Jump to content


Matt Oz

Member Since 16 Dec 2011
Offline Last Active Yesterday, 09:56 PM
-----

Topics I've Started

Comparing Translucency Of Various Kaolins In A Cone 6 Porcelain Body.

09 June 2015 - 01:15 PM

I like to do a lot of experiments formulating translucent cone 6 porcelain bodies and wanted to show the difference in translucency of kaolins.

 

I use this recipe with Grolleg and did not compensate for more refractory kaolin's when mixing up test batches, but from doing various tests in the past these results seem close enough.

 

Cone 6 Porcelain

50 Kaolin

20 Silica 325 mesh

20 G-200 feldspar

4 Talc

1 Veegum T

5 Wollastonite

Add:

2 Frit 3134

2 Bentonite

 

18459416819_d498203eb6_o.jpg

For the test tiles I give the percentage of titanium and iron that the kaolins contain, referencing digitalfire.com with each sample because:

Titanium (TiO2) affects translucency and color.

Iron (Fe2O3) affects color, and less so translucency.

 

Tiles are approximately 3/32" thick (2.4 mm), fired in an electric kiln.

 

Back lit with led bulb.

18649281011_15b6e8c32b_o.jpg

 

Left to right:

New Zealand Halloysite (kaolin)

TiO2___0.05%  2nd lowest

Fe2O3_ 0.25%  Lowest

 

Grolleg

TiO2___0.03%  Lowest

Fe2O3_ 0.70%  2nd highest

 

EPK

TiO2___0.37%  2nd highest

Fe2O3_ 0.79%  Highest

 

#6 Tile

TiO2___1.40%  Highest

Fe2O3_ 0.50%  2nd lowest