|
|
|
1 June 2006
I wanted a glaze that would :
So here's what I came up with initially :
Al2O3 0.5
SiO2 3.5
MgO 0.25
CaO 0.5
KNaO 0.25
After playing with this for a bit I arrived at the formula below :
CUSTER SPAR................. 36.80
SILICA...................... 13.40
EPK......................... 11.20
TALC........................ 11.20
AUSI SPOD................... 15.20
STRONT CARB................. 12.30
=========
100.10
The molecular formula differs a bit from my original envelope sketch being :
CaO 0.07*
MnO2 0.00
Li2O 0.14*
MgO 0.29*
K2O 0.14*
Na2O 0.07*
Fe2O3 0.00
TiO2 0.00
Al2O3 0.50
SiO2 3.52
P2O5 0.00
SrO 0.29*
Fluxes are MgO 0.29, KNaO 0.21, SrO 0.29 and Li2O 0.14 plus odds and sods. Silica/Alumina ratio is bang on. COE calculated is 433 which is about what I need for this body.
The sample on the left is the base glaze, the pink tinting coming from copper in the same firing flying around the kiln. The middle one has 5% tin oxide and 0.25% cobalt carbonate. The one on the right has 5% zircopax and 0.5% cobalt carbonate.
So definitely not bad for a first outing but the colour needs work.