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subbing for gerstley borate #2

updated tue 3 may 11

 

Ron Roy on sun 1 may 11


4th step - add either talc or dolomite to get some MgO - we need 0.02
mols - when I added the dolomite the B2O3 went down so I also added
more frit.

F4 SPAR..................... 34.90
F3134....................... 35.40 added more
SILICA...................... 25.30
WHITING..................... 5.60
DOLOMITE.................... 1.00 added 1
OM-4........................ 3.60
=3D=3D=3D=3D=3D=3D=3D=3D=3D
105.80

CaO 0.62* MgO 0.02*
K2O 0.06* KNaO .37
Na2O 0.31*
Fe2O3 0.00
TiO2 0.00
B2O3 0.37
Al2O3 0.24
SiO2 3.49

Si:Al: 14.46
SiB:Al: 15.98
Thermal Expansion: 482.55
Formula Weight: 319.77

If I just got the alumina and silica to match up with the original
this would probably be OK - but the CaO is a little high and so is the
KNaO.

I'll take out a little whiting and to lower the CaO and take out a
little spar to lower the KNaO. The KNaO stayed at .37 but the CaO is
right now - trouble is the B2O3 went up so I had to take out some 3134.

F4 SPAR..................... 30.90
F3134....................... 30.40
SILICA...................... 25.30
WHITING..................... 4.10
DOLOMITE.................... 1.00
OM-4........................ 3.60
=3D=3D=3D=3D=3D=3D=3D=3D=3D
95.30

CaO 0.61*
MgO 0.02*
K2O 0.06* KNaO .37
Na2O 0.31*
Fe2O3 0.00
TiO2 0.00
B2O3 0.37
Al2O3 0.26 alumina a little low
SiO2 3.81 silica a little high

Si:Al: 14.86
SiB:Al: 16.31
Thermal Expansion: 460.89
Formula Weight: 340.99

So now the fluxes are as close as needed - the boron is OK - now
adjust the alumna and silica by increasing the clay and decreasing the
silica keeping an eye on silica alumina ratio and expansion.

By the way in both insight and glazemaster you can select my expansion
numbers if you find that more convenient.

So when I add the alumina and decreased the silica I noticed that the
CaO and Boron went down a bit - so I also added a bit more whiting and
frit - then topped up the OM4 and silica so that the si:al ratio and
expansion were close.

All that is left to do is re total to 100 and round off for easier weighing=
.

F4 SPAR..................... 30.90
F3134....................... 30.90
SILICA...................... 23.30
WHITING..................... 4.60
DOLOMITE.................... 1.00
OM-4........................ 6.10
=3D=3D=3D=3D=3D=3D=3D=3D=3D
96.80

CaO 0.61* 10.27
MgO 0.02* 0.26
K2O 0.06* 1.65
Na2O 0.31* 5.71 KNaO =3D .37
Fe2O3 0.00 0.11
TiO2 0.00 0.08
B2O3 0.37 7.64
Al2O3 0.27 8.34
SiO2 3.67 65.94

Si:Al: 13.45 same as original
SiB:Al: 14.79 almost the same as the original
Thermal Expansion: 467.23 very close to the original
Formula Weight: 334.27 again - very close

RR's revision

F4 SPAR..................... 32.00
F3134....................... 32.50
SILICA...................... 24.00
WHITING..................... 4.50
DOLOMITE.................... 1.00
OM-4........................ 6.00
=3D=3D=3D=3D=3D=3D=3D=3D=3D
100.00

CaO 0.61*
MgO 0.02*
K2O 0.06*
Na2O 0.31*
Fe2O3 0.00
TiO2 0.00
B2O3 0.37
Al2O3 0.27
SiO2 3.68


Si:Al: 13.58
SiB:Al: 14.96
Thermal Expansion: 467.59
Formula Weight: 334.56

For those who are interested - there is a convention for listing
materials in a glaze - flux bearing materials first in descending
order of amounts - then clay then silica - like this.

F3134....................... 32.50
F4 SPAR..................... 32.00
WHITING..................... 4.50
DOLOMITE.................... 1.00
OM-4........................ 6.00
SILICA...................... 24.00
=3D=3D=3D=3D=3D=3D=3D=3D=3D
100.00

RR

Lois Sharpe on sun 1 may 11


Ron is Great!

I will test results and post asap!

Thanks Ron

lois



On May 1, 2011, at 4:01 PM, Ron Roy wrote:

> 4th step - add either talc or dolomite to get some MgO - we need 0.02
> mols - when I added the dolomite the B2O3 went down so I also added
> more frit.

Ron Roy on mon 2 may 11


Hi Lois,

I would like you to do the conversion yourself and see how close you can ge=
t.

RR


Quoting Lois Sharpe :

>
>
>
> Ron is Great!
>
> I will test results and post asap!
>
> Thanks Ron
>
> lois
>
>
>
> On May 1, 2011, at 4:01 PM, Ron Roy wrote:
>
>> 4th step - add either talc or dolomite to get some MgO - we need 0.02
>> mols - when I added the dolomite the B2O3 went down so I also added
>> more frit.
>
>