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vs: could it be the rutile?

updated thu 21 jun 01

 

Alisa og Claus Clausen on wed 20 jun 01


Dear Ababi,

When I was first noticing Cobalt greens in some of my glazes, I asked =
the question to clayart was it the Dolomite (magnesium) that acted as a =
catalyst for the greens. To paraphrase the good information I received =
from Hank;

To obtain cobalt green, magnesium is neither required nor be excluded. =20
Titania is required (that is the key)
from rutile or titanium oxide.

Test 1% cobalt plus 4 rutile

and

1%cobalt plus 4 titanium.

Paint stripes on all of your glazes and you will see a variety of =
greens.

Bev's Smile is the glaze Hank sent also. It comes from the time his =
wife was working also on obtaining cobalt greens.
cone 9-10 ox. or redux.

42 Custer spar (Buckingham or Kingman or g200)
20 Whiting
25 EPK
10 Silica

Add
3 Rutile or more TiO2
1.5 Cobalt carb.

The glaze I made for a rutile green is cone 6, oxidation

Cobalt green mat

48 Neph. Syenite
27 Dolomite
6 Wollastonite
20 Ball Clay

Add
1 % cobalt ox.
5 rutile

results in a matt, light green, with streaking but not dripping.

Best regards,
Alisa in Denmark



> Could it be the rutile?
> There are several beautiful blue glazes with more rutile than cobalt. =
When I
> apply them on the bare piece I get green. When apply them above low =
alumina
> glaze I get blue. I use it lately to get more coloring from the same
> glaze.Like in this tile where I applied both ways!
> http://members4.clubphoto.com/ababi306910/UTILITY__ClayArt/ The last
> slide.
>=20
> This is really nice.
> Is this the "normal way" or it is because of "my" rutile?
>=20
> Ababi
>=20
> =
_________________________________________________________________________=
_____
> Send postings to clayart@lsv.ceramics.org
>=20
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>=20
> Moderator of the list is Mel Jacobson who may be reached at =
melpots@pclink.com.

Ababi on wed 20 jun 01


I wondered why many glazes called xxx blue or yyy blue with rutile. I always
get them green except when I make this trick of applying underneath them a
low alumina glaze.
I wondered because somehow if the rutile here is the best quality if there
is such a thing , I thought there might be a different rutile that
is not so active! Of coarse I can reduce the rutile but I Chang the glaze!
I got an advise to reduce the alumina, I will try this first. It might be
that our European materials are a little different in their alumina
contents.
By the way, I got yesterday the Penland Glaze Book. It is a very nice book,
made like a notebook that someone would make for his own use, kind of fresh
looking. Some of the glazes I saw before, for sure an appetizer.I think I
might try some ^10 in ^6 at least one glaze that I had tested last week
was there as ^10.
About this letter, I shall keep it in my GLAZE file, I have to mix about
30 test tonight or tomorrow. the main subject. the effect of high magnesia
glazes on different oxides besides cobalt.
Ababi Sharon in Kibbutz Shoval - Israel- glaze addict
http://members4.clubphoto.com/ababi306910/
ababisha@shoval.ardom.co.il
http://www.milkywayceramics.com/cgallery/asharon.htm
http://www.israelceramics.org/


Hello John.
Thank you very much for the book. I am sure it will help me to understand
better, the ceramic doing.
The ^10 glazes will give me hints, I might also try some of them the way
they are.
One aspect, of ceramic software, that people might not see as a main point,
is the possibility to take strange names like: "Alberta slip" or Albany
slip" which I never saw, and turn them into a correct glaze.
I did not find the low fire glazes you offered in your site, I think they


----- Original Message -----
From: "Alisa og Claus Clausen"
To:
Sent: Wednesday, June 20, 2001 11:16 AM
Subject: Vs: Could it be the rutile?


Dear Ababi,

When I was first noticing Cobalt greens in some of my glazes, I asked the
question to clayart was it the Dolomite (magnesium) that acted as a catalyst
for the greens. To paraphrase the good information I received from Hank;

To obtain cobalt green, magnesium is neither required nor be excluded.
Titania is required (that is the key)
from rutile or titanium oxide.

Test 1% cobalt plus 4 rutile

and

1%cobalt plus 4 titanium.

Paint stripes on all of your glazes and you will see a variety of greens.

Bev's Smile is the glaze Hank sent also. It comes from the time his wife
was working also on obtaining cobalt greens.
cone 9-10 ox. or redux.

42 Custer spar (Buckingham or Kingman or g200)
20 Whiting
25 EPK
10 Silica

Add
3 Rutile or more TiO2
1.5 Cobalt carb.

The glaze I made for a rutile green is cone 6, oxidation

Cobalt green mat

48 Neph. Syenite
27 Dolomite
6 Wollastonite
20 Ball Clay

Add
1 % cobalt ox.
5 rutile

results in a matt, light green, with streaking but not dripping.

Best regards,
Alisa in Denmark



> Could it be the rutile?
> There are several beautiful blue glazes with more rutile than cobalt. When
I
> apply them on the bare piece I get green. When apply them above low
alumina
> glaze I get blue. I use it lately to get more coloring from the same
> glaze.Like in this tile where I applied both ways!
> http://members4.clubphoto.com/ababi306910/UTILITY__ClayArt/ The last
> slide.
>
> This is really nice.
> Is this the "normal way" or it is because of "my" rutile?
>
> Ababi
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.

____________________________________________________________________________
__
Send postings to clayart@lsv.ceramics.org

You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/

Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.