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leather ^6 gb sub?/rr

updated tue 26 mar 02

 

Margaret Barlow on mon 25 mar 02


Hi Chris,

I put your recipe on INSIGHT and here is how it looks with the GB and with
frit 3124. As you can see the flux oxides are close but there is only half
as much boron and more Alumina and silica, so the melt would probably not be
as good and it may not look the same.

Two Recipes: Leather ^6 & Leather ^6 with 3124
====================================
DOLOMITE............ 21.00 21.00
GERS BORATE 9/97.... 10.00
SPODUMENE (Tanko)... 9.00 9.00
CUSTER FELDSPAR..... 27.00 27.00
NEPHELINE SYENITE... 12.00 12.00
EPK KAOLIN.......... 16.00 16.00
WOLLASTONITE........ 5.00 5.00
FRIT 3124........... 10.00
======== ========
100.00 100.00

CaO 0.47* 12.75%w 14.45%m 0.46* 11.76%w 13.35%m
MnO2 0.00 0.01%w 0.00%m 0.00 0.01%w 0.00%m
Li2O 0.05* 0.76%w 1.63%m 0.05* 0.74%w 1.58%m
MgO 0.29* 5.77%w 9.11%m 0.28* 5.10%w 8.06%m
K2O 0.09* 4.14%w 2.80%m 0.09* 3.93%w 2.65%m
Na2O 0.10* 2.92%w 3.00%m 0.11* 3.05%w 3.14%m
Fe2O3 0.00 0.34%w 0.14%m 0.00 0.28%w 0.11%m
TIO2 0.00 0.06%w 0.05%m 0.00 0.05%w 0.04%m
B2O3 0.10 3.27%w 2.99%m 0.05 1.56%w 1.43%m
AL2O3 0.38 18.96%w 11.82%m 0.42 19.26%w 12.03%m
SiO2 1.74 50.96%w 54.00%m 2.00 54.22%w 57.57%m
P2O5 0.00 0.05%w 0.02%m 0.00 0.05%w 0.02%m

COST/KG 1.02 1.34
Si:Al 4.57 4.78
SiB:Al 4.83 4.91
EXPAN557.87 547.87


I then reworked the recipe for you to get it closer to the original, and
used frit 3134 rather than 3124 as 3134 has less silica and alumina and more
boron.

Two Recipes: Leather ^6 & Leather no GB with 3134
=======================================
DOLOMITE............ 21.00 21.50
GERS BORATE 9/97.... 10.00
SPODUMENE (Tanko)... 9.00 8.00
CUSTER FELDSPAR..... 27.00 24.00
NEPHELINE SYENITE... 12.00 8.50
EPK KAOLIN.......... 16.00 21.00
WOLLASTONITE........ 5.00
FRIT 3134........... 13.00
TALC................ 1.50
WHITING............. 2.50
======== ========
100.00 100.00

CaO 0.47* 12.75%w 14.45%m 0.47* 12.88%w 14.56%m
MnO2 0.00 0.01%w 0.00%m 0.00 0.01%w 0.01%m
Li2O 0.05* 0.76%w 1.63%m 0.05* 0.67%w 1.43%m
MgO 0.29* 5.77%w 9.11%m 0.29* 5.79%w 9.11%m
K2O 0.09* 4.14%w 2.80%m 0.07* 3.42%w 2.30%m
Na2O 0.10* 2.92%w 3.00%m 0.11* 3.43%w 3.51%m
Fe2O3 0.00 0.34%w 0.14%m 0.00 0.32%w 0.13%m
TIO2 0.00 0.06%w 0.05%m 0.00 0.07%w 0.06%m
B2O3 0.10 3.27%w 2.99%m 0.10 3.50%w 3.19%m
AL2O3 0.38 18.96%w 11.82%m 0.38 18.80%w 11.69%m
SiO2 1.74 50.96%w 54.00%m 1.75 51.05%w 53.98%m
P2O5 0.00 0.05%w 0.02%m 0.00 0.05%w 0.02%m

COST/KG 1.02 1.47
Si:Al 4.57 4.62
SiB:Al 4.83 4.89
EXPAN557.87 550.62

Of course I did not know exactly what materials you are using and did not
have #6 tile Kaolin on my mdt so it may be a bit off but I think it is
closer than doing a straight sub. The expansion and al/si ratio are also
closer to the original. Of course the proof is in the pudding, so test to
see!

This is the beauty of INSIGHT, being able to adjust the recipe side by side!

Just a word of caution, you probably know that this is not a glaze to be
used on functional ware as the silica is very low. I am not familiar with
this glaze so do not know the colourants that are added but I am sure they
would leach. But then it would probably not be 'leather' if it was a good
functional glaze!!

Hope this helps ....Margaret (hopefully RR will correct any misinformation
I am giving here)


-----Original Message-----
From: Chris and Nissa
To: CLAYART@LSV.CERAMICS.ORG
Date: Monday, March 25, 2002 12:36 PM
Subject: Leather ^6 GB Sub?


>I am going to test following recipe from archives without Gerstly B. and
>subbed 3124 one for one in Insight. How close do you try to match recipes?
>With this small amt. of GB it might be this easy to eliminate..any
>suggestions or comments?
>
>Leather ^6
>21 Dolomite
>10 GB (subbing 3124)
>9 Spodumene
>5 Wollastonite
>27 Custer
>12 Neph Sy
>16 Kaolin (#6 Tile)
>
>Si:Al 4.46 with GB 4.75 w/3124
>Exp 7.84 " 7.65 "
>
>Thank you,
>Chris Koivisto
>
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