersworkshop.com
>
>
>
________________________________________________________________________
______
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
>
________________________________________________________________________
______
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots2@visi.com
Michael Wendt on fri 14 sep 07
Ingeborg,
I just measured a slump mold made to 67 density and
it works out to 44 LBS/cubic foot so figure the
Length X Width X Thickness in inches and divide that
number by 1728 (the number of cubic inches in a cu ft.)
Multiply the volume by 44 and you should be close.
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave.
Lewiston, Id 83501
U.S.A.
208-746-3724
wendtpot@lewiston.com
http://www.wendtpottery.com
http://UniquePorcelainDesigns.com
Cindy reed on fri 14 sep 07
I took a mold making class last spring and this is a water to plaster table
we used at school:
Water @ 72=B0F/22=B0C Plaster
A. 236 ml (cc) 11 oz. 312 grams
B. 473 ml (cc) 1 lb. 6 oz. 642 grams
C. 946 ml (cc) 2 lb. 12 oz. 1.248 grams
D. 1,419 ml (cc) 4 lb. 2 oz. 1,872 grams
E. 1,892 ml (cc) 5 lb. 8 oz. 2,497 grams
F. 2,365 ml (cc) 6 lb. 14 oz. 3,021 grams
G. 2,839 ml (cc) 8 lb. 4 oz. 3,744 grams
H. 3,312 ml (cc) 9 lb. 10 oz. 4,388 grams
I. 3,785 ml (cc) 11 lb. 4,992 grams
J. 5,678 ml (cc) 16 lb. 8 oz. 7,488 grams
K. 7,570 ml (cc) 22 lb. 9,984 grams
L. 9,463 ml (cc) 27 lb. 8 oz. 12,480 grams
M. 11,356 ml (cc) 33 lb. 14,976 grams
Example: 946 ml water + 1,248 grams dry plaster =3D 1,330 cc mixed plaster.
Final mix will yield approximately 1.4 times the volume of water.
Use centimeters to measure your container, Length * Width * Height
So if your area is 22.5 * 11.3 * 6.4 =3D 1627.2
You could mix up quantities in in line "D" (you will have plenty of extra)
or you could divide 1627.2 by 1.4 which will yield 1,162 and use quantities
in line "C" which will give you extra but not way to much extra. Have a
container ready to pour any extra plaster mixture into to create hump molds=
.
We measured out both water and plaster then poured plaster into our water
and let soak for 2 minutes, then mixed gently for 2-3 minutes then poured.
Hope this helps you,
Cindy Reed
Greenville, NC=20
On 9/14/07 4:15 PM, "Ingeborg Foco" wrote:
> Dear Charlie,
>=20
> Yes, I am using Pottery Plaster #1 and I need to pour my wedging table. =
I
> have been to the USG site several times and have emailed/spoken to their
> customer service rep. They are quite helpful and so is their web site bu=
t
> no where did I find a chart on how to figure the volume of poured plaster=
.
>=20
> I've been cautioned to be sure to weigh the water rather than measure, we=
igh
> the plaster, mix it with a certain type of paddle (which I purchased) not=
to
> over fill the container,hold
> the paddle at a certain angle and have both the water and the plaster at =
a
> certain temperature etc etc. It all sounds rather technical compared to =
the
> way I usually mix small batches. I forget now how cool it was supposed t=
o
> be but living in SW Florida makes it pretty hard to have everything
> chilled. (my studio does not have AC and the water is like bath water. =
I
> hope to make this a monolithic pour and unless I can figure out how to ti=
me
> things I will most likely have to enlist help to get that kind of quantit=
y
> poured all at once.
>=20
> I thank you for your help and calculations...maybe you would like to com=
e
> and help me pour the slab? :) I suppose I could find volunteers from th=
e
> North about January. Unfortunately, I need to pour my table within the n=
ext
> couple of weeks.
>=20
> Again thanks
>=20
> Sincerely,
>=20
> Ingeborg
>=20
> thepottersworkshop.com
>=20
>=20
>=20
> On 9/14/07, Charlie Cummings wrote:
>>=20
>> Ingeborg,
>>=20
>> I'm assuming you want an absorbent slab and that you are using
>> pottery plaster #1 at a consistency of 70.
>>=20
>> Multiply the dimensions and divide the total by 80. This will tell
>> you how many quarts of water you need.
>>=20
>> 33 x 33 x 2 =3D 2178 cubic inches
>>=20
>> 2178 cubic inches / 80 cubic inches per quart water =3D 27.2 quarts.
>>=20
>> The proportion of plaster to water is- 1248g/quart
>>=20
>> You'll need 33945grams or 33.7 kilos ( x 2.2lb/kilo =3D 74.13 pounds)
>>=20
>> I would probably round up to 30 quarts to be sure there was
>> extra. That means you need 82 pounds of plaster.
>>=20
>>=20
>> USG pottery plaster #1 information
>> http://www.gypsumsolutions.com/application.asp?prod=3D49&app=3DCeramics
>> Click on the "Gypsum Products Consistency Calculator "
>>=20
>> Charlie Cummings
>>=20
>>=20
>> At 08:33 AM 9/14/2007, you wrote:
>>> Hi Clay People,
>>>=20
>>> Can someone please tell me how to calculate the quantity of plaster
>>=20
>>=20
>> Charlie Cummings Clay Studio & Gallery
>> 4130 South Clinton Street
>> Fort Wayne, IN 46806
>> Charlie@claylink.com
>> 260-458-9160
>> www.claylink.com
>>=20
>>=20
>>=20
___________________________________________________________________________=
__>>
_
>>=20
>=20
> _________________________________________________________________________=
_____
> Send postings to clayart@lsv.ceramics.org
>=20
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>=20
> Moderator of the list is Mel Jacobson who may be reached at melpots2@visi=
.com
Kathy Forer on sat 15 sep 07
On Sep 14, 2007, at 4:15 PM, Ingeborg Foco wrote:
> It all sounds rather technical compared to the
> way I usually mix small batches. I forget now how cool it was
> supposed to
> be but living in SW Florida makes it pretty hard to have everything
> chilled. (my studio does not have AC and the water is like bath
> water. I
> hope to make this a monolithic pour
Just to be sure of your plaster and timing, mix a small batch using
the same schedule and process you will use for your large batch.
It might be worth it to get a bag of ice from the store to help
retard setting. That's a lot of plaster to pour when warm. In lieu of
cold water, some glue, citric acid or boric acid will lightly slow
setting.
Kathy Forer
www.foreverink.com
May Luk on sat 15 sep 07
Hiya Plaster Mixer!
I use 100 ml water to 130 gm of plaster for press mould. I got the formula from Hamer Potters Dictionary and it's been great. {I used to eyeball and the result was mixed} If you want a denser mix, how about 140 gm to 100 ml water?
Be careful with your back when you pour a lot of plaster. I always get sore muscles after plaster mixing. I have to worry about leaks, shaking the bubbles and spillage on the floor. It can be quite tense. The bucket is heavy with so much liquid. So please take care with the body. Break into a few 'mix and pours' if necessary. I am sure you know about that already!
Regards
May
Maurice Weitman on sat 15 sep 07
There seems to be at least one typo in your=20
table... the second line I believe should be 624=20
grams, not 642. I haven't checked any others.
This leads me to suggest that one should=20
calculate amounts using a formula, forget tables.=20
Many formulae have been posted here, and there=20
are many available online. USG is a great, free=20
resource... one might say they're the source.
As Charlie Cummings already posted:
> >> USG pottery plaster #1 information
> >> http://www.gypsumsolutions.com/application.asp?prod=3D49&app=3DCeramic=
s
> >> Click on the "Gypsum Products Consistency Calculator "
Regards,
Maurice, in sunny Fairfax, California, where=20
between reflashing skylights, watching Leonard=20
Cohen videos, eating breakfast, I'm working up=20
the mother of all clayart rants. I might even=20
post it. Be afraid... very afraid!
At 22:59 -0400 on 9/14/07, Cindy reed wrote:
>I took a mold making class last spring and this is a water to plaster table
>we used at school:
>
>Water @ 72=B0F/22=B0C Plaster
>
>A. 236 ml (cc) 11 oz. 312 grams
>B. 473 ml (cc) 1 lb. 6 oz. 642 grams
Cindy reed on sat 15 sep 07
You are correct, I should have triple checked my qty's.
Thanks,
Cindy Reed
On 9/15/07 1:19 PM, "Maurice Weitman" wrote:
> There seems to be at least one typo in your
> table... the second line I believe should be 624
> grams, not 642. I haven't checked any others.
>=20
> This leads me to suggest that one should
> calculate amounts using a formula, forget tables.
> Many formulae have been posted here, and there
> are many available online. USG is a great, free
> resource... one might say they're the source.
>=20
> As Charlie Cummings already posted:
>=20
>>>> USG pottery plaster #1 information
>>>> http://www.gypsumsolutions.com/application.asp?prod=3D49&app=3DCeramics
>>>> Click on the "Gypsum Products Consistency Calculator "
>=20
> Regards,
> Maurice, in sunny Fairfax, California, where
> between reflashing skylights, watching Leonard
> Cohen videos, eating breakfast, I'm working up
> the mother of all clayart rants. I might even
> post it. Be afraid... very afraid!
>=20
>=20
> At 22:59 -0400 on 9/14/07, Cindy reed wrote:
>> I took a mold making class last spring and this is a water to plaster ta=
ble
>> we used at school:
>>=20
>> Water @ 72=B0F/22=B0C Plaster
>>=20
>> A. 236 ml (cc) 11 oz. 312 grams
>> B. 473 ml (cc) 1 lb. 6 oz. 642 grams
>=20
> _________________________________________________________________________=
_____
> Send postings to clayart@lsv.ceramics.org
>=20
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>=20
> Moderator of the list is Mel Jacobson who may be reached at melpots2@visi=
.com
| |
|
