Mary Adams on wed 12 apr 06
Hi clayart folks,
I've been working on understanding glaze-making for some time now and have
generally bounced back from challenges because I could understand what was
going on and fix it (or toss out a batch and start over). This time I've
been stumped by four recipes (from different sources) going to heavy
pudding. I was meticulous (as I always am cause I tend to be "anal" about
these things) not only in measuring; but, in the method and labelling.
Since I had this happen a prior time, I started investigating with the
author of a couple of them and found out from two different sources that I
probably don't need to add bentonite when there is a certain percentage of
clay in the recipe. I was instructed to wash the recipe (let the water rise
to top, siphon it off and re-add distilled water). Still pudding.
So, this go-around in making these four recipes, I didn't add bentonite and
used distilled water. Pudding anyway. So, now I need to look at the fact
that these four recipes are all going to heavy pudding. The consistent
ingredients in each recipe is EPK and Custer Feldspar (otherwise the Frits
are different and additives different) I'm guessing it's not needing
flocculation because they are all suspended in the mix and not sinking like
cement on the bottom. Over-flocculated? I've now tried sodium silicate (a
few drops mixed in and let it sit). It seems to be thinning. I've used it
on a test piece and we'll see....
I guess my bottom line question to you folks is: do I give up and just buy
off-the-shelf glazes and add colorants and GIVE UP. I can be the most
meticulous person in the world; but, if the water affects it, the chance
that something is mislabeled (either by me or the store???) -- so many
variables. What are the choices you have made and why??? I invite any
recommendations and will not consider anything "misinformation". This is
hard and frustrating
Sidebar: In writing about glaze mixing in the past I mistakenly used the
word "misinformation" with regard to someone telling me it's probably
appropriate to always add bentonite (1-2%). "Misinformation" was too strong
of a word. It was the best shot for the situation at the time. And, that
person was willing to help me and by using the word "misinformation" I
labeled it negatively. Sorry.......
..............Thanks, Mary
Elizabeth Priddy on wed 12 apr 06
I like to buy them because I found a company that
makes glaze that had all the properties that are
important to me and that has been consistent and high
quality for over 20 years now.
I first used them because of OSHA regs in children's
clay classes and used their low fire line. Then I
tried their high fire line and liked it very much and
began using it in my studio. It fit my locally
purchased bag clay perfectly, a luck thing that I
capitalized on. You will have to do some testing to
find your true bought glaze love.
Until I had need for something else and I could still
accomplish all I wanted to, I used these exclusively
for one main reason, that they were designed to work
together.
So I would say that if you want to use comercial
glazes, find one source and use the ones that are
designed to work together in the first place instead
of trying to mix and match chemistry. You can gat a
sample kit from any reputable glaze outfit for between
50-100 dollars. It is worth it, consider how much you
have spent failing to design a line of glazes for
yourself.
I am not ron or jon or diana nor john B. nor Bob
Stryker, who designed the line I use.
The glaze I buy does not crawl, spit, pit, or move in
bad ways. I have never wasted a dime on chemicals and
every batch of glaze I have used for the last 20 years
was tested by a chemist for formulaic precision and
quality before I touched it. This is worth the loss
of control for me, and I would say that the control
you were trying to achieve is not happening for you.
I learned how glazes work, mixed glazes for a potter
friend, know how to do line blends and understand
chemical safety, storage, and use. And I made the
executive decision to leave glazemaking for the last
part of my life and career. It is still on hold and
will probably be quite absorbing when I get around to
it, but it will have to wait, as I have things to do
that interest me more and that fit my skill set
better.
I used to be ashamed but now I am proud. Do what you
do best and focus on that and you can be great.
Piddle with everything others tell you you have to and
you might, maybe if you are lucky, become a jack of
all trades and a master of none.
I am a master level chinese brush painter and teacher.
I am adequte at making glaze. I prefer to do the one
I really love and shine doing.
Follow your bliss and pay a chemist for things you
either are not interested in or are not good at.
But give something a real try before you give up on
it. I think you are there.
It is like the sexual advice I gave a young friend
when it became age appropriate and relevant because
they asked. Try everything at least twice unless you
can get killed doing it. You don't know the color of
your freak flag until you see it. And the first time
doing anything is weird, possibly gross and might be
freaking you out just a little too much to enjoy it.
But then give it a thought and do it again. All those
distractions will not be in play and you can decide
with an informed opinion whether you want to pursue it
as a hobby or vocation or if it might just be
something you leave in Vegas, but which will make your
smile very musterious when you are old. Otherwise,
you just might miss out on the thing that REALLY flips
your triggers due to prudery or bias or bigotry, and
that would be sad.
Also better advice for the young, who are more
flexible in spirit and in the flesh. Don't take this
advice if you are entrenched with 4 kids in a 20 year
marriage and feeling restless unless your sig other is
on board and in the same room with you or divorce may
occur. You have been warned.
Surprising the tips you might run across when you read
long post to the end, isn't it?
Take it easy and be kind to yourself. Do what you
like after trying it often enough to really know. And
trust your instincts, no one has to be there living
your life 24/7 except you, so do what YOU like to do
or you will just be stressed out and miserable, "real"
potter or not.
And learn to dance, it frees the soul.
All the advice fit to print today, so I am going to
stop now.
E
Tony thinks he can shock me with sexual innuendo and
the like but he has no idea just what I may have left
in Vegas in younger wilder days. Sometimes old ladies
can surprise you, they just choose not to.
Elizabeth Priddy
Beaufort, NC - USA
http://www.elizabethpriddy.com
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Daniel Semler on wed 12 apr 06
Hi Mary,
Certainly. Don't give up. What you learn from such hurdles will just help you
later.
Custer and EPK are not going to pudding (the verb "to pudding" - Silicon
Valley has destroyed English - oh well - or is that re-released it as V2.0 ?)
on their own that I know of.
It would be useful to know the full recipes to see if there is anything
suspicious or not. That said, if you don't want to publish them to the list
feel free to throw them at me directly and I'll see if anything jumps
out. But,
it is possible its simply an error somewhere as you say.
Oh BTW how much water are you adding ?
Thanx
D
Chris Schafale Clayart on wed 12 apr 06
Hi Mary,
When I first started making glazes, I went through something very
similar. Glazes that worked great for other people all turned into
pudding, which, applied to pots, cracked, fell off, or crawled in the
firing. I consulted with Ron, Clayart as a whole, and every book I could
get my hands on. I tried additives. I tried washing the glaze. I tried
applying the glaze thinner. I tried distilled water. Nothing worked.
In the end, I did several things which seemed to help get the problem under
control and allowed me to go on mixing glazes. Here they are, for what
they are worth. There are certainly people who will tell you that they do
otherwise and get fine results. All I can say is, this is what works for me:
1) Never use more than 15% raw clay in a glaze recipe.
If the recipe calls for more than that, I use calcined clay to make up the
difference. I just keep a bucket of calcined EPK in my glaze kitchen for
this purpose. When subbing calcined for raw clay, you don't need to use as
much because of the water-weight that is lost in calcining. Multiply the
recipe amount by .87, so for every 100 grams of raw clay, you use 87 grams
of calcined. (To calcine clay, take a big bisqued bowl, fill it with raw
clay, and stick it in your next bisque firing.)
2) Use something other than EPK for the raw clay component.
I got hold of a bag of Pioneer kaolin and used that for awhile, and lately
I've been using a ball clay called Number 1 Glaze Clay. If you use glaze
calc software, it's easy enough to adjust your recipe to accommodate a
different clay.
That's it. I also started bisquing my pots to a lower temperature, which
helped with the crawling, but that's not related to the pudding problem. I
no longer use distilled water, and the problem has not recurred (knock
wood). I don't use bentonite, nor do I use CMC or other additives.
I still have a huge bucket of "pudding blue" that I couldn't bear to throw
out because it's loaded with cobalt. Every so often, I stir it up and try
it on a pot. It's still goopy, and it still cracks when it dries. I've
been able to use some of it up by mixing half and half with a base glaze
made with all calcined kaolin, so maybe by the time I retire it'll be gone.
Good luck. As Elizabeth says, there is no shame in using commercial
glazes if that's what you decide to do. Especially now, when there are a
lot more choices than even a few years ago. But if you really want to make
your own, don't give up.
Chris
At 10:51 AM 04/12/2006, you wrote:
>Hi clayart folks,
>
>I've been working on understanding glaze-making for some time now and have
>generally bounced back from challenges because I could understand what was
>going on and fix it (or toss out a batch and start over). This time I've
>been stumped by four recipes (from different sources) going to heavy
>pudding. I was meticulous (as I always am cause I tend to be "anal" about
>these things) not only in measuring; but, in the method and labelling.
>Since I had this happen a prior time, I started investigating with the
>author of a couple of them and found out from two different sources that I
>probably don't need to add bentonite when there is a certain percentage of
>clay in the recipe. I was instructed to wash the recipe (let the water rise
>to top, siphon it off and re-add distilled water). Still pudding.
>
> So, this go-around in making these four recipes, I didn't add bentonite and
>used distilled water. Pudding anyway. So, now I need to look at the fact
>that these four recipes are all going to heavy pudding. The consistent
>ingredients in each recipe is EPK and Custer Feldspar (otherwise the Frits
>are different and additives different) I'm guessing it's not needing
>flocculation because they are all suspended in the mix and not sinking like
>cement on the bottom. Over-flocculated? I've now tried sodium silicate (a
>few drops mixed in and let it sit). It seems to be thinning. I've used it
>on a test piece and we'll see....
>
>I guess my bottom line question to you folks is: do I give up and just buy
>off-the-shelf glazes and add colorants and GIVE UP. I can be the most
>meticulous person in the world; but, if the water affects it, the chance
>that something is mislabeled (either by me or the store???) -- so many
>variables. What are the choices you have made and why??? I invite any
>recommendations and will not consider anything "misinformation". This is
>hard and frustrating
>
>Sidebar: In writing about glaze mixing in the past I mistakenly used the
>word "misinformation" with regard to someone telling me it's probably
>appropriate to always add bentonite (1-2%). "Misinformation" was too strong
>of a word. It was the best shot for the situation at the time. And, that
>person was willing to help me and by using the word "misinformation" I
>labeled it negatively. Sorry.......
>..............Thanks, Mary
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
Light One Candle Pottery
Fuquay-Varina, North Carolina, USA (near Raleigh)
www.lightonecandle.com
Galleries of Pottery Forms by Clayart Potters: www.potteryforms.org
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Elizabeth Priddy on wed 12 apr 06
If i was trying to de-pudding a glaze, i would
cut it with CMC which I use to "harden" a base
that I like to paint on to.
It is organic and burns out, but it seems to
stiffen up soft surfaces.
Try a quarter cup of your pudding and a 1/4 teaspoon
of CMC up to about a teaspoon.
I don't hink it could hurt it, but I am not a glaze
guru, so I might run it by someone else.
E
Elizabeth Priddy
Beaufort, NC - USA
http://www.elizabethpriddy.com
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Bonnie Staffel on thu 13 apr 06
Thought I would add my two cents worth here abut CMC. If you are adding =
CMC
to your glaze if it is already wet, I would mix a little bit in boiling
water which will make it into a gel quite quickly as your stir. Then =
use it
carefully by adding very little at a time as it will suspend the glaze
particles as well as making a hard surface on which to paint. My ratio =
is
1/4th of 1% dry CMC to the total of the glaze formulation, just to give =
you
an idea of how little you need. Mine doesn't mold or spoil so there may =
be
two kinds of CMC. Ceramic grade may be the correct designation. There =
is
also CMC used in food and medicine, so it may have a different base.
Bonnie Staffel
http://webpages.charter.net/bstaffel/
DVD Throwing with Coils and Slabs
DVD Beginning Processes
Charter Member Potters Council
Judi Buchanan on thu 13 apr 06
To all who feel apologetic about buying glazes,
A painter isn't criticized because he doesn't weave his canvas or mix his
paints from the raw earth materials. He is simply judged by the art he
creates. Many potters still have a lot of 1960's hippy attitudes about
rejecting modern technology and respecting most the pots made by the most
primitive techniques. Hogwash! Just learn to make good pots. Use the
techniques and technology you are comfortable with.
Now this is written by glaze addict, who seldom fires the kiln with out a
test or ten in it but that is my thing.
The amount of knowledge in this field is so broad and so deep it takes
years to master small areas of it, and isn't that what we old timers enjoy
about it? After 30+ years the best pot is still just ahead.
Judi Buchanan,Flutter-by Pottery, south Mississippi
Lynn Goodman Porcelain Pottery on thu 13 apr 06
I use lots of CMC, so I'm adding on to this note:
For dipping/pouring glazes, I use 1/4 of 1%, like Bonnie. For painting,
I use 2%. (Both a percentage of the dry weight.)
As far as the stinkyness factor, some stains, for whatever reason,
promote the growth of nasties. (The encapsulated stains seem to be the
worst; I don't have problems when I'm using oxides instead.) I put
clorox into everything. In addition, if a glaze has gone stinky, I will
use it up (the growth is unpleasant, but won't affect the glaze), but
throw out the container once the glaze is finished, so I don't
contaminate the next batch.
The CMC we get from the ceramic supply places are a different grade
than what is used for food, but it is still a very safe, non-toxic
product.
Lynn
On Apr 13, 2006, at 2:37 PM, Bonnie Staffel wrote:
> Thought I would add my two cents worth here abut CMC. If you are
> adding CMC
> to your glaze if it is already wet, I would mix a little bit in boiling
> water which will make it into a gel quite quickly as your stir. Then
> use it
> carefully by adding very little at a time as it will suspend the glaze
> particles as well as making a hard surface on which to paint. My
> ratio is
> 1/4th of 1% dry CMC to the total of the glaze formulation, just to
> give you
> an idea of how little you need. Mine doesn't mold or spoil so there
> may be
> two kinds of CMC. Ceramic grade may be the correct designation.
> There is
> also CMC used in food and medicine, so it may have a different base.
>
> Bonnie Staffel
>
> http://webpages.charter.net/bstaffel/
> DVD Throwing with Coils and Slabs
> DVD Beginning Processes
> Charter Member Potters Council
>
> _______________________________________________________________________
> _______
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
>
Lynn Goodman
Fine Porcelain Pottery
548 Court St.
Brooklyn, NY 11231
718-858-6920
Cell 347-526-9805
www.lynngoodmanporcelain.com
steve graber on fri 14 apr 06
judi - thanks to hear this. to me - in serious hobby mode these years - my analogy is like a sailor with a nice boat and full set up, somehow being still perceived as less of a sailor then one who lives aboard their boat. even after decades of sailing.
i don't have the time to spend prepping all the materials, and buy what i can where i can. somewhere in the future, retirement i suspect, i might finally mix more glazes by hand. but for now i don't mind buying. i see my current job as a sponsor while i explore pots without the urgency of getting sales. i don't see the issue in prices either, where at a $35 bag of glaze it might add $0.15 to the price of a pot. sure mixing batches of glaze might be cheaper, but how many pots can one also make during that same time slot? is that the best time spent?
i see people who mix their own glazes & get the same results i get from buying pre-mix glazes from aardvark... ~ my supplier being no sloppy supplier as well!
see ya
steve
Judi Buchanan wrote:
To all who feel apologetic about buying glazes,
A painter isn't criticized because he doesn't weave his canvas or mix his
paints from the raw earth materials. He is simply judged by the art he
creates. Many potters still have a lot of 1960's hippy attitudes about
rejecting modern technology and respecting most the pots made by the most
primitive techniques. Hogwash! Just learn to make good pots. Use the
techniques and technology you are comfortable with.
Now this is written by glaze addict, who seldom fires the kiln with out a
test or ten in it but that is my thing.
The amount of knowledge in this field is so broad and so deep it takes
years to master small areas of it, and isn't that what we old timers enjoy
about it? After 30+ years the best pot is still just ahead.
Judi Buchanan,Flutter-by Pottery, south Mississippi
______________________________________________________________________________
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
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