May Luk on thu 2 jun 11
Hello all;
I have loads of B-mix clay scrap from my handbuilding. My original
workflow plan was to use the scrap clay for slipcasting and B-mix is
not made for that. Even though I use the scraps to make color slip for
painting. I still have lots of B-mix left. I want to make a glaze with
the B-mix to use it up. It does make a nice glaze slop without
bentonite or veegum because of its gel-like consistency.
This is my initial glaze recipe:
Custer Feldspar_______120 gm (1 part)
Frit 3195_____________240 gm (2 part)
B-mix _______________120 gm (1 part)
Silica________________120 gm (1 part)
It is cone 6 oxidation. The finish test is not mature and mildly
orange-peeled. It's cloudy and not transparent yet. It crazes where
thick.
The photo is here but there is not much to see for a transparent glaze test=
.
http://www.flickr.com/photos/yamerica/5792388852/in/photostream
What is the next step? I am guessing I need to add a secondary flux
(cheap one, not a frit) I'm thinking some calcium like Wollastonite
because I want to add more silica as well. (It's already cloudy,
whiting would be too gassy, I reckon) I don't know how much I need to
add as I don't have analysis for this. Should I start with 60 gm (half
part) and go from there?
Thanks in advance for your comments
May
--
http://twitter.com/MayLuk
http://www.ceramicsbrooklyn.com/
John Rodgers on fri 3 jun 11
May,
I use the B-mix throwing body AND the B-mix casting slip fairly
extensively. You are right - the B-mix throwing body does not make the
best slip. There is a fair difference in composition between the two,
and you can see it in the color when compared side by side. In small
quantities, however, the two can be mixed - ie, a little of one in a
whole lot of the other.
I got into using the C5 B-mix casting slip when I undertook a really big
project and there was no way to get the job done except through the
casting process. I didn't know at the time the B-mix slip mix was
available from Laguna until I called to see what they recommended.
Turned out they had already been down that road and had already
formulated the slip. So, I bought a ton or so for my project. It worked
very well. In fact, it worked better that the throwing body, because
when fired, it never cracked, never bloated, and glazes never pin holed.
An interesting contrast between the two after bisque firing was that the
slip would fire very white, and the throwing body had ever so slight a
yellow or off-white appearance - not that it made that much difference
when finished with a glaze.
Overall, I like both clays very much, and I specially like tha fact that
slip cast and thrown parts and pieces can be integrated together into
one piece of work without all kinds of troubles. They work very good
together.
Finally, I have found that when I have a bunch of scrap left over - slip
scrap goes back into the mixing vat, throwing clay goes onto a drying
table for slaking and reclaiming. In the past - for the latter, I would
dry it, crush it, slake it with enough water to make a very wet slurry,
then pour it out into a one inch thick slab on to my plaster table. The
plaster pulls the water and when sufficiently dried, I would turn the
slab to dry from the other side. When the clay was of the right
consistency, I rolled the clay into a roll, cut it into sections, then
slammrd it on the table to compress it, repeating this process numerous
times. Then I would wedge it. Finally, I would place it in plastic bags
for storage, ready for use. Nowadays, I run scrap through my old Walker
pug mill - which, I will say, I am thinking of selling, because I am
cutting back. These old bones don't work like they use'ta.
Good luck.
John
John Rodgers
Clayartist and Moldmaker
88'GL VW Bus Driver
Chelsea, AL
Http://www.moldhaus.com
On 6/2/2011 10:51 PM, May Luk wrote:
> Hello all;
>
> I have loads of B-mix clay scrap from my handbuilding. My original
> workflow plan was to use the scrap clay for slipcasting and B-mix is
> not made for that. Even though I use the scraps to make color slip for
> painting. I still have lots of B-mix left. I want to make a glaze with
> the B-mix to use it up. It does make a nice glaze slop without
> bentonite or veegum because of its gel-like consistency.
>
> This is my initial glaze recipe:
> Custer Feldspar_______120 gm (1 part)
> Frit 3195_____________240 gm (2 part)
> B-mix _______________120 gm (1 part)
> Silica________________120 gm (1 part)
>
> It is cone 6 oxidation. The finish test is not mature and mildly
> orange-peeled. It's cloudy and not transparent yet. It crazes where
> thick.
>
> The photo is here but there is not much to see for a transparent glaze te=
st.
> http://www.flickr.com/photos/yamerica/5792388852/in/photostream
>
> What is the next step? I am guessing I need to add a secondary flux
> (cheap one, not a frit) I'm thinking some calcium like Wollastonite
> because I want to add more silica as well. (It's already cloudy,
> whiting would be too gassy, I reckon) I don't know how much I need to
> add as I don't have analysis for this. Should I start with 60 gm (half
> part) and go from there?
>
> Thanks in advance for your comments
> May
>
> --
> http://twitter.com/MayLuk
> http://www.ceramicsbrooklyn.com/
>
>
Ron Roy on fri 3 jun 11
Hi May,
I used a ball clay instead of bmix to calculate - looks like the
alumina is high.
I also retotaled the recipe so I could work in percent.
I reduced the 3195 by half and added that amount of 3134 - which has
no alumina and that helped a lot - got the expansion to a much better
level. Still too much alumina though. I then added 5% wollastonite and
reduced the silica by the same amount.
I also did a second recipe raising the wollastonite to 10% and
reducing the silica to 10%. See below.
There is still a lot of frit so there may be some running so protect
your shelves.
A short 5 part line blend of those two should tell you a lot.
Your original
CUSTER SPAR................. 20.00
F3195....................... 40.00
BELL DARK................... 20.00
SILICA...................... 20.00
=3D=3D=3D=3D=3D=3D=3D=3D=3D
100.00
CaO 0.52* 4.58
MgO 0.01* 0.09
K2O 0.14* 2.14
Na2O 0.32* 3.17
Fe2O3 0.01 0.25
TiO2 0.02 0.31
B2O3 0.88 9.61
Al2O3 0.87 14.05
SiO2 6.95 65.79
Si:Al: 7.96
SiB:Al: 8.96
Thermal Expansion: 286.26
Formula Weight: 633.70
CUSTER SPAR................. 20.00
F3195....................... 20.00
F3134....................... 20.00
BELL DARK................... 20.00
SILICA...................... 15.00
Wollastonite................ 5.00
=3D=3D=3D=3D=3D=3D=3D=3D=3D
100.00
CaO 0.63* 8.62
MgO 0.01* 0.14
K2O 0.09* 2.15
Na2O 0.27* 4.03
Fe2O3 0.01 0.27
TiO2 0.02 0.31
B2O3 0.56 9.54
Al2O3 0.47 11.72
SiO2 4.30 63.23
Si:Al: 9.17
SiB:Al: 10.37
Thermal Expansion: 384.20
Formula Weight: 408.28
CUSTER SPAR................. 20.00
F3195....................... 20.00
F3134....................... 20.00
BELL DARK................... 20.00
SILICA...................... 10.00
Wollastonite................ 10.00
=3D=3D=3D=3D=3D=3D=3D=3D=3D
100.00
CaO 0.67* 10.79
MgO 0.02* 0.22
K2O 0.08* 2.15
Na2O 0.23* 4.05
Fe2O3 0.01 0.28
TiO2 0.01 0.31
B2O3 0.48 9.55
Al2O3 0.41 11.82
SiO2 3.55 60.85
Si:Al: 8.75
SiB:Al: 9.94
Thermal Expansion: 419.72
Formula Weight: 349.97
RR
Quoting May Luk :
> Hello all;
>
> I have loads of B-mix clay scrap from my handbuilding. My original
> workflow plan was to use the scrap clay for slipcasting and B-mix is
> not made for that. Even though I use the scraps to make color slip for
> painting. I still have lots of B-mix left. I want to make a glaze with
> the B-mix to use it up. It does make a nice glaze slop without
> bentonite or veegum because of its gel-like consistency.
>
> This is my initial glaze recipe:
> Custer Feldspar_______120 gm (1 part)
> Frit 3195_____________240 gm (2 part)
> B-mix _______________120 gm (1 part)
> Silica________________120 gm (1 part)
>
> It is cone 6 oxidation. The finish test is not mature and mildly
> orange-peeled. It's cloudy and not transparent yet. It crazes where
> thick.
>
> The photo is here but there is not much to see for a transparent glaze te=
st.
> http://www.flickr.com/photos/yamerica/5792388852/in/photostream
>
> What is the next step? I am guessing I need to add a secondary flux
> (cheap one, not a frit) I'm thinking some calcium like Wollastonite
> because I want to add more silica as well. (It's already cloudy,
> whiting would be too gassy, I reckon) I don't know how much I need to
> add as I don't have analysis for this. Should I start with 60 gm (half
> part) and go from there?
>
> Thanks in advance for your comments
> May
>
> --
> http://twitter.com/MayLuk
> http://www.ceramicsbrooklyn.com/
>
May Luk on fri 17 jun 11
Hello Ron and friends;
While I'm waiting for a bisque firing so that I can get more tiles to
make the line blend test you suggested for a basic transparent glaze,
I have been thinking about your statement about "high alumina"....
So I look up high alumina glaze and see what I can get out of it. I
opened up to page 56 of Oriental Glazes by Michael Bailey. I think
this is a good opportunity to explore some semi-transparent satin and
satin matts.
Since I last posted, I have add into my glaze A with half part of
Wollastonite. (just because I said I would do it, and it's easy to
make a progressive test)
The glaze recipe "B" from the original progressive test is now:
>> Custer Feldspar_______120 gm (1 part)
>> Frit 3195_____________240 gm (2 part)
>> B-mix _______________120 gm (1 part)
>> Silica________________120 gm (1 part)
>> Wollastonite___________60 gm (0.5 part)
The test tile is definitely less orange peel and shinier. It is not a
mature glaze yet. For the purpose of creating a satin matt, what
should I add in next? Talc? Dolomite?
Thanks in advance for any input from anybody!
May
Brooklyn NY
On Fri, Jun 3, 2011 at 10:33 PM, wrote:
> Hi May,
>
> I used a ball clay instead of bmix to calculate - looks like the alumina =
=3D
is
> high.
>
>>
>> I have loads of B-mix clay scrap from my handbuilding. My original
>> workflow plan was to use the scrap clay for slipcasting and B-mix is
>> not made for that. Even though I use the scraps to make color slip for
>> painting. I still have lots of B-mix left. I want to make a glaze with
>> the B-mix to use it up. It does make a nice glaze slop without
>> bentonite or veegum because of its gel-like consistency.
>>
>> This is my initial glaze recipe:
>> Custer Feldspar_______120 gm (1 part)
>> Frit 3195_____________240 gm (2 part)
>> B-mix _______________120 gm (1 part)
>> Silica________________120 gm (1 part)
>>
>> It is cone 6 oxidation. The finish test is not mature and mildly
>> orange-peeled. It's cloudy and not transparent yet. It crazes where
>> thick.
>>
>> The photo is here but there is not much to see for a transparent glaze
>> test.
>> http://www.flickr.com/photos/yamerica/5792388852/in/photostream
>>
>> What is the next step? I am guessing I need to add a secondary flux
>> (cheap one, not a frit) I'm thinking some calcium like Wollastonite
>> because I want to add more silica as well. (It's already cloudy,
>> whiting would be too gassy, I reckon) I don't know how much I need to
>> add as I don't have analysis for this. Should I start with 60 gm (half
>> part) =3DA0and go from there?
>>
>> Thanks in advance for your comments
>> May
>>
>
>
>
--=3D20
http://twitter.com/MayLuk
http://www.ceramicsbrooklyn.com/
Ron Roy on sun 19 jun 11
Hi May -
Hhe alumina is still high which explains why it's not melting
properly. Take a look at some cone 6 limit formulas to get some idea
how much alumina should be there for a good melt.
Calculating out the clears in our book will give you a good idea what
that number should be - also note that a silica/alumina ration of 10
to 1 is better for clear shiny glazes - because you have boron in that
number can be lower.
Doubling the wollastonite might do it but - the expansion is still low
and could be a problem - remember - Getting in some more KNaO will
help raise the expansion and help the melt but keep an eye on the
alumina when adding Neph Sy or spar.
RR
Quoting May Luk :
> Hello Ron and friends;
>
> While I'm waiting for a bisque firing so that I can get more tiles to
> make the line blend test you suggested for a basic transparent glaze,
> I have been thinking about your statement about "high alumina"....
>
> So I look up high alumina glaze and see what I can get out of it. I
> opened up to page 56 of Oriental Glazes by Michael Bailey. I think
> this is a good opportunity to explore some semi-transparent satin and
> satin matts.
>
> Since I last posted, I have add into my glaze A with half part of
> Wollastonite. (just because I said I would do it, and it's easy to
> make a progressive test)
>
> The glaze recipe "B" from the original progressive test is now:
>>> Custer Feldspar_______120 gm (1 part)
>>> Frit 3195_____________240 gm (2 part)
>>> B-mix _______________120 gm (1 part)
>>> Silica________________120 gm (1 part)
>>> Wollastonite___________60 gm (0.5 part)
>
> The test tile is definitely less orange peel and shinier. It is not a
> mature glaze yet. For the purpose of creating a satin matt, what
> should I add in next? Talc? Dolomite?
>
> Thanks in advance for any input from anybody!
ivor and olive lewis on mon 18 jul 11
Dear May Luk ,
Without an analysis for your B-Mix this is a pretty sour lemon to sample. N=
o
chance of nutting out the Unity Formula.
I have several good opaque white satin mat glazes that mature at Orton Cone
8.using Soda Felspar, Wollastonite, Talc and Kaolin. My suggestion would be
to substitute you B-Mix for the Kaolin then line blend this mixture 5
percent increments of your frit to bring the maturity temperature down to
Orton Cone 6. You will notice I use far more Magnesium and Calcium Silicate=
s
to encourage opacity and recrystallisation. I have eliminated the Dolomite,
an unnecessary distraction. I would avoid using Alumina to get a matt
texture.
Soda Felspar 57.14
Kaolin 3.57
Talc 17.85
Wollastonite 21.42
Regards,
Ivor Lewis,
REDHILL,
South Australia
Ron Roy on wed 20 jul 11
Hi May,
G200 is a potash spar by the way.
The cloudy glaze is either bubbles or crystals I suspect - you can
check with a magnifying glass - probably crystals if you slow cooled -
they may look like stars or snow flakes.
The cure for both crystals, bubbles and getting a semi matte surface
is more alumina - so increasing the bmix is probably the way to go -
keep an eye on expansion as you add it.
If you add a material to your materials table you will get more
accurate results - like a cone 6 porcelain for instance 25% each of
ball, kaolin, silica and neph sy.
RR
Quoting May Luk :
> Hello all (and Ron)
>
> Since I last test this glaze, I literally kicked the bucket and
> spilled the glaze on the floor. I was not able to continue my
> progressive test. Nevertheless, I was going to take on another
> direction and try to make a high alumina, dolomite satin glaze with my
> surplus B Mix scrap instead.
>
> Here's the new test:
>
> BG3 - cone 6 oxidation
> Soda Spar (G200)____300 gm
> Frit 3134_____________600 gm
> Wollastonite__________200 gm
> Dolomite_____________150 gm
> Talc_________________50 gm
> B Mix________________300 gm
> Silica________________300 gm
>
> For an intended satin matt, it is shiny. I might be a bit heavy handed
> on the Wolly. It is shiny, transparent where thin and white cloudy
> (still shiny) where thick. I don't know which unmelted oxide is in the
> cloudy area. The firing schedule included a slow cool ramp. The glaze
> slope is very nice to handle without any additional gum or bentonite.
>
> I am going to look up satin matt anaylysis to make adjustment. Please
> comment if you see fit.
>
> The test tile here:
> http://www.flickr.com/photos/yamerica/5946807242/in/photostream
> http://www.flickr.com/photos/yamerica/5946251971/in/photostream/
>
> Rough analysis here using Bell Dark in place of missing B Mix analysis
> (Glazemaster)
> http://www.flickr.com/photos/yamerica/5946300653/in/photostream/
>
> Thank you
> May
> Brooklyn NY
>
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