Linda Arbuckle on fri 28 feb 97
>----------------------------Original message----------------------------
>>Terra sig is usually applied to the unfired piece, bisques *no higher*
>than ^012 and if refired, then ^010 maximum. Take a look at the current
>issue of CM and note that the clay itself makes a perfect terra sig.
>No need to mix, deflocculate, decant, etc. As long as your clay is
>without heavy grog, you can actually create the terra sig on the surface
>of the pot.
----------------------------
In response, I fire sig to 03 regularly. Yes, many sources say that if you
fire sig above lowfire temperatures the waxy surface disappears, but I find
if I make a good sig, it works fine. I have a nice Bill Brouillard pot
fired in cone 6 opxidation with a sig rim that is very glossy for sig, very
dense. I was amazed.
Sig works because you decant the very finest clay particles. Those fine clay
particles sitting next to each other give sig it's characteristic surface.
Sigs are often buffed to a higher sheen. I do not find that clay iteself
makes a perfect sig. Burnishing a clay surface will also give a waxy look,
but from you pressing the particles into a plane, but is not exactly the
same as a sig. It helps to deflocculate so that the particles don't clump
and settle, but remain separated, so the heavy ones settle and the light
ones stay in suspension to be siphoned off for sig. If you want the whole
explanation about deflocculation, read the article in Frank Hamer's "A
Potter's Dictionary".
Linda
Linda Arbuckle
Associate Professor, Graduate Coordinator
University of Florida, Box 115801, Gainesville, FL 32611-5801
e-mail: Linda Arbuckle@ufl.edu
Vince Pitelka on sat 1 mar 97
>>Terra sig is usually applied to the unfired piece, bisques *no higher*
>than ^012 and if refired, then ^010 maximum. Take a look at the current
>issue of CM and note that the clay itself makes a perfect terra sig.
>No need to mix, deflocculate, decant, etc. As long as your clay is
>without heavy grog, you can actually create the terra sig on the surface
>of the pot.
This is completely misleading. If you do as directed above, you do not have
a terra sig. If you really want terra sig results, they you have to make
proper terra sig. I have been something of an advocate for a rather complex
approach to preparing terra sig. It works for me, and I am convinced that
it is absolutely worthwhile. But there are many potters out there with
other approaches to preparing terra sig which yield good results. In
common, they all involve settlling and decanting, and most involve
deflocculants. Without those parts of the process you do not end up with
true terra sig.
And again, regarding firing temperature, if you are burnishing the surface
of your wares, you cannot fire higher than ^012, but if you are just buffing
terra sig, you can fire into the upper limits of the low-fire range. I have
not worked with sigs in the mid or high-fire range, but others have. Linda
Arbuckle's post today reports high-fire sigs still showing a high sheen.
Darrol Schillingburg, in Elephant Butte, NM is getting beautiful satin
finishes reduction firing buffed sigs to ^6. Louis Katz reports to me that
a goldart sig gives a nice satin sheen at ^10.
To get the true terra sig gloss which is so famous, I do not believe that
you can fire any higher than the upper limits of low-fire temperatures.
- Vince
Vince Pitelka - vpitelka@DeKalb.net
Phone - home 615/597-5376, work 615/597-6801
Appalachian Center for Crafts
1560 Craft Center Drive, Smithville TN 37166
Peggy Heer on sat 1 mar 97
Hi everyone...I agree with Linda...I always fire my terra sigs at ^07 for
the first fire. I have in the past done 'pit fire' in my gas kiln and have
got good results at ^07 with the second, smoking fire as well. I have also
fired Terra sigs to ^8 and retained the sheen. It all depends on what clay
you are using to make the sigs. Robin Hopper has fired terra sigs to ^10
with good results. These are not smoked but have a nice sheen to them
anyway. I fired some left over ts'd porcelain work in my last ^10 reduction
fire and the sheen is still there. They will not take on any smoke like
the lower fired work because the clay is now sealed, but an experiment is
an experiment and new work always comes from people who are willing to
experiment. Like Robin Hopper, as well as many others say, 'Try it and
see". ;>}}}
There are no hard and fast rules. Experiment.
As Always in Clay Peggy
------------------------------------------
snip....
>>>Terra sig is usually applied to the unfired piece, bisques *no higher*
>>than ^012 and if refired, then ^010 maximum.
>----------------------------
snip
>In response, I fire sig to 03 regularly. Yes, many sources say that if you
>fire sig above lowfire temperatures the waxy surface disappears, but I find
>if I make a good sig, it works fine.
Peggy Heer / Heer Pottery E-Mail p4337@connect.ab.ca
Edmonton AB, Canada
http://www.ffa.ucalgary.ca/artists/pheer/
Ron Roy on mon 3 mar 97
>----------------------------Original message----------------------------
>
>>----------------------------Original message----------------------------
>>>Terra sig is usually applied to the unfired piece, bisques *no higher*
>>than ^012 and if refired, then ^010 maximum. Take a look at the current
>>issue of CM and note that the clay itself makes a perfect terra sig.
>>No need to mix, deflocculate, decant, etc. As long as your clay is
>>without heavy grog, you can actually create the terra sig on the surface
>>of the pot.
>----------------------------
Laurence clearly states Terra sig can be fired to cone 10 - it depends on
the clay you use. I use a variation of my own composition at C10r on my
snow plates. You can see an example in Contact magazine, spring 95.
Ron Roy
Toronto, Canada
Evenings, call 416 439 2621
Fax, 416 438 7849
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