Jonathan Kaplan on tue 3 dec 96
Can anyone suggest or steer me in the right direction for some very basic
raku glazes for a new class that I will be offering at Colorado Mountain
College next semester. My syllabus was approved, we have a new Zen raku
kiln from Mile High Ceramics, and I'd like to query the list for a basic
white crackle, a stable copper matte glaze, and perhaps a blue or a green.
A base glaze would be trick and I can put the class to work on the tests.
My appologies if this is repetative.
Thanks in advance. You all know that I will reciprocate when possible.
Jonathan
Jonathan Kaplan
http://www.craftweb.com/org/jkaplan/cdg.shtml
(aka "Scooter)
jonathan@csn.net
Ceramic Design Group Ltd./Production Services Voice:
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WHampton@aol.com on wed 4 dec 96
Jonathan,
I would get Pipenburgs Raku book. It is full of GOOD recipes and your class
will also enjoy the information in it.
Have fun rakuing!
Wendy from Bainbridge Island WA
If you can't get it let me know and I'll send you some recipes from it.
Anita Suderman on thu 5 dec 96
Jonathan Kaplan wrote:
>
> ----------------------------Original message----------------------------
> Can anyone suggest or steer me in the right direction for some very basic
> raku glazes ...... and I'd like to query the list for a basic
> white crackle, a stable copper matte glaze, and perhaps a blue or a green.
Congrats...
Here are the glazes we use at Hawaii Community College. I am not quite
sure of our firing schedule but we take 1 hour to get to 1750 degrees
(we also bisque to that same temp). We reduce at the end. I dunno the
size of the kiln in cu. ft., but it's like the size of a 3/4 fifty
gallon drum.
Yukio's Rainbow Sand
Colemanite 70
Bone ash 20
Neph. Sy. 10
Lithium Carb. 3
Copper Carb. 5
Cobalt Carb. 0.5
Not enough redux(?)= yellow green
just right=sandy rainbows
applied thick=lizard like scales
too thick=falls off when cool, not sharp pieces
Combination of Transparent Peace and Sorta White Raku
(beats me!)
Colemanite 54
Custer Spar 20
Barium Carb. 10
Flint 6
PV Clay 6
Ball Clay 4
We have variable results with this one... Most of the time it's a great
transparent crackle. It looks wonderful over dark clays and any clay
with engobe decoration etc.
But sometimes it has a gnarly texture....overfired? underfired? Will
have to check out maturing temp more closely. We always fire to 1750 and
not by looking at the surface of the glaze, but if the surface looks
suspect when we open it, we shut it quick and Gordon (prof) watches
through a peep hole.
Black Luster
Colemanite 75
Neph. Sy. 25
Copper Ox. 15
Black Iron Ox. 15
Bentonite 3
Gun Metal Charcoal colored to Black with lots of luster, must change it
to get more glassformers(?) see article on raku glazes at IMC site.
Loses luster (faster on my part of the island due to climate(?)).
Turquoise with red Splotches (sorry totals 200)
Colemanite 126
Flint 63
Zinc 57
Ball Clay 45
Whiting 9
Copper Carb. 9
Bentonite (2%)
texture a little orange peely (?), bright turquoise with small orange
red spots
Also, in glazebase tons of 80-20 copper types, A couple of Red Lusters
plus this one(I haven't tested):
Blue Black Purple submitted by Debbie Altschwager
Rake cone 08-06 ox or redux.
Gerstley Borate 50
Neph sy 50
Copper Carb 50 for Tomatoe Red: Copper ox. 20
Rutile 50 and Red Iron ox. 5
comments: apply 1 coat. they fire 1830-1900 deg. surface like 100 grit
sandpaper. Colored from silver blue to silver bronze with flashes of
color that can run the whole spectrum, lots of bright teal and purple
with halos of fuschia and mustard, once in a while red
More Glazes Later, Sam
Lisa on fri 6 dec 96
Anita Suderman wrote:
> Blue Black Purple submitted by Debbie Altschwager
> Rake cone 08-06 ox or redux.
>
> Gerstley Borate 50
> Neph sy 50
>
> Copper Carb 50 for Tomatoe Red: Copper ox. 20
> Rutile 50 and Red Iron ox.
>
> comments: apply 1 coat. they fire 1830-1900 deg. surface like 100 grit
> sandpaper. Colored from silver blue to silver bronze with flashes of
> color that can run the whole spectrum, lots of bright teal and purple
> with halos of fuschia and mustard, once in a while red
>
One thing that was not mentioned re: this glaze is that the parts are
SUPPOSED to be measured by volume, not by weight. I didn't know this the
first time I made a batch, and did my measurements by weight. We dip
pieces to glaze, and when fired, this glaze peeled off the pot and made
very ugly sharp places to boot.
After that experience I found out that the glaze should have been mixed
by volume, and mixed a new batch. Unfortunately, the "correct" batch
isn't nearly as pretty IMHO as the "wrong" batch (Now dubbed the Magical
Mystery Glaze), which works quite well when brushed on thinly instead of
dipping.
Either way you mix it, the glaze colors up better if you put a clear or
white under or over it.
WHampton@aol.com on sat 7 dec 96
In a message dated 96-12-06 05:11:06 EST, you write:
<< One thing that was not mentioned re: this glaze is that the parts are
SUPPOSED to be measured by volume, not by weight. I didn't know this the
first time I made a batch, and did my measurements by weight. We dip
pieces to glaze, and when fired, this glaze peeled off the pot and made
very ugly sharp places to boot.
After that experience I found out that the glaze should have been mixed
by volume, and mixed a new batch. Unfortunately, the "correct" batch
isn't nearly as pretty IMHO as the "wrong" batch (Now dubbed the Magical
Mystery Glaze), which works quite well when brushed on thinly instead of
dipping.
Either way you mix it, the glaze colors up better if you put a clear or
white under or over it. >>
Why would volume vs grams make a difference. As I read the recipe (and I
could easily be way off base) you would use 50g (or 1 cup) of G.B. and 50g
(or 1 cup) or N.S. That would equal 100g or 2 cups. You would then add 25g
(or 1/2 cup) of Copper Carb and 25g (or 1/2 cup) of Rutile.
Am I interpreting this correct??
Thanks
Wendy from Bainbridge Island WA
June Perry on sun 8 dec 96
Dear Debbie:
Could you explain your raku recipe? You mention that for tomato red you add
copper ox 20 and red iron oxide but you didn't give an amount of the red
iron.
Could you please clarify.
> Blue Black Purple submitted by Debbie Altschwager
> Rake cone 08-06 ox or redux.
>
> Gerstley Borate 50
> Neph sy 50
>
> Copper Carb 50 for Tomatoe Red: Copper ox. 20
> Rutile 50 and Red Iron ox.
Thanks!
June
Thanks!
June
ZALT@aol.com on sun 8 dec 96
Wendy;
I didn't see the recipie that you are talking about, but I suggest you
always think weight vs volumn unless specified very clearly in the recipie.
You must remember that glaze material has various densities. This means that
one cup of one product will not necessarly weight the same as one cup of
another. A good example would be to weight one cup of silica then weigh one
cup of colemanite you will see a great difference between the two.
Best Regards
Terrance F. Lazaroff
St Hubert, Quebec, Canada!!!!
Charles Williams on mon 9 dec 96
Jonathan,
Try "RAKU POTTERY" by Robert Piepenburg (Pebble Press< Farmington Hills,
Michigan). This book has numerous RAKU formulas.
Piepenburg White:
70% Gerstley Borate
15% Cornwall Stone
10% Tin Oxide
05% Flint
Silver White Base
5 parts Gerstley Borate
3 parts Nepheline Syenite
2 parts Lithium Carbonate
! You may not want to use this in a classroom setting due to the toxicity of
Lithium Carbonate !
Hope this helps!
C WILYUMS AKA Mississippi Mudcat Pottery
Lili Krakowski on mon 9 dec 96
I am not entirely clear what the problem is. BUT: some years ago I
measured out stuff and then weighed it, as a "rule of thumb" for changing
weighed out glazes to volume ones. I found that with a lot of materials
it made a difference whether I scooped the materials out (measuring cup
dipped into bag, leveled with knife edge as in baking) or filled a larger
container using a spoon to transfer materials from bag to cup. With some
materials the difference was greater with others less. I will see if I
have the list with me and try to put it on e-mail. I also found by the
way that measuring cups are only approximate and that let us say a 1 cup
cup from Manufacturer A is a bit bigger or smaller than from
Manufacturer B. And of course a cup of magnesium carb. will way
tremendously less than a cup of silica. But you knew that. May I
suggest that you get glass containers (jam jars) and put the by-volume
amount needed for each material each in one jam jar. Level by shaking
jar; then place jar on wheel and at eye level draw a permanent line
(marker) at that level. Mark each jar with name of material and it will
all work out quite scientifically. Yes, you can use one jar for several
materials.Good luck
Lili Krakowski lkkrakow@edisto.cofc.edu
On Sat, 7 Dec 1996 WHampton@aol.com wrote:
> ----------------------------Original message----------------------------
> In a message dated 96-12-06 05:11:06 EST, you write:
>
> << One thing that was not mentioned re: this glaze is that the parts are
> SUPPOSED to be measured by volume, not by weight. I didn't know this the
> first time I made a batch, and did my measurements by weight. We dip
> pieces to glaze, and when fired, this glaze peeled off the pot and made
> very ugly sharp places to boot.
>
> After that experience I found out that the glaze should have been mixed
> by volume, and mixed a new batch. Unfortunately, the "correct" batch
> isn't nearly as pretty IMHO as the "wrong" batch (Now dubbed the Magical
> Mystery Glaze), which works quite well when brushed on thinly instead of
> dipping.
>
> Either way you mix it, the glaze colors up better if you put a clear or
> white under or over it. >>
>
>
> Why would volume vs grams make a difference. As I read the recipe (and I
> could easily be way off base) you would use 50g (or 1 cup) of G.B. and 50g
> (or 1 cup) or N.S. That would equal 100g or 2 cups. You would then add 25g
> (or 1/2 cup) of Copper Carb and 25g (or 1/2 cup) of Rutile.
> Am I interpreting this correct??
> Thanks
> Wendy from Bainbridge Island WA
>
LizzardOL@aol.com on wed 11 dec 96
To add to the following discussion about the blue/black purple raku - I too
mixed a batch by weight and tested it on white and dark stoneware. Since it
was a test, I simply poured it on part of the vases and in both cases got a
rather dull, smooth, metallic copper surface. For yuks I painted on a stripe
of slver nitrate and got a rather dull, smooth, metallic tin surface. No
shards but no brilliant flashes either. Vive la difference??? I'll try the
clear and white suggestion and tell you what happens for me.
The Raku rainbow posted earlier here did give brilliant copper sand effects -
grainy, copper metallic with beautiful blues and magentas - thank you whoever
posted that recipe. Many people at the Potters Studio asked for the recipe,
which I shared with them on the theory that being a good example would
engender similar sharing on the part of others. One person went to far as to
tell me that it was outlandish not to share information with other potters;
but the same day refused to tell me the recipe for a turquoise barium glaze
of hers I was admiring ("I have to think about it"). People - I hate 'em.
Anita Suderman wrote:
> Blue Black Purple submitted by Debbie Altschwager
> Rake cone 08-06 ox or redux.
>
> Gerstley Borate 50
> Neph sy 50
>
> Copper Carb 50 for Tomatoe Red: Copper ox. 20
> Rutile 50 and Red Iron ox.
>
> comments: apply 1 coat. they fire 1830-1900 deg. surface like 100 grit
> sandpaper. Colored from silver blue to silver bronze with flashes of
> color that can run the whole spectrum, lots of bright teal and purple
> with halos of fuschia and mustard, once in a while red
>
One thing that was not mentioned re: this glaze is that the parts are
SUPPOSED to be measured by volume, not by weight. I didn't know this the
first time I made a batch, and did my measurements by weight. We dip
pieces to glaze, and when fired, this glaze peeled off the pot and made
very ugly sharp places to boot.
After that experience I found out that the glaze should have been mixed
by volume, and mixed a new batch. Unfortunately, the "correct" batch
isn't nearly as pretty IMHO as the "wrong" batch (Now dubbed the Magical
Mystery Glaze), which works quite well when brushed on thinly instead of
dipping.
Either way you mix it, the glaze colors up better if you put a clear or
white under or over it.
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