Ababi on wed 5 dec 01
In my last letter I sent a recipe of a test I made
Ababi's ^6 Porcelain
====================
NEPHELINE SYENITE... 200.00 19.61%
EPK KAOLIN...... 700.00 68.63%
Molochite........... 100.00 9.80%
BENTONITE........... 20.00 1.96%
========
1020.00
CaO 0.07* 0.24%
MgO 0.06* 0.15%
K2O 0.26* 1.56%
Na2O 0.61* 2.37%
TiO2 0.06 0.30%
Al2O3 6.09 38.99%
P2O5 0.02 0.20%
SiO2 14.69 55.40%
Fe2O3 0.08 0.79%
Text1 5.83
Si:Al 2.41
SiB:Al 2.41
Expan 6.01
I tried to imitate the Limoges by making ^6 claybody without ball clay.
It felt like Limoges but if you will look carefully at the test tiles
you will see that they are cracked in the ends. The broken one, started
to break before the bisque.
The missing one fall to the floor.
It received properly most of the glazes
I would like to know what you think about it I
made also measurements
cut to 10 tiles 10X 5 +? C'm
Bone dry average weight:50.09grams length:9.62
Bisque was to 1000C Weight: 42.11 length: 9.422 I did not check
absorption
Than I applied different glazes you can see , ignored the fact that
one tile was broken.
Now After 1220C. Average wight:43.944 (there is the weight of the glaze
too)
After boiling 3 hours and drying with a towel:45.11 for a tile
Length:8.6 C'm.
But, I do not know how to calculate the absorption!
Thank you for any help
Ababi Sharon
Kibbutz Shoval- Israel
Glaze addict But claybodies? Maybe!
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
http://www.israelceramics.org/
Snail Scott on wed 5 dec 01
At 07:32 AM 12/5/01 +0200, Ababi wrote:
>Bone dry average weight:50.09grams...
>Bisque was to 1000C Weight: 42.11...
> Than I applied different glazes...
>Now After 1220C. Average wight:43.944...
>After boiling 3 hours and drying with a towel:45.11...
>
>But, I do not know how to calculate the absorption!
I would assume that the bisque took care of most of the
LOI, so the weight of just the clay is probably about
the same even after the glaze fire. So, I'd go through
the normal calculation process for finding absorption,
but use the bisque weight as the 'dry weight' number,
and subtract the weight of the glaze from your 'wet
weight' number before calculating your absorption.
(Someone tell me if I'm wrong about the LOI, OK?)
So:
Glazed test weight (43.944) minus bisque test weight
(42.11) equals weight of glaze (1.834).
'Wet' weight as measured (45.11) minus weight of glaze
(1.834) equals 'wet weight' of clay alone (43.276).
45.11 minus 42.11 equals 3.0
3.0 divided by 42.11 equals .007...
.007 times 100 equals .7% absorption.
There's probably some degree of error introduced by
my previous assumptions, but this might be in the
ballpark, anyway...
-Snail
Ron Roy on mon 10 dec 01
Hi Snail,
I don't know for sure what the difference might be - easy to do the
experiment and find out for sure.
I would say most of the LOI is water and that is gone for sure - and so is
the carbon and sulphur etc. Yes I would say so but if you do the experiment
- best to do it on a "heavy" piece of clay cause I think any diff will be
small.
Made me think! and that is what keeps me going.
RR
>I would assume that the bisque took care of most of the
>LOI, so the weight of just the clay is probably about
>the same even after the glaze fire. So, I'd go through
>the normal calculation process for finding absorption,
>but use the bisque weight as the 'dry weight' number,
>and subtract the weight of the glaze from your 'wet
>weight' number before calculating your absorption.
>
>(Someone tell me if I'm wrong about the LOI, OK?)
Ron Roy
RR# 4
15084 Little Lake Rd..
Brighton,
Ontario, Canada
KOK 1H0
Residence 613-475-9544
Studio 613-475-3715
Fax 613-475-3513
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