Hank Ray on mon 21 dec 98
Hey there....
Glaze gods
Here is a glaze that is a glossy black breaking brown....
with all the limit formulas i have checked it is over supplyed with silica....
but this glaze is very much glossy...... i am guessing the RIO has something
to do with it...
i was hoping some one could explain it.....
Kona F-4 ........42.23
Whiting...........11.52
EPK................6.72
Flint................32.63
RIO.................6.14
Cobalt Carb.....0.77
---------
100.01
peace... on ... earth...
Pete... in oklahoma..
Helllll@aol.com
Grimmer on tue 22 dec 98
Hank,
This appears to be a balanced glaze at cone 10, both with RIO included in
unity for reduction and without. The upper limit for SiO2 given in Insight's
table is 5 molecular equivalents, and this glaze has about 4 with reduction
and 4.7 without, so no problem there, but there is a lot there to be melted.
The expansion is kind of high, so it will craze on lots of bodies. Fe2O3 can
bring the expansion of a glaze up pretty quickly, and there's no shortage
here. The expansion is considerably lower when you take the iron out, but
then you have a blue glaze . What with the fluxing power of all that
iron, you could probably add considerable amounts of flint to the glaze and
still get a good, glossy melt. So, yes the iron has something to do with it.
You might try balancing the added silica with some alumina in the form of
kaolin to help application and prevent settling if that's a problem, but
I've found that lots of Red Iron seems to do a pretty good job of suspending
a glaze. Does anyone know if that's more due to fine particle size or pH?
Here's the numbers I get with Insight when Fe2O3 is included in unity:
3-D Black cone 10 R
=================
F-4 FELDSPAR........ 42.23 42.23%
WHITING............. 11.52 11.52%
EPK KAOLIN.......... 6.72 6.72%
FLINT............... 32.63 32.63%
IRON OXIDE RED...... 6.14 6.14%
*Cobalt Carb......... 0.77 0.77%
========
100.01
CaO 0.58* 9.06%
MgO 0.00* 0.03%
K2O 0.08* 2.23%
Na2O 0.18* 3.17%
TiO2 0.00 0.03%
Al2O3 0.41 11.76%
P2O5 0.00 0.02%
SiO2 4.01 67.08%
Fe2O3 0.15* 6.62%
Cost/kg 0.68
Si:Al 9.68
SiB:Al 9.68
Expan 7.23
Just for grins, here's a variation with the alumina nearly maxed out and the
ratio held the same. Will this melt at C10?
Untitled Recipe 1
=================
F-4 FELDSPAR........ 42.23 36.09%
WHITING............. 11.52 9.85%
EPK KAOLIN.......... 12.72 10.87%
FLINT............... 43.63 37.29%
IRON OXIDE RED...... 6.14 5.25%
*Cobalt Carb......... 0.77 0.66%
========
117.01
CaO 0.59* 8.10%
MgO 0.00* 0.03%
K2O 0.08* 1.92%
Na2O 0.18* 2.71%
TiO2 0.00 0.05%
Al2O3 0.49 12.14%
P2O5 0.00 0.03%
SiO2 4.71 69.32%
Fe2O3 0.15* 5.69%
Cost/kg 0.61
Si:Al 9.69
SiB:Al 9.69
Expan 6.79
Keep Warm!
steve grimmer
marion illinois
----------
>From: Hank Ray
>To: CLAYART@LSV.UKY.EDU
>Subject: 3-D Black cone 10 R
>Date: Mon, Dec 21, 1998, 2:12 PM
>
>----------------------------Original message----------------------------
>Hey there....
>Glaze gods
>Here is a glaze that is a glossy black breaking brown....
>
>with all the limit formulas i have checked it is over supplyed with
silica....
>but this glaze is very much glossy...... i am guessing the RIO has
something
>to do with it...
>i was hoping some one could explain it.....
>Kona F-4 ........42.23
>Whiting...........11.52
>EPK................6.72
>Flint................32.63
>RIO.................6.14
>Cobalt Carb.....0.77
> ---------
> 100.01
>
>
>
>peace... on ... earth...
>Pete... in oklahoma..
>Helllll@aol.com
Craig Martell on tue 22 dec 98
>----------------------------Original message----------------------------
>Hey there....Glaze gods
Hey Pete:
Although I'll try to make some worthwhile comments about this glaze I have
to tell you that I'm not very religeous so the above may not apply to me.
>with all the limit formulas i have checked it is over supplyed with
silica....
>but this glaze is very much glossy...... i am guessing the RIO has
something to do with it...
I ran the glaze through Insight and I came up with a bit more than 5.0 moles
of silica in the RO unity and that's really not what I would call
oversupplied. The cone 10 limits are 3.0 to 5.0 molecular parts and you are
close to the upper limit. This glaze should be very durable.
If you want to see what the iron oxide is doing, make the glaze without it
and see what sort of melt you get. You can also make a fusion test of the
F-4 and whiting and see what the rate of fusion is. I would think that the
soda spar and whiting are very active melters at cone 10 R and would
probably fuse this glaze without the iron and cobalt. Cobalt has a bit of
fluxing action as well but I can't give any comparison with the iron.
Also, something we don't think about all that much is the action that
alumina and silica have on each other. In correct proportions, they will
actually help flux the glaze. I don't know if that's what is happening with
your glaze. One can take a flux mixture that isn't fusing to a clear glassy
melt and blend in alumina and silica (Ian Currie type biaxial blends work
really well for this) and improve the melt, sometimes to a very glassy
state.
Craig Martell in Oregon
Ron Roy on wed 23 dec 98
Hey Hank - don't be calling me a glaze God - there ain't no such a thing -
take about a hex!
Here is you recipe calculated two ways. Remember that Fe2O3 is not much of
a flux but reduced to FeO it a big time flux - so in the 2nd calculation
it's included in with the fluxes and makes quits a difference. My software
does not make the transition properly - there will be less FeO because some
of the Fe2O3 will be gone (will someone else do this properly?)
As you can see the molecular formula within the limits when the iron is
included.
The ratio - being over 10 indicates a shiny glaze.
You will find it intesting to do a line blend - running the iron out 1% at
a time - should be a celadon with 1 to 2% iron.
Your glaze as if fired in oxidation
-----------------
F4 SPAR............. 42.23
WHITING............. 11.52
EPK................. 6.72
SILICA.............. 32.63
RED IRON OX......... 6.14
*coblt carb.......... .77
----------
Total.........................100.01
FORMULA & ANALYSIS
------------------
*CaO........ .64 7.60%
*MgO........ .00 .04%
*K2O........ .11 2.21%
*Na2O....... .24 3.13%
Fe2O3...... .20 6.71%
TIO2....... .00 .02%
AL2O3...... .54 11.64%
SiO2....... 5.44 68.64%
P2O5....... .00 .01%
RATIO 10.02
EXPAN 461.19
WEIGHT 475.14
Your glaze with iron oxide in unity with fluxes.
-----------------
F4 SPAR............. 42.23
WHITING............. 11.52
EPK................. 6.72
SILICA.............. 32.63
RED IRON OX......... 6.14
*coblt carb.......... .77
----------
100.01
FORMULA & ANALYSIS
------------------
*CaO........ .54 7.60%
*MgO........ .00 .04%
*K2O........ .09 2.21%
*Na2O....... .20 3.13%
*Fe2O3...... .17 6.71%
TIO2....... .00 .02%
AL2O3...... .45 11.64%
SiO2....... 4.53 68.64%
P2O5....... .00 .01%
RATIO 10.02
EXPAN 461.19
WEIGHT 396.23
>----------------------------Original message----------------------------
>Hey there....
>Glaze gods
>Here is a glaze that is a glossy black breaking brown....
>with all the limit formulas i have checked it is over supplyed with silica....
>but this glaze is very much glossy...... i am guessing the RIO has something
>to do with it...
>i was hoping some one could explain it.....
>Kona F-4 ........42.23
>Whiting...........11.52
>EPK................6.72
>Flint................32.63
>RIO.................6.14
>Cobalt Carb.....0.77
> ---------
> 100.01
>peace... on ... earth...
>Pete... in oklahoma..
>Helllll@aol.com
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
Jim Brooks on fri 25 dec 98
Ron..please do us a favor and alter this glaze to fire at cone 6.. Thanks
Ron Roy on sat 26 dec 98
Hi Jim,
I am guessing you want it for cone 6 oxidation - if it's for reduction I
will have to do it again.
This first recipe is just the first of what will probably be several to get
a stable, durable black at cone 6 oxidation - anyone who wants to do the
tests will learn something about developing glazes for cone 6. All you have
to do to get the next in the series is post the results to the list - fired
with a cone beside it, what kind of clay - how long the firing from red
heat to cone 6 half down, how long soaked, cone bend plus frozen and dipped
in boiling water 3 times and report any fit problems.
RR c6 black #1 sieve 2 times through 80 mesh. Should be good under and over
other glazes but when layering - do some testing first to see if running is
going to be a problem. Many of the glazes we are using are unbalanced and
when they are melted with a balanced glaze they may over flux it.
-----------------
F4 SPAR...................22.00
WHITING...................9.00
TALC..........................2.00
F3134........................21.00
EPK............................17.00
SILICA......................29.00
RED IRON OX........10.00
Cobalt Carb..............1.00
----------
Total......................111.00
FORMULA & ANALYSIS
------------------
*CaO...............0.52.......9.43%
*MgO..............0.05.......0.62%
*K2O...............0.04......1.09%
*Na2O............0.18......3.57%
Fe2O3.............0.19......9.83%
TIO2................0.00......0.05%
*B2O3............0.21......4.69%
AL2O3............0.32...10.37%
SiO2...............3.14....60.32%
P2O5..............0.00......0.02%
RATIO 9.89 - Original ratio is 10.02
EXPAN 464.53 - Original expansion (my scale) is 461.19
WEIGHT 312.40
If anyone needs it with a different spar and/or a different frit let me
know which ones you have. Ferro frit 3124 is not good for this because it
has too little boron and the alumina will limit the amount of raw clay in
the bucket. Ferro 3278 or an equivalent will work well.
Substitution frits for Ferro 3134 are: Pemco P-54, Hommel 14, Fusion F-12
and GF 111.
>----------------------------Original message----------------------------
>Ron..please do us a favor and alter this glaze to fire at cone 6.. Thanks
3D Black - cone 10 reduction.
Kona F-4 ........42.23
Whiting...........11.52
EPK................6.72
Flint................32.63
RIO.................6.14
Cobalt Carb.....0.77
---------
100.01
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
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