Sarah House on sun 14 jun 98
Hello all, I was hoping for help with a problem concerning Amaco Velvet
underglazes. Are current procedures-apply two to three coats of
underglaze to bone dry tiles, bisque to cone 05, apply two to three
coats of opulence clear glaze, fire to cone 6. The problem-the glaze has
a cloudy look that opon close look is actually tiny bubbles. It feels
like we've tried everything, fewer and thinner coats of glaze and
underglaze, slower firing, soaking, applying underglaze to leather hard
and bisqued ware. Our next sourse of action is to bisque a cone higher.
Obviously a lower glaze firing temp might help, but we would like to
keep the strength of what we have, and the ability to mix loads of tiles
with functional ware. Does anyone have any other suggestions, and as a
last resort, can any one suggest another type of underglazes that they
have tried?
Please respond to skhouse@mailexcite.com
Thank you,
Sarah House
cyberscape on mon 15 jun 98
Sarah,
Velvet underglazes were designed to be used without a covering glaze.
Perhaps you should try Amaco's regular underglazes. You may have better
luck. Also, try applying the underglaze to leather hard clay and
bisquit firing to ^04.
Harvey Sadow
> Date: Sun, 14 Jun 1998 00:10:05 EDT
> From: Sarah House
> Subject: velvet underglazes
>
> ----------------------------Original message----------------------------
> Hello all, I was hoping for help with a problem concerning Amaco Velvet
> underglazes. Are current procedures-apply two to three coats of
> underglaze to bone dry tiles, bisque to cone 05, apply two to three
> coats of opulence clear glaze, fire to cone 6. The problem-the glaze has
> a cloudy look that opon close look is actually tiny bubbles. It feels
> like we've tried everything, fewer and thinner coats of glaze and
> underglaze, slower firing, soaking, applying underglaze to leather hard
> and bisqued ware. Our next sourse of action is to bisque a cone higher.
> Obviously a lower glaze firing temp might help, but we would like to
> keep the strength of what we have, and the ability to mix loads of tiles
> with functional ware. Does anyone have any other suggestions, and as a
> last resort, can any one suggest another type of underglazes that they
> have tried?
> Please respond to skhouse@mailexcite.com
> Thank you,
> Sarah House
Arlene Nadel on tue 16 jun 98
Dear Sarah, I too use Amaco under-
glazes and have had lots of
frustrations. I use them on
bone dry ware, bisque ^o4 then I
use LG10 the pink colored clear
glaze and fire to ^06 or ^05.
Sometimes it's beautiful and some-
times I get crawling. It's a real
frustration for me. I was a paint
er first and am not patient with
all this unpredictabiliy. However
I am so hooked on working with clay
that I refuse to give up. Some
people have recomended using
Dunken clear glaze over the amaco
underglazes, it all seems like a
crap shoot to me.
Lets stay in touch. Arlene
Grace Epstein on wed 17 jun 98
Arlene.
I also use amaco underglazes and have not experienced crawling...just once
this wierd bubbling from under the clear glaze ?!? i like amaco hf 10 clear
glaze over the underglazes...try that...crawling may be too much clear glaze
????
Grace in soggy wet i've seen enough rain CT
Anne W. Bracker on wed 17 jun 98
Dear Sarah,
I have a couple of questions and a couple of possible answers to
your Velvet problem. First, though, I'd like to clear up some confusion
about the use of Velvets. True, they were originally designed by Reward
(which has since been bought out by AMACO) to be used by sculptors to
achieve the velvety look that they have without a clear glaze. However,
many potters use them successfully with a clear glaze on top to make them
dinnerware safe. So many potters use them that way that AMACO actually
makes their Velvet chip chart with a clear glaze over half the chip.
That having been said, here are a few thoughts:
-First, can you tell if the tiny bubbles that you talked about
are a result of the underglaze? Perhaps it is the Clear glaze. Opulence
glazes need to be sieved with a 60 or 80 mesh screen if you buy them dry
and mix them up. (I would also try screening the glaze even if you
bought them premixed)
-Also, what is your aplication of the clear: Brushing, Dipping,
Pouring? If you are brushing the clear, you may need to add glycerine or
some other brushing medium.
-Finally, I would like to add that Velvets were originally
designed to be low-fire glazes, and while most of them are stable at
^5/6, some of the colors are not as successful.
Feel free to contact me privately if you still are having problems.
I know the glaze technicians at AMACO, and at Mid-South Ceramics (the
makers of Opulence glazes) pretty well and I can either contact them for
you or give you the number.
Good Luck!
Cindy Bracker
Bracker's Good Earth Clays, Inc.
1831 E 1450 Road
Lawrence, KS 66044
1 785 841-4750 OFFICE
1 785 841-8142 FAX
1 888 822-1982 ORDER LINE
bracker@midusa.net E-MAIL
"Clay Ain't Dirt"
Dee Clay on wed 17 jun 98
I have fired bisqued to ^04 and then glazed clear with underglazes on top.
Refired to ^06 without any problems.
Hope this helps someone.
Diane in Miami
Phyllis E. Tilton on thu 18 jun 98
This is in response to this and other problems with velvet and other
underglazes. Some answers could surely be found by calling and/or writing to
Amaco. American Art Clay Co., Inc.
4717 W. 16th St.,
Indianapolis, In. 46222
1 800 374-1600
Fax (317)248-9300
Internet Home Page:http://www.amaco.com/
I have used many different Amaco underglazed with little problem-other than
the roses, pinks, and maroons burning out at higher temps.
I sincerely hope this info will help someone.
Phyllis Tilton
Stephen Mills on fri 19 jun 98
Over here on the other side of the pond we use and sell velvets a lot,
they are very popular, and, in our experience trouble free (excepting
some of the colours in Raku post firing reduction). I would suspect the
glaze first.
Steve
--
Steve Mills
Bath
UK
home e-mail: stevemills@mudslinger.demon.co.uk
work e-mail: stevemills@bathpotters.demon.co.uk
own website: http://www.mudslinger.demon.co.uk
BPS website: http://www.bathpotters.demon.co.uk
Phyllis E. Tilton on fri 19 jun 98
This is in response to this and other problems with velvet and other
underglazes. Some answers could surely be found by calling and/or writing to
Amaco. American Art Clay Co., Inc.
4717 W. 16th St.,
Indianapolis, In. 46222
1 800 374-1600
Fax (317)248-9300
Internet Home Page:http://www.amaco.com/
I have used many different Amaco underglazed with little problem-other than
the roses, pinks, and maroons burning out at higher temps.
I sincerely hope this info will help someone.
Phyllis Tilton
Lisa Rosenstreich on tue 23 jun 98
Duncan glaze works well for me over Amaco velvets. I haven't had any problems
and have been working with the combo for the last few months.
good luck.
Anne W. Bracker on fri 26 jun 98
>Cindy:
>
>two questions..........
>
>1) can velvets be applied equally well to
>grreenware and bisque?
>
>2) can velvets be paTCHED AFTER BEING FIRED TO CONE 6
>with no glaze?
>
>thanks
>
>--
>Bob Bruch rsb8@po.cwru.edu
Bob,
Velvet underglazes can be used on bone-dry greenware, or bisque and
generally work very well. As far as patching them, you can just add a
couple drops of the velvet to where it has flaked off and refire it. If
you find that after being fired to Cone 6 the clay is not pourous enough
to accept the Underglaze, try adding some Apt II to the underglaze.
Also, there is something you can do in advance to prevent this. The
flaking comes from shrinkage problems. If you bisque fire a little
hotter, maybe even as high as 02, your clay will have shrunk more when
you apply the velvets, thus reducing the chances of having fit problems.
The discoloration you mentioned has to do with firing the velvets to Cone
6. All the velvet charts show them fired to about 05, and the color will
vary quite a bit at cone 6. Hope this helps.
Cindy Bracker
Bracker's Good Earth Clays, Inc.
1831 E 1450 Road
Lawrence, KS 66044
1 785 841-4750 OFFICE
1 785 841-8142 FAX
1 888 822-1982 ORDER LINE
bracker@midusa.net E-MAIL
"Clay Ain't Dirt"
| |
|
