bill edwards on fri 30 sep 05
This is just a summary on the many glazes I have
visited, seen, explored and often written. It is still
amusing to see a glaze in a book, then see the author
of that glaze show it in another light, another place
at another time and the glaze take on a totally
different look, sometimes it just doesn't look the
same does it? This facinates me still because the end
is nowhere in sight due to clay bodies, firing
differences and often minor chemical variations within
one of more compounds that make up a glaze.
I wake up with a new journey in mind every morning. I
often take my 2.5 mile speed walk in the morning at
Horseshoe Bend National Park to help me with my health
problems and my mind is thinking about the people
here, the glazes, all 100's of thousands of them and I
try to put them into some kind of category, and I
fail, often!
The better part of me comes back, sweaty and tired but
ready for the studio and a new challenge. Can I
complete my mission before I pass on, I ponder? Can I
get what I am looking for the next time I fire? Should
I return to reduction firing or....The good and bad of
thought processes take over. The good wakes up and
tells me I have just started this exploration, the bad
says I have seen enough and yawns and insists I go
back to bed.
Browns and Reds from Iron - I stick with iron in alot
of what I do. I used iron, rutile and a good deal of
tin. I see more often than not where someone is
reaching for the ketchup reds and gets a brown, like
many of us who author books or do glaze calculations
and has pyromania-virus, a retro glaze virus thats
highly catching or contagious. We were given the ax on
using Gertsley Borate, which often was the backbone
for these glazes so what can we do? Primarily we need
to depend on the heat in bringing out the reds and
often these RIO glazes are high in Fe low in Al203.
Drop the heat from your ^6, to 1650F and drop on down
to 1550 taking about 1.5 hr's to lose the 100 degree
drop and then cool. This is the area I have worked to
get the brighter reds, others I am sure have a
different solution. Bear in mind, high Fe, low Al203.
Often these go beyond the Al:Si ratio I would use for
durable wares and range out of other areas as well but
RIO in high ammounts added as part of the base makes a
difference. The same glaze with copper may very well
give you a new kiln or in the least lots of cleaning
of shelves.
Cobalts - I use so little of it but I do so much with
it. Back off magnesium and manganese unless your
looking for something outside of deep clean cobalts.
You may find a wild gray or purple thats not up to
snuff. My old Water Faux Blue finds its iron content
from other sources. Some have asked me if I added iron
after viewing the blog where I had some pictures. No,
but there is iron which is pulled from other sources
within the glaze matrix and layers on sharp areas and
raised points and often looks like it was heat kissed
in a wood kiln.
Copper - Another one I don't use often. I have a
turquoise blue glaze I developed and then accidently
threw the information away after changing my
calculations software around. Life happens, it will
happen again and I am experimenting to get this jewel
back. I noticed that it does better after it stands
for a month of so. Solubles and such. Often this could
go the reverse.
Chromium - I use it often and I use it in small
amounts. The lab tests I usually do where chromium is
involved is usually done at 4% levels, enough to gag a
person on green. I never use zircon, ultrox or other
tin replacements even though I have some of them in
stock. What I stated some time back about having tin
in a kiln with chrome can work if you know more about
whats going on in the fire. It never bothers me that
no one listens and they go on to ask the same thing
over and over to others thinking they have better mojo
or magic. I say go where your heart and soul sends
you. It only can make you better.
Tin - I stock up on this and usually buy in bulk. Tin
is the best opacifier I have used that comes out a
true white. If I am using wollastonite and tin I will
often homogonize these two to prevent any specking.
You can do this as well by mixing any larger particle
material with a small ammount of your base water and
using one of those hand held blenders, and show these
materials who the real boss is. I use the same for
homoginizing CMC in room temperature water where
others insist it must be hot only. Hot works if you
are in a rush to get there. CMC, and I have virtually
used a ton of it in the past, it will break down under
shear force but thats not the topic here. Hot water
and some CMC in a pint jar with some good shakes
works. This is just FYI in case someone missed the
last pro's and con's on this subject.
Rutile and Ilmentite - Stock up on it. These vary too
much like RIO. Buy from a reputable supplier, ask
questions and get literature such as % analysis of the
core ingredients. Iron can be anywhere from 50% to
99%. SRIO varies, there no absolute method on
determining this unless you have their lab report in
front of you. There is standardized sythetic versions
of iron now.
I wanted to write this because I have been getting a
good bit of mail asking me what I usually use. I have
Blue Mtn Neph Syen, Ferro G-200, Redart, 3134, 3124,
GB old stock and used only for testing and washes,
NC-4, Silica, OM-4 Ball, EPK, Calcium Carb,
Wollastonite, Talc, Bentonite, RIO, Ilmenite and more
that I am forgetting. I buy these in 100 pounds and 50
pound bags. I buy my colorant oxides mostly in 5
pounds but tin is usually bought in 10 pounds+. I
always get a test sample of their stock and ask they
hold any large purchases needs I have from that very
stock till I can test it and if they can't, I move to
the next supplier unless they will give me the purity
analysis and I will eat any problems if they do that.
Larger companies understand this and will often work
with you. Some refuse, fine, I can refuse as well and
I do!
manganese Dioxide - Of course I use this. I don't eat
it or breath the fumes. I know where I want it to go
and not to go. You will see it has and always will be
used by even the best potters and often is found in
the best written books on the market. We just need to
use it wisely like we would other materials that can
compromise our health. Right now its added to the
fuels we use and I am sure compounding more costs to
the already high price of driving over 80. Back when
the speed limit was set lower, I bet there was a major
difference in consumption of fuels.
Zinc - I have some, I don't like zinc and I have
strayed from macro-crystal glazes years ago. If you
buy it, calcine it or buy it calcined. The last zinc I
used was put on a jug that I thrown, altered, carved
and cried over. It was very pretty! I didn't want to
do it again. It was enough to last me a life-time!
I will BLOG my latest 3 or 4 glazes soon. Pictures
only. And I am once again on the prowl for a trade.
Teabowl for teabowl or toad, it doesn't mattter and I
make no judgement calls. I respond by delight, not
critique unless there's a very observed need or I am
asked. My collection isn't a George Ohr but I am just
as proud of it and the potters that used their hands
to produce these pieces that grace me every morning
with a nice, in tune 'welcome back to the studio.'
Yes, my pots sing to me and it's like having a room
full of friends when I set down at the wheel once I
pass the gallery and move into my work mode and
harness myself into my chair for the lift-off and
landing of a new pot.
The next time I do a trade, and if someone wants, I
will be most happy to dry mix my Clear Gloss for them
and send it along for a 500 gram test run. I did take
it down from the BLOG but it's available to those who
enjoy the archives. I would like to track your
progress upon your using it and know the clay body if
possible. I even had it lab analized for boron content
and with multiple colorants. Now that information
comes with the book, just a simple intuitive study
(lab reports) on glazes both functional and
decorative. Intuitive can be mis-leading. It's a
matter of practical application and exploring beyond
the boundries known as limits we are given. These
limits are important so don't make any assumptions,
you will lose the ball-game. But there's small areas
of wiggle room that lives outside the parameters of
standards used that can be explored under the right
circumstances. I think Eduoard recently pointed that
out in his recent BLOG analysis and COE graphs using a
standard against rules of application. I have seen
other notable glaze professionals also roam a little
in that area, sorta fun but calculated risk and
assessments need to be given great consideration or
risk problems losing pottery, kiln shelves etc. We
don't want anyone getting sick either but I still
haven't found anything scientific proving that any of
the conventional materials we currently use have done
this from leaching or crazing with few exceptions. I
do know of potters being poisoned by fumes and
handling raw materials. And I confess, we don't need
to add to the glazes we use for functional products
known to be used for food service where any
potentially bad material could be leached but often I
am not thinking or talking 'just about' dinnerware
when I write. Really, I want go there right now
because its just confusing and I support good glaze
techniques and chemistry but we can't possibly have
all the facts perfected, the vastness of all this is
just now beginning to be un-covered inparticular to ^6
oxidation. It's just not worth it and your name is
often on the bottom of those pots for the World to see
anyways. Keep a good name and use the right glaze for
the right surface and track the progress. I could go
on a little more but I feel I have lost 90% of my
viewing audience by now. But thanks for trying to get
this far anyways. Make sure you always sign your name
good and clear so everyone can see it. I see too many
piece on the market and you can't tell if a rat ran
across the bottom of someone slide a rock under it
when lifting it off the bat. Those signatures are
worth something to someone. Leave your potters-mark,
no need in spending all that time producing great
pieces and toss it off with poor signing or feather
dusting script. People will look for you if they have
something to go by and you get a few things out there
for discerning eyes to see.
Bill Edwards
Edmar Studio and Gallery
302 South Main St (Shipping)
POB 367 (Mailing)
Camp Hill, Al. 36850
http://apottersmark.blogspot.com/
"Those that matter don't mind, and those that mind don't matter"
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