Richard Gralnik on thu 3 sep 98
Doug,
I would add one point to this instruction set -
Keep the jiffy mixer submerged. One thing you don't want to do is
introduce a lot of air bubbles into the plaster.
Richard
At 10:30 AM 8/31/98 EDT, you wrote:
>----------------------------Original message----------------------------
>In reading the idea of making a plaster bucket for scrap reclaim I noticed
>what I believe to be an error in the mixing procedure of the plaster. I
>have made slipcast & Ram press molds for several years and if the
>instructions for mixing plaster are followed it won't be a very
>satisfactory cast.
>The way that USG recommends is the following. A consistancey of 70, ie 7lbs
>of water to 10lbs of plaster. A water temp of 85-95 degrees (F) place the
>water into the container first, then sift in the plaster, not as one would
>flour into a cake mix, but rapidly spreading the plaster over the surface of
>the water perhaps 15 seconds max. Allow to soak/slake for 2 min. Power mix
>with a drill and jiffy mixer of the appropriate size for the batch, for
>2minutes (min) 3 minutes (max) 1700 rpm is the suggested speed but just go
>as fast as your drill will go. At this point pour into the cavitiy, or if
>making the plaster bucket in the original message, get the smaller bucket
>or container into the the larger one and there you go.
>-----Original Message-----
>From: mel jacobson
>To: CLAYART@LSV.UKY.EDU
>Date: Sunday, August 30, 1998 12:57 PM
>Subject: plaster a bushel
>
>
>----------------------------Original message----------------------------
>in reading vince's idea for flat plaster batts it reminded me that for years
>at school i made plaster bushel baskets.
>
>getting water out of vast amounts of re/cycled clay is a bugger. it drove
>me
>semi crazy. (of course i was usually in that state)
>
>i have tried the pants hanging from the ceiling trick and dozens of others,
>but the
>best i ever used was the basket.
>
>take a large plastic bushel basket, feed tub, or other large plastic or
>rubber container,
>oil it lightly or use any technique for release. fill that container 1/2
>full of plaster
>and add the appropriate amount of water. when the plaster is starting to
>set, displace
>it with a smaller pail or round bottomed container filled with sand (or any
>weight). hold it in
>place until it stays. the next day pop the two containers off the plaster
>form and
>you have a great big drying batt that will hold about 80 lbs of clay.
>
>i would dry these containers around the kilns for about a week.
>
>we would line up against a wall, or under tables 5 gallon pails full of
>scrap clay, add water, vinegar and ammonia, and let sit for weeks. when
>that clay got stinky,
>we would just dump the whole 5 gallon pail full of clay into the plaster
>container.
>bingo, three days later it would just drop into the pug mill and you do not
>even
>have to add dry clay to it.....just ready to throw. after years, the
>plaster containers
>would have students names, recipes, ideas and stuff graffitied into them,
>we also
>added old tempera paint to the mix to color code the containers.
>
>older, more experienced students would learn that the stinky clay, from the
>batts,
>was very plastic, could be altered with sand and grog and was the favored
>clay
>in the studio......and then the re/cycling would begin in earnest. (tom
>sawyer)
>of course for all of my demos, or when i made pots for me in the school
>studio,
>i only used old, re/cycled clay, (i never used the boxed clay that was
>purchased
>for student use.)
>
>the other day tom wirt and betsy were over and i was telling them that i
>used the walker
>pug mill for all of my clay, and that i was so used to open clay bodies that
>i throw fresh de/aired clay from continental or minnesota
>right into the pug mill, added
>scrap clay, some dry mix and just run it through a few times and throw
>with it fresh......can't seem to tell the difference........but then i have
>been
>throwing for 45 years.
>
>if you have a home studio and no pug mill, this system is just perfect.
>test the clay in the batt with your finger now and then. when it is
>perfect,
>just turn it out on your wedging table and have a go at it.....then into
>plastic
>bags...ready to roll. all you need is one of these in the corner of your
>studio
>and you will not even think about piles of scrap.
>
>mel/mn
>
>remember, this is a theory, not a recipe...it has about 50 variations
>depending on your needs.
>http://www.pclink.com/melpots
>
>
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