Lili Krakowski on wed 23 nov 11
I measure most glazes and slips by volume, and wrote about it in =3D
PMI-Vol 2, Number 3 (Summer 1999). As I was preparing the article I =3D
also made a list of materials and their measure by weight, but that =3D
never saw print...However. Maybe I can find it, if so, I hope Mel will =3D
allow it on ClayArt.
The method works perfectly well for normal, common, glazes. I have NO =3D
idea how, if, it would do for finicky, tricky, special effects ones. =3D
Because I never use those.
I do not, by the way, think people "always" have weighed out glazes. =3D
And if they did , it likely was with plain balance scales--not the =3D
sophisticated, hi-tech ones now used. I think pail and bucket measuring =
=3D
to be much likelier in the old potteries.
There are two things to consider, nay, three.=3D20
Some materials are hygroscopic-- they can gain weight in humid =3D
atmospheres. This should not be a problem if you remain in same =3D
studio, and use relative new supplies of material. It might be if you =3D
moved from a dry to a wet climate, or measured out one batch of glaze =3D
during Monsoon season, and the next after six months of drought. A =3D
reminder that every new batch of glaze needs to be tested before use on =
=3D
actual pots.
Then: there may be a difference in volume of material if you dig the =3D
material out of the container with your measuring cup, or fill your =3D
measuring cup with a spoon. The former will compress the material, the =3D
latter will not. And, yes, drat, some materials compact and others =3D
don't. Which is why (oh, dear, not again) a new 10 lb packet of =3D
material may be more compressed than same material in the half-full 50 =3D
lbs that has been around "forever" . (See "test every batch above".)
|
Last. My white slip needs 13 cups of ball clay. After doing the =3D
standard US measuring cup bit a few times I made a measure just for =3D
the ball clay. I measured the 13 cups into a transparent plastic =3D
gallon jug, raised it to eye-level, made a mark. Repeated "test" =3D
several times. Finalized mark, wrote "13 c of ball clay " on container, =
=3D
et voila.
As I also have cottage cheese containers marked with volume of different =
=3D
materials I identify each clearly, and stash in a 5 gallon bucket. (Top =
=3D
of gallon containers can be cut off, down to an inch or so above the =3D
mark, to make stacking easier.
And: when I use a British cookbook I weigh things out--as they do. With =
=3D
US cookbooks I use their method--measuring cups and spoons.
And that's the scoop.
Lili Krakowski
Be of good courage
Lee on wed 23 nov 11
On Wed, Nov 23, 2011 at 7:24 AM, Lili Krakowski w=
=3D
rote:
> Some materials are hygroscopic-- they can gain weight in humid atmosphere=
=3D
s.
Traditionally in Japan, glazes are mixed by wet ladle measure. It is
a very damp climate. When you do wet measure, you don't have to worry
about hygroscopic differences.
I have woodash that is in water that I need to wash before everything
freezes up for the winter.
--
=3DA0Lee Love in Minneapolis
http://mingeisota.blogspot.com/
=3DA0"Ta tIr na n-=3DF3g ar chul an tI=3D97tIr dlainn trina ch=3DE9ile"=3D9=
7that is, =3D
"The
land of eternal youth is behind the house, a beautiful land fluent
within itself." -- John O'Donohue
John Rodgers on wed 23 nov 11
Can be done, often is. But - I personally prefer the precision of
weighing - across the board. And after a glaze is made up - I consider
weighing and establishing the density of the glaze to be crucial for the
best application.and to achieve the best success with the glaze when
firing. Just my nerdiness on the matter.
John
John Rodgers
Clayartist and Moldmaker
88'GL VW Bus Driver
Chelsea, AL
Http://www.moldhaus.com
On 11/23/2011 7:24 AM, Lili Krakowski wrote:
> I measure most glazes and slips by volume, and wrote about it in PMI-V=
ol 2, Number 3 (Summer 1999). As I was preparing the article I also made a=
list of materials and their measure by weight, but that never saw print..=
.However. Maybe I can find it, if so, I hope Mel will allow it on ClayArt.
>
> The method works perfectly well for normal, common, glazes. I have NO id=
ea how, if, it would do for finicky, tricky, special effects ones. Because =
I never use those.
>
> I do not, by the way, think people "always" have weighed out glazes. An=
d if they did , it likely was with plain balance scales--not the sophistica=
ted, hi-tech ones now used. I think pail and bucket measuring to be much l=
ikelier in the old potteries.
>
> There are two things to consider, nay, three.
>
> Some materials are hygroscopic-- they can gain weight in humid atmosphere=
s. This should not be a problem if you remain in same studio, and use rel=
ative new supplies of material. It might be if you moved from a dry to a w=
et climate, or measured out one batch of glaze during Monsoon season, and t=
he next after six months of drought. A reminder that every new batch of g=
laze needs to be tested before use on actual pots.
>
> Then: there may be a difference in volume of material if you dig the mate=
rial out of the container with your measuring cup, or fill your measuring c=
up with a spoon. The former will compress the material, the latter will no=
t. And, yes, drat, some materials compact and others don't. Which is why=
(oh, dear, not again) a new 10 lb packet of material may be more compresse=
d than same material in the half-full 50 lbs that has been around "forever"=
. (See "test every batch above".)
> |
> Last. My white slip needs 13 cups of ball clay. After doing the standa=
rd US measuring cup bit a few times I made a measure just for the ball cl=
ay. I measured the 13 cups into a transparent plastic gallon jug, raised=
it to eye-level, made a mark. Repeated "test" several times. Finalized m=
ark, wrote "13 c of ball clay " on container, et voila.
>
> As I also have cottage cheese containers marked with volume of different =
materials I identify each clearly, and stash in a 5 gallon bucket. (Top of=
gallon containers can be cut off, down to an inch or so above the mark, to=
make stacking easier.
>
> And: when I use a British cookbook I weigh things out--as they do. With =
US cookbooks I use their method--measuring cups and spoons.
>
> And that's the scoop.
>
>
>
>
>
>
>
>
>
> Lili Krakowski
> Be of good courage
>
>
| |
|
