Lori Leary on tue 12 dec 00
Hi Jim in Denton,
For various reasons, most of our reduction firing has been at ^6. Here
is a shino with which I have had some good results. Not quite as
luscious as a shino fired to ^10 or 11, but I have gotten some nice
carbon trapping.
Body reduction starting @ ^012 to 010 for at least 30 minutes. I
usually toss some small pieces of wood into the burner ports at this
time. You should see some back pressure. No need to overdo it,
though. Continue with mild reduction up to ^6, then reduce again for
about 30 minutes. I crash cool to orange heat, then turn the burners
back on low for about 30 minutes of slow cooling. I will throw wood in
again at this point. Close the damper and burner ports and allow to
cool as usual.=20
I often take this glaze a little bit higher than ^6. Seems to to be a
little richer looking. As it says below, use a claybody with iron for
best results.=20
This glaze is pretty stiff, as most shinos are. It will stay where you
put it, so every drip will be apparent. White/gray/black where thicker,
orange where thin. =20
=20
>From the Clayart Glaze Database: =20
http://art.sdsu.edu:591/FMPro?-db=3Dclayart%5fdata&-format=3Dclayartrecip=
e.html&-lay=3Drecipe&-op=3Dcn&Glaze%20Name=3Dshino&-op=3Dcn&cone=3D6&-rec=
id=3D33433&-find=3D
Glaze Name: Shino
cone: 6
color:
surface:
firing:Untested
date: 3/26/96
recipe:=20
40.00 Nepheline Syenite
40.00 Spodumene
10.00 EPK
10.00 Soda Ash
100.00 % Totals:
comments:
From the ClayArt Glaze Recipe Database at SDSU.
If you test this glaze and find it useful=20
please consider resubmitting it to the GlazeBase database.=20
estimated thermal expansion: 96.28x10-7/=B0C
Unity Formula for Shino:
0.094 K2O 0.850 Al2O3 3.406 SiO2=20
0.590 Na2O 0.023 Fe2O3 4.0:1 Si:Al Ratio
0.019 CaO=20
0.004 MgO=20
0.293 Li2O
Percentage Analysis for Shino:
58.41 % SiO2
24.72 % Al2O3
2.54 % K2O
10.45 % Na2O
0.31 % CaO
0.06 % MgO
2.51 % Li2O
1.06 % Fe2O3
Possible Health Hazards: Soda Ash: caustic-avoid contact with skin or
eyes or inhalation of mists For 2 years I struggled with this concept
& finally gave up. The fuel savings (?) were not worth the effort. The
results don't compare to ^10. I agree with Peter Pinnell- sell another
mug to pay for the difference in firing costs. Due to the lower
sintering point of ^6 glazes- you have to start reduction fairly early-
at least by stoneware standards. Try ^010 as a starting point & go from
there. I also used a clay body that had a higher iron content than my
present ^10 body- it seemed to make a difference. =20
submitted by: Tom Gray e-mail: tgraypots@atomic.net=20
Hore this helps,
Lori L
lleary@sccoast.net
in Pawleys Island, SC
with a code id by doze.....
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