Chris and Nissa on tue 9 apr 02
I have looked in the archives and found ideas about additives to make a
glaze brushable. What I'm looking for is methods to brush on decoration
using oxides or such. Currently I do brush work using the base glaze with
red iron oxide 2:1 and watered down to do loose brushwork..ie Chinese
calligraphy. On another glaze I use a commercial glaze watered down to do
brush work. I am trying to move away from commercial glazes for more control
and new colors.
Right now I am trying to do some brush work on some Ron and John cone6
glazes from the book but am having trouble with severe bleeding and nearly
disappearance of the brushwork (using RIO). Anyone experimented with
different oxides etc to get brushwork to stand out...but not scream? Food
safe is an issue. Additionally I would like to make a set of dishes with
wildlife depicted and could use stamps or such..any ideas appreciated.
Thank you,
Chris Koivisto
Duluth, MN
Ron Roy on sat 13 apr 02
Hi Chris,
The glaze that is designed for brush work is on page 109 - called
"Maiolica" for cone 6 - it is a stiff glaze that will not bleed colours -
you can try it with other colours - with and without the opacifier. Best
way to make the colours is to mix em with that glaze (sans opacifier) - you
will have to experiment with the amount of stain to add to the glaze to get
the colour you want - but keep the stain to a minimum if you are going to
use colour on the inside of pots where it can be in contact with food.
Note - the example - we used 7.7 stain to get those dark colours.
You may find adding some tin with the iron will give you better colour -
depending on what you like.
RR
>I have looked in the archives and found ideas about additives to make a
>glaze brushable. What I'm looking for is methods to brush on decoration
>using oxides or such. Currently I do brush work using the base glaze with
>red iron oxide 2:1 and watered down to do loose brushwork..ie Chinese
>calligraphy. On another glaze I use a commercial glaze watered down to do
>brush work. I am trying to move away from commercial glazes for more
control
>and new colors.
>
>Right now I am trying to do some brush work on some Ron and John cone6
>glazes from the book but am having trouble with severe bleeding and nearly
>disappearance of the brushwork (using RIO). Anyone experimented with
>different oxides etc to get brushwork to stand out...but not scream? Food
>safe is an issue. Additionally I would like to make a set of dishes with
>wildlife depicted and could use stamps or such..any ideas appreciated.
>
>Thank you,
>
>Chris Koivisto
>Duluth, MN
Ron Roy
RR #4
15084 Little Lake Road
Brighton
Ontario
Canada - K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Chris and Nissa on sun 14 apr 02
Ron and others,
I did try the Maiolica from the book and it worked great as described with
copper, cobalt, iron brushwork. However, not liking white especially, I
added 6%rutile and 3%iron to the base and got a light tan where thick and
rust where thin that took the brushwork well-used original test batches
w/oxides with no opacifier again. There was iron spotting on the test mug
(500gram batch allows me to use mug as test tile). Iron spotting may be
from not letting the glaze slake at all..sieved and used. Will try again
after sitting today.
I know a stiff glaze is necessary for success but would like a little more
character/color...like you I use rutile a lot to achieve this. I succesfully
used very small amounts of oxides <1%cobalt..do not have any stains. Would
stains be safer? I'll keep testing. Any other ideas appreciated.
Thanks,
Chris
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of Ron Roy
Sent: Friday, April 12, 2002 11:41 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: RR&John Cone 6 Brushwork Methods
Hi Chris,
The glaze that is designed for brush work is on page 109 - called
"Maiolica" for cone 6 - it is a stiff glaze that will not bleed colours -
you can try it with other colours - with and without the opacifier. Best
way to make the colours is to mix em with that glaze (sans opacifier) - you
will have to experiment with the amount of stain to add to the glaze to get
the colour you want - but keep the stain to a minimum if you are going to
use colour on the inside of pots where it can be in contact with food.
Note - the example - we used 7.7 stain to get those dark colours.
You may find adding some tin with the iron will give you better colour -
depending on what you like.
RR
Ron Roy on mon 15 apr 02
Hi Chris,
No I don't think stains are safer - just the opposite because many do not
bother to find out what is in them. I just assumed you used them because
the "painters" usually use them - because they have so many colours to
choose from.
What determins stability is the glaze - and how much stain or colour is
used - given the proper silica and alumina content and how well melted it
is.
Alway better to mix the colour with a stable glaze to help lock it in - but
we still recommend not using overglaze colour where it can contact food
unless tested for metal release - particularly if any toxins are present.
You still don't want the colour changing in use - customers don't think
that is right and I don't blame them.
RR
>I know a stiff glaze is necessary for success but would like a little more
>character/color...like you I use rutile a lot to achieve this. I
succesfully
>used very small amounts of oxides <1%cobalt..do not have any stains. Would
>stains be safer? I'll keep testing. Any other ideas appreciated.
>
>Thanks,
>
>Chris
Ron Roy
RR #4
15084 Little Lake Road
Brighton
Ontario
Canada - K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
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