Steve Slatin on sun 17 oct 10
Ann -- Concrete is cement mixed with water, sand,
and gravel. In its dry form, it's silica, calcium,
alumina, and generally some iron. IIRC, the percentages
can vary rather substantially from different=3D20
manufacturers. It is usually sourced from=3D20
limestone, sand, and clay.
Naturally, given the materials therein, it can
be a part of a glaze -- though depending on the
proportions in the material, the nature of the
gravel included (if concrete) and firing temp,
it may or may not make a useful glaze.
=3D20
Steve Slatin --=3D20
N48.0886450
W123.1420482
--- On Sun, 10/17/10, Ann Brink wrote:
I just
> did a ^7 firing,
> repeated the test, and the powder melted into a round ball
> shape,
> semi-glossy, with specks, kind of taffy colored.=3DA0
> Interesting enough for me
> to make several small test batches of glaze.
>=3D20
> Have any of you used something similiar?=3DA0 I should
> google cement/concrete
> and see what it's made of.
>=3D20
> Ann Brink in Lompoc CA
> (mostly about
> pottery)
> =3D0A=3D0A=3D0A
David Hendley on sun 17 oct 10
Yes, cement can be useful ingredient in stoneware glazes.
My professor in college, back in the old days, liked
to make up batches of cement glaze. I never saw the
point, as the cement would set and the glaze would
be useless in half an hour. I think it was just showmanship.
Concrete dust is another matter, as it will also have
pieces of rock and sand in it. Sounds to me like that
would make it more refractory, but who knows. That
seems to be consistent with your result. Every batch
of concrete will be different, depending on the aggregate
used in the original concrete mix.
David Hendley
david@farmpots.com
http://www.farmpots.com
http://www.thewahooligans.com
----- Original Message -----
> I was given about a gallon sized baggie filled with fine powder- the
> residue
> of the sawing of bricks being used to lay a patio floor.
> I put a little pile of the powder in my next bisque firing, (on a shard
> with
> alumina hydrate on it) and nothing happened. I just did a ^7 firing,
> repeated the test, and the powder melted into a round ball shape,
> semi-glossy, with specks, kind of taffy colored. Interesting enough for
> me
> to make several small test batches of glaze.
Ann Brink on sun 17 oct 10
Hello All:
I was given about a gallon sized baggie filled with fine powder- the residu=
e
of the sawing of bricks being used to lay a patio floor. My grandson,
knowing my habit of melting things, thought I would like to experiment with
it. At first I thought he was using clay bricks and told him "Oh, you've
made grog"., but it turned out these bricks were concrete.
I put a little pile of the powder in my next bisque firing, (on a shard wit=
h
alumina hydrate on it) and nothing happened. I just did a ^7 firing,
repeated the test, and the powder melted into a round ball shape,
semi-glossy, with specks, kind of taffy colored. Interesting enough for me
to make several small test batches of glaze.
Have any of you used something similiar? I should google cement/concrete
and see what it's made of.
Ann Brink in Lompoc CA
(mostly about pottery)
William & Susan Schran User on sun 17 oct 10
On 10/17/10 3:39 PM, "Ann Brink" wrote:
> Have any of you used something similiar? I should google cement/concrete
> and see what it's made of.
There was an article many, many years ago in Ceramics Monthly about using
Portland cement as a glaze ingredient.
I think the article was by Behrens.
I then did a search and discovered this in the archives:
http://www.potters.org/subject39808.htm/
This posting lists, low and high fire glazes using the cement that you can
probably use your cement dust as a sub.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
| |
|
