Michael Wendt on sun 9 mar 03

Waltraud,
It sounds like you have a leak in the vacuum chamber. If you have access to
silicone rubber caulking, try running a thin bead around all the joints into
the vacuum chamber and wait a few hours, then try the thing again. One time,
I thought I had a failed vacuum pump when all I had was a vacuum line leak.
Once I fixed that, I got high vacuums again and my clay was very much
improved.
Good Luck und es freut mich dass wir jemand aus Deutschland am List haben.
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Avenue
Lewiston, Idaho 83501
1-208-746-3724
wendtpottery.com

Tommy Humphries on sun 9 mar 03

This is a CLASSIC example not enough vacuum in your
mill, find the leak, either at the cover of the vacuum
chamber, or at the seam of the barrel. Often a bit of
dry clay, or grit from the clay will wedge itself into
the seams and prevent a good seal.

Tommy Humphries


--- Waltraud Koestler wrote:

---------------------------------
Hello all,

I bought a Venco vacuum pugmill (3"), because I would
like to recycle
porcelain clay (trimmings, failed throwings, mixing
different types
of porcelain bodies together).

The problem ist, that the de-airing and packing
process is not
successful.

The extruded porcelain body comes out with a
consistency of a bread
loaf. I tried two types of porcelain clay, Limoges
TM10 and David
Leach porcelain.
The Limoges TM10 is very loosely packed. One can
unwind layer by
layer from the extruded body. The David Leach
porcelain comes out a
little better, but it's also loosely packed and
sometimes there are
air bullbles in the middle of the extruded string.

The supplier of the venco pugmill recommends for
de-airing fine
porcelain or soft clay to slow down the rate of clay
flow to improve
the deairing process.This can be done by blanking off
the top 2" of
the stainless steel screen.
I tried this, but without substantial success.
I tried to process the body more than one time, also
without success.
The vaccuum gauge reached only 65 to 75 kPa, not more.

It should read 90 kPa as a minimum, better 95 to 98
kPa.

I couldn't find anything in the archives or bookes
about this problem.

Could someone help me to solve this problem?

Thank you!!

regards
Waltraud














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Culling on tue 11 mar 03

Sounds to me as though you have an air leak somewhere in the barrell- =
needs to be opened up and resealed. There is mention of what to do in =
the paperwork I got tho it's not the clearest in the world. The other =
thing when you've done it and done your first pug, let it sit a bit as a =
skin of clay will buildup over very small leaks. trouble is the air is =
suked in so a bit tricky to find the culprit!!
Good luck
Steph

in the sunny Pilbara where we have now had 6 showers of rain in 18 =
months and the rainwater tank is 1/2 full and the humidity has gone sky =
high
----- Original Message -----=20
From: Waltraud Koestler=20
To: CLAYART@LSV.CERAMICS.ORG=20
Sent: Sunday, March 09, 2003 6:59 PM
Subject: Problem with de-airing porcelain clay


Hello all,

I bought a Venco vacuum pugmill (3"), because I would like to =
recycle=20
porcelain clay (trimmings, failed throwings, mixing different =
types=20
of porcelain bodies together).

The problem ist, that the de-airing and packing process is not=20
successful.

The extruded porcelain body comes out with a consistency of a =
bread=20
loaf. I tried two types of porcelain clay, Limoges TM10 and David=20
Leach porcelain.=20
The Limoges TM10 is very loosely packed. One can unwind layer by=20
layer from the extruded body. The David Leach porcelain comes out =
a=20
little better, but it's also loosely packed and sometimes there =
are=20
air bullbles in the middle of the extruded string.

The supplier of the venco pugmill recommends for de-airing fine=20
porcelain or soft clay to slow down the rate of clay flow to =
improve=20
the deairing process.This can be done by blanking off the top 2" =
of=20
the stainless steel screen.=20
I tried this, but without substantial success.
I tried to process the body more than one time, also without =
success.
The vaccuum gauge reached only 65 to 75 kPa, not more.=20
It should read 90 kPa as a minimum, better 95 to 98 kPa.

I couldn't find anything in the archives or bookes about this =
problem.

Could someone help me to solve this problem?

Thank you!!

regards=20
Waltraud














http://www.planet-b.net - Das Internetportal f=FCr =
Bertelsmann-Mitarbeiter und Ihre Familien.=20

=
_________________________________________________________________________=
_____ Send postings to clayart@lsv.ceramics.org You may look at the =
archives for the list or change your subscription settings from =
http://www.ceramics.org/clayart/ Moderator of the list is Mel Jacobson =
who may be reached at melpots@pclink.com.