Jonathan Kaplan on sun 8 jun 97
I'd like to get some information regarding glaze additives that some of you
may have used...not limited to but including
CMC, Vegum, Dextrin, PVA, Flocs, Epsom Salts, Macaloid, etc. etc.
ALso, glaze preparation techniques that may or may not include specific
gavity of glazes, ball milling, etc. etc.
for research for an upcoming possible publication.
Any information will be of course credited, and thanks in advance, and as
usual, I'd be most happy to reciprocate.
Jonathan
Jonathan Kaplan http://www.craftweb.com/org/jkaplan/cdg.shtml
http://www.ceramicsoftware.com/education/clay/kaplan1.htm
jonathan@csn.net
Ceramic Design Group Ltd./Production Services Voice:
970-879-9139 POB 775112
FAXmodem: same
Steamboat Springs, Colorado 80477, USA CALL before faxing
"
Louis Katz on mon 9 jun 97
After having problems with Epsom Salts as a flocculant for a glass
slurry, I was told to try 1% Magnesium Carbonate for it's slight
solubility. This seemed to work better than the Epsom Salts. I think that
it was being taken out of solution as some other compound. The Magnesium
Carb provided some backup material.
Bentonite is a good magic bottle kind of material in glazes. I t seems to
help adhesion, toughness of the glaze coat and perhaps most importantly
it limits the amount of water a body can take up, and keeps drips from
showing as thicker areas of a glaze.
As to PEG, antifreeze,propylene glycol, gums and stuff I'll leave this to
others with more experience with them.
Louis
Louis Katz
Texas A&M University Corpus Campus
lkatz@falcon.tamucc.edu
http://www.tamucc.edu/~lkatz
LINDA BLOSSOM on tue 10 jun 97
I use Veegum religeously in my glazes. 1%. I single fire all of my work
and have never met a glaze that wouldn't work as long as I use Veegum. I
used to use CMC but switched to Veegum on the recommendation of Jeff Zamek.
I have Macaloid but it seems to be about the same thing. Also, when I do
any majolica, I add a water and veegum mix to the oxide or stain and it is
hard enough to take handling. No rubbing off.
Linda Blossom
2366 Slaterville Rd.
Ithaca, NY 14850
607-539-7912
blossom@lightlink.com
http://www.artscape.com
"Rafael Molina-Rodriguez (Rafael Molina-Rodriguez)" on tue 10 jun 97
Jonathan :
My choice for a glaze additive is Epsom Salt (Magnesium Sulfate
Heptahydrate). I use it as a suspension material. I usually mix up 10,000
gram batches for my classes. This amount almost fills a 5 gallon container.
I add a tablespoon or two to the glaze. In my experience, it helps keep
the glazes in suspension. Even with some of our glazes that have a tendency
to really cake up at the bottom of the bucket like Woo Blue Brown and Steven
Hill 232 Clear.
I have recently tried using CMC gum over glazes to help with glaze on glaze
decoration (pouring, trailing, brushing, etc.,...). It had a noticeable
effect on the fluid application of one glaze over another. I understand it
can be added to a glaze for the same effect.
Rafael
rmr3431@dcccd.edu
>>> Jonathan Kaplan 06/08/97 09:22pm >>>
----------------------------Original message----------------------------
I'd like to get some information regarding glaze additives that some of you
may have used...not limited to but including
CMC, Vegum, Dextrin, PVA, Flocs, Epsom Salts, Macaloid, etc. etc.
ALso, glaze preparation techniques that may or may not include specific
gavity of glazes, ball milling, etc. etc.
for research for an upcoming possible publication.
Any information will be of course credited, and thanks in advance, and as
usual, I'd be most happy to reciprocate.
Jonathan
Jonathan Kaplan http://www.craftweb.com/org/jkaplan/cdg.shtml
http://www.ceramicsoftware.com/education/clay/kaplan1.htm
jonathan@csn.net
Ceramic Design Group Ltd./Production Services Voice:
970-879-9139 POB 775112
FAXmodem: same
Steamboat Springs, Colorado 80477, USA CALL before
faxing
"
Grimmer on wed 11 jun 97
Hi,
Another good additive is Muriatic acid, aka HCl, hydrochloric acid.
It is a potent flocculant, and does not contribute solubles to the
slurry. I'm guessing that some Cl will join with RO/RO2 to form some
soluble salts, but I haven't seen any evidence of this.
It is also great as an additive to joining water in place of vinegar.
As there are no organics present, it doesn't contribute to 'studio sour.'
Caveats: HCL is a *strong* acid. Wear goggles/gloves when dealing with
the stuff straight.
It's best to make a 50/50 solution of HCl and H2O for general use. ALWAYS
add acid to water, never water to acid.
A couple of drops of this mix will suspend even the most troublesome
glazes. Add maybe a tablespoon for 5 KG galze. You will notice the slurry
visibly thicken as you mix. A couple of drops in joining water really cuts
down on cracking.
steve grimmer
carterville, illinois
Grace Liu on wed 11 jun 97
Linda,
>>I use Veegum religeously in my glazes.
At the risk of sounding very ignorant, may I ask what Veegum is? I'm guessing
it's a brand name in the US. What is the actual material, and where can I find
it (in the States), though I'm from Hong Kong?
I do alot of on-glaze decoration and think this may solve alot of headaches.
I'd like to try it out.
Thanks in advance for your advice!
grace
LINDA BLOSSOM on thu 12 jun 97
Veegum Cer is a synthetic gum. You might find that your supplier carries
CMC - also a synthetic gum. You could probably use gum arabic but it has a
shorter shelf life. Look in the catalogs under glaze ingredients. Laguna
carries it and I would expect ART and Axner to also carry it. Be sure to
add it dry to glazes and sieve the glaze. When adding to water, I used a
hand held blend to mix it in. You must mix it well. It keeps well and can
be used instead of plain water for majolica work.
Linda Blossom
2366 Slaterville Rd.
Ithaca, NY 14850
607-539-7912
blossom@lightlink.com
http://www.artscape.com
Tony Hansen on thu 12 jun 97
> At the risk of sounding very ignorant, may I ask what Veegum is?
At the risk of sounding ignorant I'll try to answer!
Veegum is a complex colloidal and extremely plastic magnesium aluminum
silicate.
It is an off-white insoluble flake magnesium aluminum silicate that
swells to
many times its original volume when added to water. Its aqueous
dispersions are
thus high viscosity thixotropic gels at low solids. Veegum is not suject
to
attack by microorganisms. Various grades are classified according to
viscosity
and ratio of aluminum to magnesium content.
Veegum T is used as a suspending agent and surface hardener for glazes,
as a plasticizing agent for nonplastic formulations such as high alumina
or zirconia bodies, and as a nonmigrating binder in extruded bodies. It
is valuable in once-glaze applications to prevent crawling. The material
is white and therefore does not affect fired whiteness. It has a high
pH of 8.5 and yet acts as a flocculant, contributing to the workability
of porcelain. About 2% added to a porcelain yeilds good results.
Veegum CER is a mixture of Veegum T and medium viscosity sodium
carboxymethylcellulose that gives optimum surface hardening of unfired
ceramic glazes for safe handling of the ware. It serves as hardener,
suspending agent and viscosity stabilizer in glazes.
Veegum Pro is Veegum treated with amine to improve dispersability.
Veegum Pro hydrates readily in hot or cold water to form high viscosity
dispersions. Recommended for use where a minimum amount of water is
required and/or only slow type mixers are available.
Other Grades: F, HV, K, S728, HS
--
=================================================================
Tony Hansen, IMC thansen@mlc.awinc.com
INSIGHT5/Magic of Fire II demos at www.ceramicsoftware.com
Karl P. Platt on thu 12 jun 97
> Another good additive is Muriatic acid, aka HCl, hydrochloric acid.
>It is a potent flocculant, and does not contribute solubles to the
>slurry. I'm guessing that some Cl will join with RO/RO2 to form some
>soluble salts, but I haven't seen any evidence of this.
HCl is a lousy additive to slip for a lot of reasons. Cl does not form
any sort of reaction with RO/R20 as described.
Grimmer on fri 13 jun 97
Karl P. Platt wrote:
> HCl is a lousy additive to slip for a lot of reasons. Cl does not form
> any sort of reaction with RO/R20 as described.
Indeed, lousy in slip. Good in glaze.
steve grimmer
carterville illinois.
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