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amaco velvet underglaze at c6

updated tue 24 nov 09

 

Dennis Gerasimov on sat 21 nov 09


Greetings clay folks!

I have agreed to fire some pieces for a relative of mine who no longer
has access to a kiln. I fire at c6, so she got some c6 clay. She works
with Amaco Velvet underglazes. We have noticed that some colours,
particularly green, come out pretty dull. Sometimes almost grey. Amaco
says on their web site that Velvet underglazes are good to c6. I am
wondering if it could be my glaze, clay body, firing schedule, or is it
a stretch of imagination that these undergazes should work at c6?
Anyone has any experience with Amaco Velvet at c6?

She is using Standard #153 clay. She paints the sculptures (or test
tiles), then I bisque to c06.

I have tried a couple of transparent glazes so far: the 5x20 (G1214M)
and the BG1 from the Glazes Cone 6 book by Michael Bailey - the result
is identical.

The firing schedule is pretty straight forward: fast to c6 (4 hours),
fast down to 1000C (25 min), slow to 500C (4 hours), fast to RT (2 - 3
hours).


Any suggestions would be greatly appreciated!
Dennis

marci and rex on sun 22 nov 09


At 08:49 PM 11/21/2009, Dennis Gerasimov wrote:
>Greetings clay folks!
>
>I have agreed to fire some pieces for a relative of mine who no longer
>has access to a kiln. I fire at c6, so she got some c6 clay. She works
>with Amaco Velvet underglazes. We have noticed that some colours,
>particularly green, come out pretty dull. Sometimes almost grey. Amaco
>says on their web site that Velvet underglazes are good to c6.


I use Velvet Underglazes on a cone 6 porcelain clay ( Laguna
Frost ) usually with a clear glaze over it once-fired.
I have good results with most of the Velvet U/gs but some
DO change color and some disappear ... I m pretty sure if
you read the info about the u/g s it says that many of them
can be fired to cone 6 .... ( not all ) ... The website says :"
However, some colors may change, fade away partially, or entirely
disappear when used at mid range or high temperatures." They have
a pdf file on the website showing what the colors should
look like fired to cone 5 and cone 10 ...but Im sure its
a case of " your results may vary ". http://www.amaco.com/pdfs/458-1.p=
df
I did a test piece of all
of my u/g colors with glaze and no glaze to cone 6 to
see what would happen.. Thats the only way to tell for
sure what will work with the clay and glazes your using..
marci
www.ppio.com

Snail Scott on sun 22 nov 09


On Nov 21, 2009, at 8:49 PM, Dennis Gerasimov wrote:
> ...Amaco says on their web site that Velvet underglazes are good to
> c6...


Yes, but only some of them are color-true, and they can
also be affected by the composition of the clear glaze if
you use one. TEST!!!!

Also, I noticed that my local supplier has a new Velvet
chart showing what each one looks like at ^6. It's
about what you'd expect - the reds, purples, and such
are the most altered by the higher temperatures.

I've never understood people's devotion to Velvets at
^6. They were developed (when Reward owned the
line) as low-fire colors. Amaco's LUG line is much more
color-true and opaque at ^6.

-Snail

Carole Fox on mon 23 nov 09


I have used Amaco velvet underglazes at ^6 on various clay bodies, brown=3D=
20=3D

and white. As others have previously stated, some colors do fade out. I=
=3D
=3D20
have never had a problem with greens, however. I have used Hunter Green,=
=3D
=3D20
Leaf Green, and Cactus Green. All fire to pleasing shades of green. I u=
=3D
sually=3D20
cover with Laguna MS29 Clear Bright glaze.

Carole Fox
Dayton, OH