Jonathan Kaplan on tue 26 sep 00
>I am having trouble trying to recycle my cone 10 Porcelain body. Four equal
>parts by weight:
>EPK
>ball clay OM
>silica
>custer feldspar
> I have a few questions. With stoneware, my understanding is that you loose
>silica in working the clay. Is that also true with Porcelain? I do mix up
>the body dry and add that to the clay I am recycling but I am still coming up
>with a body that is really short. I have concluded that I need to add more
>"something" to the mix. EPK? Silica? Ball Clay? Any suggestions? TIA
>
Drop the EPK for Tile 6 and find a better ball clay than Old Mine #4. Try
Starcast from United Clays or one of the light firing clean balls calys
from Old Hickory. Add a small percentage of Macaloid or Hectorite and you
will notice quite an improvement.
I am not sure what you mean by loosing silica in working with the clay.
Trust me, all the stuff is still in there.
Some porcelains tend to be non plastic and quite short and need some
plasticizing.
Jonathan
Jonathan Kaplan, president
Ceramic Design Group
PO Box 775112
Steamboat Springs CO 80477
voice and fax 970 879-9139
jonathan@csn,net
http://www.sni.net/ceramicdesigin
Plant Location:
1280 13th Street Unit 13
Steamboat Springs CO 80487
(please use this address for all deliveries via UPS, comman carrier, FEd
Ex, etc.)
J102551@AOL.COM on tue 26 sep 00
I am having trouble trying to recycle my cone 10 Porcelain body. Four equal
parts by weight:
EPK
ball clay OM
silica
custer feldspar
I have a few questions. With stoneware, my understanding is that you loose
silica in working the clay. Is that also true with Porcelain? I do mix up
the body dry and add that to the clay I am recycling but I am still coming up
with a body that is really short. I have concluded that I need to add more
"something" to the mix. EPK? Silica? Ball Clay? Any suggestions? TIA
Jeri
June Perry on tue 26 sep 00
Jeri, you can try adding 1 1/2 - 2% V gum T. First blunge the gum in water
overnight, mix well and then mix it in with your clay.
Adding some acid like citrus or wine or beer can increase plasticity short
term.
It's a good idea to save your throwing water and add that to you reclaimed
clay.
Regards,
June
vince pitelka on tue 26 sep 00
> I have a few questions. With stoneware, my understanding is that you
loose
> silica in working the clay. Is that also true with Porcelain? I do mix
up
> the body dry and add that to the clay I am recycling but I am still coming
up
> with a body that is really short. I have concluded that I need to add
more
> "something" to the mix. EPK? Silica? Ball Clay? Any suggestions? TIA
Jeri -
Might just need flocculation. Feldspars release alkalinity into solution
over time, deflocculating the clay, making it short. You need to counteract
that, and it is very easy to do. Also, dry kaolins are sometimes slightly
alkaline. Many are the short porcelain and whiteware bodies which have been
discarded as unworkable, when they could so easily have been salvaged.
Go to your local pharmacy and buy a half-gallon carton of epsom salts for a
few bucks. It is very cheap stuff. Mix up a saturated solution of epsom
salts. To a pint or so of very hot water, add epsom salts, mixing
constantly (one of those little hand-blenders makes short work of this),
until no more will dissolve. Put that in a squirt bottle - like a hair-dye
bottle. Take a sampling of the short clay, poke some holes in it, and
squirt just a very little of the epsom salt solution into it, and then wedge
it thoroughly. It should become much more plastic.
When you recycle your clay, you are no doubt slaking it down and decanting
off the water after it settles, leaving a thick slurry, which will be about
30% water. Weigh your recycle, and subtrct 30% of the weight, giving you
the approximate dry-materials weight. Multiply that by 1/2 of 1% to get the
amount of epsom salts to use. If you are adding dry-mix clay, add that
weight to the above before figuring the percentage epsom salts addition.
Dissolve the epsom salts in a small amount of hot water, and mix that into
your slurry with a drill-mixer. Add your dry materials, and let it all
stiffen to working consistency and you should have delicious clay.
Don't use the dry materials to GET the clay to working consistency, or you
will have very non-plastic clay (at least until it ages). Mix it very wet -
like a thick slurry, and then dry it to working consistency. That will wet
all the particles much more thoroughly and you will end up with much more
workable clay.
Good luck -
- Vince
Vince Pitelka
Home - vpitelka@dekalb.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
http://www.craftcenter.tntech.edu/
Ron Roy on tue 3 oct 00
I use a similar body at cone 10. The trick is to let the trimmings dry out
completely - just add water and it will be OK as is.
I prefer EPK - in fact I manage several porcelains and have found that clay
to be reliable and sevicable. I have years of tests on the raw material and
it is the whitest of all the kaolins we use.
I have found the Tile 6 to be less reliable and not as white.
I do recommend adding 2% bentonite to the above body - strength and
plasticity are both improved.
RR
>>I am having trouble trying to recycle my cone 10 Porcelain body. Four equal
>>parts by weight:
>>EPK
>>ball clay OM
>>silica
>>custer feldspar
>> I have a few questions. With stoneware, my understanding is that you loose
>>silica in working the clay. Is that also true with Porcelain? I do mix up
>>the body dry and add that to the clay I am recycling but I am still coming up
>>with a body that is really short. I have concluded that I need to add more
>>"something" to the mix. EPK? Silica? Ball Clay? Any suggestions? TIA
>
>Drop the EPK for Tile 6 and find a better ball clay than Old Mine #4. Try
>Starcast from United Clays or one of the light firing clean balls calys
>from Old Hickory. Add a small percentage of Macaloid or Hectorite and you
>will notice quite an improvement.
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
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