Tommy Humphries on wed 13 feb 02
I remember a while back watching a video of a sanitary ware mfg. line. The
toilets were molded in two pieces and the halves were dried before assembly.
A bead of slip was applied to the joint and the two pieces of greenware
glued together. next step down the line the seam was scraped where the
greenware had absorbed the moisture from the slip, then on to the fire.
Tommy
----- Original Message -----
From: "John Jensen"
To:
Sent: Wednesday, February 13, 2002 4:51 PM
Subject: defloculating slip
I mix up a thick slip with Darvan and sodium silicate. I mix up about five
gallons or so at a time and it lasts awhile. I use it to join clay parts.
My thinking is: less water less shrinkage and I imagine that the chemicals
also defloculate the parts being joined so that there is a melding going on.
Whatever is happening, it works for me. I can even use it sometimes to join
broken greenware.
John Jensen on wed 13 feb 02
I mix up a thick slip with Darvan and sodium silicate. I mix up about =
five gallons or so at a time and it lasts awhile. I use it to join clay =
parts. My thinking is: less water less shrinkage and I imagine that =
the chemicals also defloculate the parts being joined so that there is a =
melding going on. Whatever is happening, it works for me. I can even =
use it sometimes to join broken greenware. =20
I mix a bit intuitively, though at one point I do remember measuring =
something like an ounce or two for a five gallon bucket. I add the =
chemicals to a gallon or maybe two of water and then start throwing in =
chunks of trim clay till the bucket is fairy full. I use an eight gallon =
bucket and fill it about 5/8 full.I leave the mix to sit overnight then =
stir it up with a paint mixing propeller (a big one) on a half inch =
drill. If it seems wet I add more clay, If too thick I add a bit more =
darvan or sodium silicate first then more water if needed. I like a =
slip which is almost as thick as mayonaisse...maybe like ketchup or the =
two mixed.
I've been meaning to make some tests with other methods...such as =
vinegar.
John Jensen
Mudbug Pottery, mudbug@toad.net, Toadhouse.com=20
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