Cindy or Tiffanie on sun 23 feb 97
Karen and Denise,
I, too, have had trouble with the "quick release" bat molds. Part of the
problem is, I know, that I've had no experience in making plaster bats. No
matter how good the instructions may be, a certain amount of practice (and
failure) is required to get good at most anything. I bought mine from
Axner, so if any Axner folks are reading this, maybe they can help. I've
found that the triangle-shaped "key" which holds the bat to the wheel head
creates a suction so that I can't remove my bat easily without also
removing the wheel head adapter. This is really a problem for large
bowls/platters/casseroles. In an attempt to resolve this, I gouge out air
ducts leading from the key to the edge of the bat while the plaster is
still soft. Naturally, this is a pain in the neck and makes a mess, but it
does seem to help a little. Sometimes the bats still stick, but not as
frequently.
As to leveling the bat mold, I've found that if I place my carpenter's
level first parallel, and then perpendicular, I have no trouble with wobbly
bats. Note--I don't level the table--I level the bat mold.
According to the instructions, the plaster should be left in the mold no
longer than 20 minutes or so. In my (limited) experience, trying to take
the bat out of the mold at this point is an invitation to disaster. I leave
it in for at least a couple of hours.
My last difficulty with the mold system is that the bats must be so very
large. I'd like to be able to make smaller bats for items such as cups,
bowls, vases, etc. The large bats are wonderful for huge platters, etc.,
but they do take up a lot of space and seem to be overkill for small items.
Cindy
Jeremy/Bonnie Hellman on mon 24 feb 97
Hello, Cindy and others.
First off, my disclaimer. I have no experience with the quick release
system. However I have made plaster bats using a variety of "molds".
I've used my favorite pie pans, lined with plastic wrap- which works fine
except that I always get wrinkles on the bottoms of my bats. Aethetically
ugly, but no noticeable impact on function. I always work on a level
surface, leveled in all directions using a commercial level.
I've also used aluminum "throw away" "one use" pie pans (used many times)
and because they flex, I've been able to get my plaster bats out easily.
However my real favorite is using cheap, round plastic buckets. Cheap is
good because the plastic is usually thinner rather than thicker, and also
because they flex, so you can get the bats out. The buckets are sometimes
deep, so that I try to cushion the flat surface onto which the bat will
fall, when the bucket is turned upside down and released. You just have
to be sure that the sides of the bucket slant outward or at least
straight!
The other point is that I used to buy whatever plaster happened to be
sold in the paint store. Let me say from personal experience that not all
plasters are the same. There have previously been long discussions about
the different types of plaster, and some clay suppliers sell a variety of
"plasters" which I am using as a generic name. Shrinkage is one of the
main differences. I wonder if part of the problem in making bats from the
molds is related to the type of plaster being used. Just a thought
because I've noticed a wide variation in the amount of heat generated as
plaster sets, along with a wide variation in the amount of shrinkage. I
would think you would want at least some shrinkage, to help remove the
plaster from the bat mold.
Then, after making all those bats, I was given a set of the Jepson bats
with his plastic rings that anchor to the screw heads on my Brent wheel.
No more attaching my plaster bats with slip, which worked well most of
the time, but not always. No more agonies of trying to re-center. Great
system. I'd love to be able to make my own bats to fit his system,
instead of having to buy his!
Bonnie Hellman in Pittsburgh, PA
>
>I, too, have had trouble with the "quick release" bat molds. Part of the
>problem is, I know, that I've had no experience in making plaster bats. No
>matter how good the instructions may be, a certain amount of practice (and
>failure) is required to get good at most anything. I bought mine from
>Axner, so if any Axner folks are reading this, maybe they can help. I've
>found that the triangle-shaped "key" which holds the bat to the wheel head
>creates a suction so that I can't remove my bat easily without also
>removing the wheel head adapter. This is really a problem for large
>bowls/platters/casseroles. In an attempt to resolve this, I gouge out air
>ducts leading from the key to the edge of the bat while the plaster is
>still soft. Naturally, this is a pain in the neck and makes a mess, but it
>does seem to help a little. Sometimes the bats still stick, but not as
>frequently.
>
>As to leveling the bat mold, I've found that if I place my carpenter's
>level first parallel, and then perpendicular, I have no trouble with wobbly
>bats. Note--I don't level the table--I level the bat mold.
>
>According to the instructions, the plaster should be left in the mold no
>longer than 20 minutes or so. In my (limited) experience, trying to take
>the bat out of the mold at this point is an invitation to disaster. I leave
>it in for at least a couple of hours.
>
>My last difficulty with the mold system is that the bats must be so very
>large. I'd like to be able to make smaller bats for items such as cups,
>bowls, vases, etc. The large bats are wonderful for huge platters, etc.,
>but they do take up a lot of space and seem to be overkill for small items.
>
>Cindy
"Very funny, Scotty. Now beam down my clothes!" Capt. J. Kirk
"Outside a dog, a book is a man's best friend. Inside a dog, it's too
dark to read" Groucho Marx
" " Harpo Marx
"Time flies like an arrow. Fruit flies like an avocado" Att. to GM
Clay on mon 24 feb 97
I never used those batt or mould before. However I recognize you have some
plaster problem that's for sure.
Now listen!
Plaster only dry faster (10-20minutes) if you mixed it long enough .
for press mould 100parts of water mixed with 140parts of plaster.
Yeah right , alot of people say you properly dump to use a scale to weight
plaster.I tell you what, I make mould for years & I still use a scale.
Mix it for 6 minutes by hand(by mixer usually seting time will be too fast
and you get all sizes of air bubbles.
only room temperature water can be use. too hot you will get a huge expension.
I am using USG No.1 pottery plaster. I found that plaster of paris is
setting too fast,& too soft.
At 10:18 AM 2/23/97 EST, you wrote:
>----------------------------Original message----------------------------
>Karen and Denise,
>
>I, too, have had trouble with the "quick release" bat molds. Part of the
>problem is, I know, that I've had no experience in making plaster bats. No
>matter how good the instructions may be, a certain amount of practice (and
>failure) is required to get good at most anything. I bought mine from
>Axner, so if any Axner folks are reading this, maybe they can help. I've
>found that the triangle-shaped "key" which holds the bat to the wheel head
>creates a suction so that I can't remove my bat easily without also
>removing the wheel head adapter. This is really a problem for large
>bowls/platters/casseroles. In an attempt to resolve this, I gouge out air
>ducts leading from the key to the edge of the bat while the plaster is
>still soft. Naturally, this is a pain in the neck and makes a mess, but it
>does seem to help a little. Sometimes the bats still stick, but not as
>frequently.
>
>As to leveling the bat mold, I've found that if I place my carpenter's
>level first parallel, and then perpendicular, I have no trouble with wobbly
>bats. Note--I don't level the table--I level the bat mold.
>
>According to the instructions, the plaster should be left in the mold no
>longer than 20 minutes or so. In my (limited) experience, trying to take
>the bat out of the mold at this point is an invitation to disaster. I leave
>it in for at least a couple of hours.
>
>My last difficulty with the mold system is that the bats must be so very
>large. I'd like to be able to make smaller bats for items such as cups,
>bowls, vases, etc. The large bats are wonderful for huge platters, etc.,
>but they do take up a lot of space and seem to be overkill for small items.
>
>Cindy
>
Jonathan Kaplan on tue 25 feb 97
Need to jump in here and make some corrections about plaster.
Use the correct water to plaster ratio. Don't just dump it in until it
looks right. There is so much uneducated and mis-information and fear about
working with plaster that if we continue to pass on this bad information,
it won't help anyone.
Weigh the water, weigh the plaster. Use a USG Plaster/Volume and Mix
Calculator available form US Gypsum in Chicago. Used correctly, this simple
slide rule device will provide all the info you'll ever require to
accurately mix plaster.
The correct water to plaster ratio for USG Pottery #1 plaster is 70 parts
water to 100 pounds plaster. Each of their products require a different
ratio.
Jonathan
Jonathan Kaplan
Ceramic Design Group Ltd./Production Services
PO Box 775112
Steamboat Springs CO 80477
jonathan@csn.net
(970) 879-9139*voice and fax
http://www.craftweb.com/org/jkaplan/cdg.shtml
Jonathan Kaplan on tue 25 feb 97
Need to jump in here and make some corrections about plaster.
Use the correct water to plaster ratio. Don't just dump it in until it
looks right. There is so much uneducated and mis-information and fear about
working with plaster that if we continue to pass on this bad information,
it won't help anyone.
Weigh the water, weigh the plaster. Use a USG Plaster/Volume and Mix
Calculator available form US Gypsum in Chicago. Used correctly, this simple
slide rule device will provide all the info you'll ever require to
accurately mix plaster.
The correct water to plaster ratio for USG Pottery #1 plaster is 70 parts
water to 100 pounds plaster. Each of their products require a different
ratio.
Just fortgot to add that the soak time and mix time is crutial for optimum
plaster strength and longivity. In our mold shop, we soak the correct
amount of plaster in the correct amount of water for 2.5 minutes and then
mix for 2.5 minutes, then pour over a sharp edge to break any entrapped
air.
Jonathan
Jonathan Kaplan
Ceramic Design Group Ltd./Production Services
PO Box 775112
Steamboat Springs CO 80477
jonathan@csn.net
(970) 879-9139*voice and fax
http://www.craftweb.com/org/jkaplan/cdg.shtml
Ya-Shih_Hart/CAM/Lotus@lotus.com on tue 25 feb 97
Hi all,
Thanks to all the people who responded to my questions about plaster bat
molds, after speaking to Sheila Jenkins, the inventor of slumphump(tm) I
have decided to give it a try. Sheila would like to here from those who
have problems with her product. you can reach her at 800-363-3397 or write
to her at SheilaJ329@aol.com.
Thanks,
Ya-Shih Hart
Ric Swenson on wed 26 feb 97
>----------------------------Original message----------------------------
>Need to jump in here and make some corrections about plaster.
>
>Use the correct water to plaster ratio. Don't just dump it in until it
>looks right. There is so much uneducated and mis-information and fear about
>working with plaster that if we continue to pass on this bad information,
>it won't help anyone.
>
>Weigh the water, weigh the plaster. Use a USG Plaster/Volume and Mix
>Calculator available form US Gypsum in Chicago. Used correctly, this simple
>slide rule device will provide all the info you'll ever require to
>accurately mix plaster.
>
>The correct water to plaster ratio for USG Pottery #1 plaster is 70 parts
>water to 100 pounds plaster. Each of their products require a different
>ratio.
>
>Just fortgot to add that the soak time and mix time is crutial for optimum
>plaster strength and longivity. In our mold shop, we soak the correct
>amount of plaster in the correct amount of water for 2.5 minutes and then
>mix for 2.5 minutes, then pour over a sharp edge to break any entrapped
>air.
>
>Jonathan
>
>
>
>Jonathan Kaplan
>Ceramic Design Group Ltd./Production Services
>PO Box 775112
>Steamboat Springs CO 80477
>
>jonathan@csn.net
>(970) 879-9139*voice and fax
>http://www.craftweb.com/org/jkaplan/cdg.shtml
--------reply--------
GOOD ADVICE !
The only things I would add, would be to also watch the TEMPERATURE of the
water...go by GP or USG guides...and to use the proper type (shape) and
speed of mixer blade. This is really important when doing RAM dies. (I had
12 years experience at Bennington Potters.)
As I think of it...also..."never" pour left over plaster down a sink drain!
Make sculptures of it!.... quickly!
Enjoy!
Ric Swenson, Bennington, Vermont
Cindy on wed 26 feb 97
Hello, Jonathan et al.
I'm using a mold-making plaster which is what the folks at our local
ceramic shop recommended and sold me--don't know if that's designated as #1
or what, but I'll check. As for weighing the water, etc., the mold comes
with very specific instructions to add so much plaster, so much H2O by
weight, and that's what I've been doing. There is no discernible shrinkage.
They also recommend mixing with an electric paint stirrer, so I've been
doing so. After allowing the particles to get wet for a few minutes, then
mixing by hand, I use my paint mixer on my little electric drill. Maybe I
need to get one of those fancy $30 glaze mixers or have the local
blacksmith make me something that will agitate better than the mixer I'm
using?
Thanks for the help,
Cindy :-)
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