Ron Collins on sat 9 jun 01
I hope that someone can offer advice:
I tried a recipe published in CM some years back--it said it was for 06, =
and I thought I'd try it since it only had 15% frit/imported product, =
even though it didn't sound like it would melt ... It does not melt, =
even at cone 6. But it has a similar texture to Velvets--I thought I'd =
use it like an engobe, with Mason stains looking good: it is:
soda ash 6
frit 3110 15
bentonite 4
ball clay 30
flint 45
I usually add 10% Black 6600 stain
The problem: when put on greenware, and bisque fired, on my =
earthenware, which is a good body and gives me no trouble ever with =
anything else-when clear glazed , or ANY glaze the glaze crawls badly. =
This is a good clear and has been the basis of many of my glaze =
experimentation--I got it off of clayart. It is:
60% Frit 3134
40% Ball Clay
I know this is a very simple glaze but it fits my earthenware and works =
well. What is the problem with my "velvet" glaze that it doesn't like =
to be clear glazed? I fire both bisque and glazes to 04, and have =
adjusted everything accordingly, because my kiln is so small and I fire =
a lot of student work and need to fill it as full as possible, with =
whatever will fit. ANYWAY....
I have a bucketful made up-dry-with no stains added, so it would be =
a simple matter to adjust the glaze, but I can't remake it because I'm =
about out of 3110 and have to wait until I go back to US or someone =
comes here to get more, and this is the only thing that I use 3110 for. =
Sorry that this is lengthy, but could use some advice on WHY it is =
happening, and WHAT to do about it....many thanks....Melinda=20
Ababi on sun 10 jun 01
Hello Melinda
Look at your recipe
soda ash............ 6.00 6.00%
frit 3110........... 15.00 15.00%
bentonite........... 4.00 4.00%
ball clay........... 30.00 30.00%
flint............... 45.00 45.00%
========
100.00
CaO 0.36* 2.89%
MgO 0.15* 0.84%
K2O 0.05* 0.62%
Na2O 0.45* 3.99%
TiO2 0.00 0.04%
Al2O3 0.86 12.63%
B2O3 0.04 0.43%
SiO2 9.06 78.07%
Fe2O3 0.02 0.49%
Si:Al 10.49
SiB:Al 10.54
Expan 5.81
When you decrease the frit, you increase alumina and silica 0.86 mol of
alumina, does not melt for sure in ^6 I don't think it will melt in cone
10. I never fired that high.
The expansion is too low too , means it must be too much crawling.
How to adjust what you have in the bucket?
try to add more soda ash or soda bicarbonate.up to 20or 30% but mix with
water only the amount you need because it is a soluble glaze You can use
wood ash and lithium as well as Pearle ash (K2O) also Borax, these materials
are used also out of the ceramic world, the borax and K2O are used as far as
I know in the laundry world. You can send me off list your available
materials and I, instead of listen to the news, will formulate you a velvet
glaze!
Ababi Sharon
ababisharon@hotmail.com
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
----- Original Message -----
From: "Ron Collins"
To:
Sent: Saturday, June 09, 2001 7:56 PM
Subject: need glaze help
I hope that someone can offer advice:
I tried a recipe published in CM some years back--it said it was for 06, and
I thought I'd try it since it only had 15% frit/imported product, even
though it didn't sound like it would melt ... It does not melt, even at
cone 6. But it has a similar texture to Velvets--I thought I'd use it like
an engobe, with Mason stains looking good: it is:
soda ash 6
frit 3110 15
bentonite 4
ball clay 30
flint 45
I usually add 10% Black 6600 stain
The problem: when put on greenware, and bisque fired, on my earthenware,
which is a good body and gives me no trouble ever with anything else-when
clear glazed , or ANY glaze the glaze crawls badly. This is a good clear
and has been the basis of many of my glaze experimentation--I got it off of
clayart. It is:
60% Frit 3134
40% Ball Clay
I know this is a very simple glaze but it fits my earthenware and works
well. What is the problem with my "velvet" glaze that it doesn't like to be
clear glazed? I fire both bisque and glazes to 04, and have adjusted
everything accordingly, because my kiln is so small and I fire a lot of
student work and need to fill it as full as possible, with whatever will
fit. ANYWAY....
I have a bucketful made up-dry-with no stains added, so it would be a
simple matter to adjust the glaze, but I can't remake it because I'm about
out of 3110 and have to wait until I go back to US or someone comes here to
get more, and this is the only thing that I use 3110 for. Sorry that this
is lengthy, but could use some advice on WHY it is happening, and WHAT to do
about it....many thanks....Melinda
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