Marcia Selsor on sun 16 aug 09
> From: Marcia Selsor
> Date: August 16, 2009 5:54:16 AM CDT
> To: alilly06@GMAIL.COM
> Subject: Re: Pounds of Plaster to Yield One Cu. Ft.??
>
> Don Frith's book on moldmaking has a chart/wheel in that back that
> calculates such things as needed by shapes including cylinders,
> spheres and squares.
> It also figures the consistency of the plaster and the amount of
> water needed.
> The chart is put out by US Gypsum.
> You should call them. The directions are rather complex so you
> should become familiar with it personally. You need to include what
> type of plaster you intend to use.
> Marcia Selsor
> On Aug 15, 2009, at 5:32 PM, Adron Lilly wrote:
>
>> On Fri, 14 Aug 2009 18:35:34 -0400, you wrote:
>>
>>> This should have been easier information to research. Google
>>> pretty much
>>> failed me. So did the folks at Home Despot.
>>>
>>> I simply want to estimate the amount of dry plaster I'll need to
>>> yield a
>>> cubic foot of finished casting. The goal? a wedging table of
>>> about 2'x4'
>>> working surface.
>>>
>>> Gurus? (or is that 'Guroi' ? ...) How many pounds of
>>> plaster will
>>> suffice to make this plaster table top?
>>>
>>> Thanks in advance for any info/urls/advice.
>>>
>>> Peace.
>>>
>>> Jeremy McLeod
>>
>>
>> I'm sure the following is from the clayart archives...
>>
>> Adron
>>
>>
>> DETERMINING AMOUNT OF PLASTER NEEDED FOR JOB
>>
>>
>> Determining the amount of plaster you will need: the mathematical
>> approach. This is really pretty simple and doesn't hurt at all. Once
>> you get the hang of it and reap the benefits of not having mountains
>> of excess plaster to dispose of you too will be a convert. Once your
>> mold boards are set up and clay is in place you will need to measure
>> the volume that is going to be filled in by the plaster during the
>> first pour. For our purposes we are going to be measuring cubic
>> inches. Say our mold boards form a rectangle that is 10" x 20" and
>> wants to be 2" thick: the calculations are 10 x 20=3D3D 200 x 2=3D3D 400
>> cubic inches.
>>
>> Okay, now that we know we are going to be mixing up enough plaster to
>> "occupy" 400 cubic inches we simply divide the number 400 by 80. That
>> just happens to work out to 5 in this case...5 what... you may be
>> wondering...well 5 in this example is how many QUARTS of water we
>> will
>> need for this specific pour. Each quart of water needs 2 pounds 14 =3D
>> ounces of plaster for a consistency of 70. Continuing the example =3D
>> above...we have determined we need 5 quarts of water for our pour.
>> When we multiply this 5 quarts by 2 pounds 14 ounces, we come up with
>> 14 pounds and 6 ounces. So in this example we would mix 5 quarts of
>> water with 14 pounds 6 ounces of plaster and this would be just
>> enough
>> plaster to fill the void..nothing more nothing less.
>>
>> Some smart person calculated that a quart of water and 2 pounds 14 =3D
>> ounces of plaster mixed will occupy 80 cubic inches...works every
>> time.
>>
>> As JB would say "hope this helps".
>>
>> Craig AZ
>>
>
> Marcia Selsor
> http://marciaselsor.com
>
>
>
>
Marcia Selsor
http://marciaselsor.com
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