Jim V Brooks on tue 6 aug 02
Gordon, i had the same experience that you have had with Randy's Red. Even
when i fired it with other red iron oxide glazes that came out a beautiful
iron red color--Randys was a mudy brown.. Never could get it to work..so
just gave up.. There are a lot of iron red glazes that do work... so you do
have some choices.
Jim in Denton
gordon jones on tue 6 aug 02
i had read a lot of buzzz about randys red on the potters.org site and
finally a saw it posted as a recipe and saved it. while at a show in north
carolina another potter was going on about a new glaze he had tried called
randys red.it was great black breaking to red with golds and browns,i was
hooked so home i went and mixed a batch as per the recipe i had--Veena
Raghavan jan 99,i had not heard anyone ever say what it looked like other
than this guy from n.c. needless to say it looked much different than i had
hoped hence this letter. i opened the kiln to find mud color with no
breaking colors the pieces dipped double were a nice chocolate no breaking
colors,is this how it should be and i had a nasty trick played on me or was
something not correct.
thanks for any help you can give,please try not to laugh out loud.
gordon, earthbound arts
north carolina
_________________________________________________________________
MSN Photos is the easiest way to share and print your photos:
http://photos.msn.com/support/worldwide.aspx
Paul Lewing on wed 7 aug 02
Gordon, there are many oxidation iron red recipes out there, as someone else
has pointed out. However, they are all very similar, and all very tricky.
They tend to have lots of calcium, almost but not quite as much magnesium,
LOTS of iron oxide, and very little alumina. They tend to have a high
SiO2:Al2O3 ratio, say 18:1 or more, so that even though they tend to be
matte, they also tend to be runny.
A lot of the variables that affect most other kinds of glazes seem to affect
these guys even more. They are VERY sensitive to:
1. Thickness. They need to be pretty thick to be red, but they will run if
they're too thick.
2. Firing cycle. They need to be fired slowly and, more importantly,
cooled slowly. The red color is due to excess red iron oxide recrystalizing
on the surface as the glaze cools, and this takes time. Many people feel
they get a better result from refiring to a lower temperature as this gives
more time for this recrystalizing to happen.
3. Brand or form of iron oxide. I once tested Randy's Red and a number of
variations on it with black iron, yellow iron, and 7 different kinds or
brands of red iron. The color was markedly different.
4. Temperature. These glazes tend to have a narrow temperature window for
optimum redness.
5. Clay body. I've only ever tried them on a white clay, but the reddest
examples I've ever seen have all been on a darker clay body.
So, did someone "leave something out" of the recipe. Yes, in the sense that
they didn't detail to you all the conditions in their studio that made their
version of the same recipe come out red. Conversely, you didn't necessarily
do anything "wrong". You just didn't get all the variables working together
to produce red out of the particular combination of ingredients you were
given. And when someone else tells you that there are "better" iron red
recipes than Randy's, what they're really saying is that some other
combination more reliably makes red when applied the way they apply it,
fired the way they fire it and cool it, using the kind of iron (and even the
water) that they have, fired to the temperature they fire to, on their clay
body.
Now, does that make you feel better? I didn't think so.
Paul Lewing, Seattle
Marianne Lombardo on wed 7 aug 02
Hi Gordon;
I tried Randy's Red a couple of times (oxidation) and gave up on it. The
result I had was a totally opaque reddish brown, more brown than red, that
looked more like paint than a glaze. Very dull looking. Perhaps some
people are using it successfully in reduction firings, I really don't know.
It's not really a matter of someone playing a trick. That's the way it goes
with glaze recipes. Sometimes they work, sometimes they don't. More often
they don't, but it's nice when you get lucky. There are too many variables
involved to expect the same results as someone else. Raw materials differ
from supplier to supplier, mixing varies, application varies, firings vary.
Marianne Lombardo
Omemee, Ontario, Canada
mlombardo@nexicom.net
> colors,is this how it should be and i had a nasty trick played on me or
was
> something not correct.
GORMO1@AOL.COM on thu 8 aug 02
The best randy red fire ^6down and ^7 bending soak and cool slow
does well on buff clays. Clays/redart the glaze will come out
brown in color yes ,even if you cut back the rio in the glaze.
jim gorman
Paul Lewing on thu 8 aug 02
on 8/7/02 9:29 PM, Paul Lewing at PJLewing@WORLDNET.ATT.NET wrote:
> A lot of the variables that affect most other kinds of glazes seem to affect
> these guys even more.
Oh, yeah, Gordon, I forgot one other variable that affects these glazes:
Combination of raw materials. You'll find, if you do the Seger formula
thing, that if you make identical Seger formulas for these glazes from
different combinations of ingredients, some combinations will be markedly
redder than others. This is not usually the case with most glazes, but I've
done this and it makes a huge difference.
Just thought I'd add that to confuse and discourage you some more.
By the way, I've probably done 300 glaze tests on oxidation iron reds trying
to get a really red, really reliable glaze. I finally got one that worked
for me most of the time, so I named it after my dog Towy, who had spots that
color. I used it for several years, but it turned out to be too much like
Towy- quirky and unpredictable. Just wouldn't do what I wanted enough of
the time, much like Towy. I eventually gave up on it, and since Towy died,
I haven't even tried to get a better version. But I'm still trying to
invent an iron red based on a different set of oxides. Maybe some day.
Paul Lewing, Seattle
Paul Taylor on thu 8 aug 02
From: Paul Lewing
Conversely, you didn't necessarily
do anything "wrong". You just didn't get all the variables working
together
to produce red out of the particular combination of ingredients you were
given. And when someone else tells you that there are "better" iron red
recipes than Randy's, what they're really saying is that some other
combination more reliably makes red when applied the way they apply it,
fired the way they fire it and cool it, using the kind of iron (and even
the
water) that they have, fired to the temperature they fire to, on their clay
body.
Now, does that make you feel better? I didn't think so.
Paul Lewing, Seattle
Dear all
Not that Paul lewing Needs any endorsements.
But he has given the big secret away.
Industriasl glazes are designed to go on so the glaze is perfect glass
fitting on the pot it is scratch resistant smooth and high shine and all the
materials in it bought into fusion so all pots glazed will form the perfect
matching industrial set.
Art pottery glazes ,the ones that give interesting effects and colors,
are exactly the opposite.
The glazes are dependent on atmosphere and crystallization . The chases
are that any iron Oxide will work in the Randy's red but you will have to a
just the amount with a line blend to get the amount of Fe2 o3 you need and
also the cooling cycle. If you experiment with these variables in an
intelligent way the chances are you will find the optimum red.
Then you can publish the recipe knowing that unless a potter: is using
exactly the same clay, with all materials the same grade, and particle size
(especially the iron oxide), and then fires the glaze to exactly the same
temperature, with the right rate of clime, and rate of cooling, the potter
is not going to get the results you do - only after line blending the iron
and taking rings out of a slow cooling kiln will he get any where near the
best results.
If you want reliability use a stained slip under an industrial clear
glaze - perfect every time but lifeless.
--
Regards from Paul Taylor
http://www.anu.ie/westportpottery
In time the biggest hammer will fail to smash a nut. that is the nature of
'disaster' - but also 'hope'.
| |
|
