J. Creeggan on thu 2 oct 97
Hi everyone!
To get right to the point, has anyone ever had a problem with ilmenite
changing the glaze colour drastically?
I've been using a rutile blue glaze from the internet database called
"moonlight". I've been firing it since last January (probably 15
different firings) with fairly consistent results. It comes out
purplish/bluish/pink and breaks goldish yellow.
I just mixed a new batch with some new chemicals and it came out with a
lot of the same qualities but the purplish/pink is brown. By doing some
additional tests, (my first thought was the rutile, but no) I narrowed
it down to the ilmenite. (2.04% in the recipe) It's odd though because I
haven't heard of ilmenite changing before and also, I have mixed
different batches of the glaze 3 times with different batches of
ilmenite and I had always received consistent results.
Please help! I've just received a lot of orders in this glaze and I'm
desperate.
Thanks in advance,
Jennie in Fort McMurray
Sheryl VanVleck on fri 3 oct 97
I have the Potter's Palette by Constant & Ogden, and they state that you may
need to modify the ilmenite by an addition of spodumene to assist in
maintaining a color response. However, they are speaking of alkaline glazes
and I'm not sure that is pertinent here.
Liz Dodge on sat 4 oct 97
I had a problem with moon light turning brown once, but it turned out I had a
strange batch of Cornwall stone. Have you changed your clay body... it does
turn orange/brown on darker clays. Iimenite being a similar type of variable
material as rutile, I suppose it could have the same unpredictability
problems.
If you can't solve the problem easily, you could use a rutile blue that is
very similar in appearance to moonlight call Opal blue:
Opal Blue ^10 reduction
Ingredient Percentage
Neph Sy 33.87
Dolomite 16.32
zinc ox 2.38
whiting 2.97
kaolin 5.64
flint 34.06
rutile 4.77
This is a similarly georgeous glaze, a little bluer than moonlight and a
little less "grainy" but similar enough and lovely enough your customers will
probably be just as happy.
Liz Dodge
Berkeley, CA
Original message:
has anyone ever had a problem with ilmenite
changing the glaze colour drastically? I've been using a rutile blue glaze
from the internet database called
"moonlight". . . just mixed a new batch with some new chemicals and it came
out with a lot of the same qualities but the purplish/pink is brown.
Jennie in Fort McMurray
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