Emily P. Henderson on sat 18 jan 97
Hi all...it's raining, again, so I'm not pitfiring, again. But I've heard
tell of this stuff you put on pots to make them pretty and shine when you
can't burnish and pitfire. I know NOTHING about this stuff so I'm
askin...don't laugh!
Ok, I've got 2 different floating blue recipes that I'd like to try This is
the first:
Neph Sy 45.48
Ghastley B 25.96
Silica 19.52
Milled rutile 3.85
RIO 1.92
Cobalt oxide .96
This is the second: Chappell
Neph Sy 47.3
Ghastley B 27.0
Silica 20.3
EPK 5.4
RIO 2.0
Cobalt Oxide 1.0
Rutile 4.0
CMC 1.0
My confusion.... in the first recipe, the rutile seems to be treated as a
base glaze element and part of the total 100%; in the second, it seems to be
treated as a colorant, (ie., if it were viewed as a glaze component, it
would add up to 104%
From what I've been able to gather, 100% is good, but I often find
statements that baffle me like "If you want to go from ^10 to ^6, substitute
neph Sy for the feldspar and add 10% colmanite" Or, "To drop one cone add
5% colemanite" These confuse me because I don't know what to subtract from
where to get 100% when I start making additions (or subtractions) Is the
100% idea really that important or is it just the ideal? How much can you
fudge?
With the above floating blue glaze, I would like to fire closer to ^7 than
^6 for the sake of my claybody. Can you glaze gurus tell me which of the two
formulae would be most likely to handle that well? And, since I'm sure the
rutile is going to want to make it run, is there a modification (I've read
about something called ilmenite) that will increase the EFFECT of the rutile
to develop crystals but allow me to decrease it's amount?. I've heard these
glazes RUN esph. at the high end of their firing range. TIA Emily in
Astoria, where it's wet, again.....
Roeder on mon 20 jan 97
Emily,
This first one you've listed is from the Clayart Glaze database, isn't it?
I think you left out **EPK 5.19**
Although my name is listed on that first version in the database, I've never
used it. Isn't that goofy? I use the Chappell version. I really don't
know where version #1 came from (I can't find it anywhere in my notes), and
don't know if it works. (Rutile figured into the 100 total? strange..)
When you start adjusting the recipe for cone 7, you might want to use
version #2. I use the second version with 2 percent cobalt carbonate
instead of the 1% cobalt oxide. I fire to cone 6 just beginning to bend.
It will fire to cone 7 also, but the green is more pronounced, which I find
unattractive.
Candice Roeder
>Ok, I've got 2 different floating blue recipes that I'd like to try This is
>the first:
>Neph Sy 45.48
>Ghastley B 25.96
>Silica 19.52
>Milled rutile 3.85
>
>RIO 1.92
>Cobalt oxide .96
>
>This is the second: Chappell
>
>Neph Sy 47.3
>Ghastley B 27.0
>Silica 20.3
>EPK 5.4
>
>RIO 2.0
>Cobalt Oxide 1.0
>Rutile 4.0
>CMC 1.0
>
>My confusion.... in the first recipe, the rutile seems to be treated as a
>base glaze element and part of the total 100%; in the second, it seems to be
>treated as a colorant, (ie., if it were viewed as a glaze component, it
>would add up to 104%
>
>From what I've been able to gather, 100% is good, but I often find
>statements that baffle me like "If you want to go from ^10 to ^6, substitute
>neph Sy for the feldspar and add 10% colmanite" Or, "To drop one cone add
>5% colemanite" These confuse me because I don't know what to subtract from
>where to get 100% when I start making additions (or subtractions) Is the
>100% idea really that important or is it just the ideal? How much can you
>fudge?
>
>With the above floating blue glaze, I would like to fire closer to ^7 than
>^6 for the sake of my claybody. Can you glaze gurus tell me which of the two
>formulae would be most likely to handle that well? And, since I'm sure the
>rutile is going to want to make it run, is there a modification (I've read
>about something called ilmenite) that will increase the EFFECT of the rutile
>to develop crystals but allow me to decrease it's amount?. I've heard these
>glazes RUN esph. at the high end of their firing range. TIA Emily in
>Astoria, where it's wet, again.....
>
Emily P. Henderson on mon 20 jan 97
At 05:56 PM 1/18/97 EST, I wrote:
>----------------------------Original message----------------------------
>Hi all...it's raining, again, so I'm not pitfiring, again. But I've heard
>tell of this stuff you put on pots to make them pretty and shine when you
>can't burnish and pitfire. I know NOTHING about this stuff so I'm
>askin...don't laugh!
>
>Ok, I've got 2 different floating blue recipes that I'd like to try This is
>the first:
>Neph Sy 45.48
>Ghastley B 25.96
>Silica 19.52
>Milled rutile 3.85
>
>RIO 1.92
>Cobalt oxide .96
>
>This is the second: Chappell
>
>Neph Sy 47.3
>Ghastley B 27.0
>Silica 20.3
>EPK 5.4
>
>RIO 2.0
>Cobalt Oxide 1.0
>Rutile 4.0
>CMC 1.0
>
>My confusion.... in the first recipe, the rutile seems to be treated as a
>base glaze element and part of the total 100%; in the second, it seems to be
>treated as a colorant, (ie., if it were viewed as a glaze component, it
>would add up to 104%
>
>>From what I've been able to gather, 100% is good, but I often find
>statements that baffle me like "If you want to go from ^10 to ^6, substitute
>neph Sy for the feldspar and add 10% colmanite" Or, "To drop one cone add
>5% colemanite" These confuse me because I don't know what to subtract from
>where to get 100% when I start making additions (or subtractions) Is the
>100% idea really that important or is it just the ideal? How much can you
>fudge?
>
>With the above floating blue glaze, I would like to fire closer to ^7 than
>^6 for the sake of my claybody. Can you glaze gurus tell me which of the two
>formulae would be most likely to handle that well? And, since I'm sure the
>rutile is going to want to make it run, is there a modification (I've read
>about something called ilmenite) that will increase the EFFECT of the rutile
>to develop crystals but allow me to decrease it's amount?. I've heard these
>glazes RUN esph. at the high end of their firing range. TIA Emily in
>Astoria, where it's wet, again.....
>
_____________________________________________________________________________-
Happily, Candice Roeder who originally posted both recipes to the Clayart
glaze database informed me that I forgot the 5.19 EPK in the first recipe
and also says that she hasn't tried it, t'aint sure of it and thinks it a
bit screwy. She recommends trying the Chappel (2nd. But here is the
"correct" "incorrect" first formula:
Neph Sy 45.48
Gerstley Borate 25.96
Silica 19.52
EPK 5.19
Milled rutile 3.95
RIO 1.92
Cobalt ox .96
Emily in Astoria OR, where it's STILL RAINING but I went to the Portland Art
Museum today to see the Andrew Wyeth "Helga" studies....Who cares if it's
raining? :-)
Pelly123@aol.com on thu 23 jan 97
I fired a test of your second recipe last weekend at cone 6 ox. on porcelain.
It's a beautiful glaze. It was very stable on the pot, did not run, but it
has a hard time with drips...has to be put on absolutely smooth which is a
real problem for me..I need a lot more forgiveness.
Pelly in Rochester, NY..
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