Lee Love on thu 23 sep 10
On Thu, Sep 23, 2010 at 8:14 PM, Mike Barber wrote=
=3D
:
> Hi all,
> I'm looking for some advice about on pug mills. I like the looks and idea=
=3D
(no
> vacuum) of the Shimpo NRA-04 pug mill. Part of the pitch is that it's dua=
=3D
l
> auger system produces "practically air-free clay"
Mike, I used one in Mashiko. It isn't a dearing pugmill. For the
same price you can get what I use, a Bluebird 440 deairing pugmill:
http://www.axner.com/bluebird-model-440-studio-deairing-pugmill.aspx
--
=3DA0Lee, a Mashiko potter in Minneapolis
http://mingeisota.blogspot.com/
=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi
Mike Barber on thu 23 sep 10
Hi all,
I'm looking for some advice about on pug mills. I like the looks and idea=
=3D
(no=3D20
vacuum) of the Shimpo NRA-04 pug mill. Part of the pitch is that it's dua=
=3D
l=3D20
auger system produces "practically air-free clay". However all I can find=
=3D
on the=3D20
internet is the same sales literature. I haven't been able to discern=3D20
whether "practially air-free clay" means that I could just pug and throw,=
=3D
or=3D20
whether it requires further wedging.=3D20
Has anyone used one that throws on the wheel? How do you like it? Any=3D20
advice would be appreciated.=3D20
Thanks!
Mike Barber
www.GlazeCalculator.com
Clyde Tullis on fri 24 sep 10
Mike, I use an old stainless Bluebird Studio model (no de-air). Flat war=
=3D
e
needs a few pushes on the table to get some air out but everything else i=
=3D
s
pretty much usable straight out of the machine. I've got friend that has=
=3D
the shimpo and it works great but it is a pain in comparison when it come=
=3D
s
to switching clays.
ivor and olive lewis on fri 24 sep 10
Dear Mike Barber,
You ask...."I haven't been able to discern whether "practically air-free
clay" means that I could just pug and throw, or whether it requires further
wedging."
A couple of years ago I asked about the nature or composition of exhaust
gases from De-Airing Pugmill. As I recall no one had ever taken the time to
have exhausted de-airing pugmill gases analysed.
I reasoned that unless a volume of air was trapped inside the feedstock or
was entrained by feedstock as it entered the pug mill the volume of Air
would be relatively small. In contrast there would be varying proportions o=
f
other gases which would be small but significant. My predictions were that:
1. There would be Oxygen and Nitrogen, not in the proportions found in
Earths atmosphere but in the proportions in which those two gases dissolve
in Water: 2. There would be a proportion of moisture, as water vapour; 3,
There would be a volume of Carbon dioxide which had been dissolved in the
water fraction.
I have my own ideas about the influence the presence or absence such
inclusions might have on plastic clay. So I suggest those who consider they
have a greater depth of knowledge and experience than I might like to add
their few cent's worth of enlightenment.
But in regard to your direct question. In my opinion, if the proportion of
water to solids in a plastic clay body is within the range of workability
for studio processes then a well "de-aired clay" would be more responsive
than the same clay that has not been treated in this manner. I would
anticipate the working properties of Vacuum Exhausted Clay should be
superior to that prepared manually.
Best regards,
Ivor Lewis,
REDHILL,
South Australia
Larry Kruzan on fri 24 sep 10
Firstly, truth in advertising - I am=3DC2=3DA0the happy owner of a=3DC2=3DA=
0Peter P=3D
ugger VPM-60=3D20
There is a world of difference between a pugmill and a mixer/wedger like th=
=3D
e PP. I have owned both types and can sum up the differences real quick. Th=
=3D
e owner of a pugmill uses the machine to do 20% of the work required to rec=
=3D
ycle clay - you do the rest. The owner of a PP Power wedger as they call it=
=3D
, uses the machine to do all the work.=3D20
First the pug mill process.=3D20
If your scrap is dry, you have to slake it down first and get the consisten=
=3D
cy right by drying it to what your pug mill likes. A pug mill will not feed=
=3D
clay that is too soft or too hard. Next you cut the clay lump into small e=
=3D
nough chunks that will fit into the small mouth of the pugmill. As the mach=
=3D
ine is running you press clay into the mouth - when you stop feeding it cla=
=3D
y stops moving through the machine. IF the clay is not completely mixed you=
=3D
feed it back through again and again until it is mixed. The top-end Shimpo=
=3D
appears to do this better than most, but I've only been a spectator with t=
=3D
hem.=3D20
Before all the hysterics start - I know there are LOTS of machines out ther=
=3D
e that do way more or less of the work, will feed themselves, feed the dog =
=3D
and the baby and mow the lawn and change it's diaper - the baby, not the la=
=3D
wn. I'm listing GENERAL, basic=3DC2=3DA0facts about pugmills.=3D20
When I bought my FIRST=3DC2=3DA0Pug Mill=3DC2=3DA0I really had never seen o=
ne work.=3D
I had used a PP in school and thought that it was a pugmill (it is, sorta =
=3D
- like comparing a kite to a jet=3DC2=3DA0airplane) All=3DC2=3DA0I knew was=
that I =3D
needed help with clay scrap and all I have heard about was a "Pug Mill". By=
=3D
the time I discovered it was the wrong machine and got rid of it, I lost a=
=3D
couple THOUSAND dollars. NOT chump change.=3D20
The owner of a machine like the PP puts in clay (dry, wet, mixed slop, what=
=3D
ever) presses a button, waits 15-20 minutes, decides if it needs a little m=
=3D
ore or less water, adds a little dry clay or water and pushes the button ag=
=3D
ain!!! Checking it in a few minutes and repeat again as needed, once the mi=
=3D
x is the way you want it,=3DC2=3DA0you=3DC2=3DA0vacuum the air out the whol=
e batch =3D
by pressing another button. (the folks at PP really need to get the button=
=3D
=3DC2=3DA0thing under Control!! this is hard work!!)=3DC2=3DA0The operator =
then=3DC2=3D
=3DA0presses a third button and watches perfectly blended, deaired, wedged=
=3DC2=3D
=3DA0clay come out, ready to go on the wheel. The operator then presses ano=
th=3D
er button - the stop button - is your button finger worn out yet???=3D20
This may be a little exaggerated, but not much.=3D20
I've watched the Shimpo being demoed at various shows and it does work nice=
=3D
but it is just a pugmill, you must do most of the work to get everything "=
=3D
just right" for the output to be "just right" - there is no free lunch.=3D2=
0
Let the hyperventilating begin!!!!!!=3D20
Larry Kruzan=3D20
Lost Creek Pottery=3D20
----- Original Message -----=3D20
From: "Mike Barber" =3D20
To: Clayart@LSV.CERAMICS.ORG=3D20
Sent: Thursday, September 23, 2010 8:14:03 PM=3D20
Subject: Pug mill advice=3D20
Hi all,=3D20
I'm looking for some advice about on pug mills. I like the looks and idea (=
=3D
no=3D20
vacuum) of the Shimpo NRA-04 pug mill. Part of the pitch is that it's dual=
=3D
=3D20
auger system produces "practically air-free clay". However all I can find o=
=3D
n the=3D20
internet is the same sales literature. I haven't been able to discern=3D20
whether "practially air-free clay" means that I could just pug and throw, o=
=3D
r=3D20
whether it requires further wedging.=3D20
Has anyone used one that throws on the wheel? How do you like it? Any=3D20
advice would be appreciated.=3D20
Thanks!=3D20
Mike Barber=3D20
www.GlazeCalculator.com=3D20
Vince Pitelka on fri 24 sep 10
Mike Barber wrote:
"I'm looking for some advice about on pug mills. I like the looks and idea
(no
vacuum) of the Shimpo NRA-04 pug mill. Part of the pitch is that it's dual
auger system produces "practically air-free clay". However all I can find o=
n
the
internet is the same sales literature. I haven't been able to discern
whether "practially air-free clay" means that I could just pug and throw, o=
r
whether it requires further wedging."
Hi Mike -
At the Appalachian Center for Craft, most of our clay gets processed throug=
h
a Bluebird non-deairing, and it all has to be wedged thoroughly. When I wa=
s
a full-time potter I built a Harry Davis vacuum-deairing pugmill and used i=
t
to process all of my clay, and I never had to hand-wedge. It was beautiful
clay to throw. I do not think that a non-deairing pugmill is capable of
extracting enough air from the clay. You need a deairing to accomplish
that.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka
Lis Allison on fri 24 sep 10
On September 23, 2010, Larry Kruzan wrote:
>
>
> There is a world of difference between a pugmill and a mixer/wedger
> like the PP.
Amen!
I once borrowed the use of a pugmill for a day and never worked so hard
in my life! I decided it was actually less work, and easier work, to do it
by hand. I put all my clay scraps/slip into large buckets with enough
water to cover, and scoop it out onto plaster batts whenever the buckets
are getting too full. Then I wait until the mix on the batts is stiff
enough and bag it. When I go to throw, I mix some new clay and some of the
re-cycled stuff to the consistency I want and wedge.
Since I like my clay softer than what comes from the supplier, this works
fine for me. It's not as though I throw hundreds of pounds a day!
Lis
--
Elisabeth Allison
Pine Ridge Studio
website: www.pine-ridge.ca
Pottery blog: www.studio-on-the-ridge.blogspot.com
Garden blog: www.garden-on-the-ridge.blogspot.com
Bonnie Staffel on sat 25 sep 10
I have my own take on using a non-deairing pug mill. I have an ancient
Bluebird that I have used since the 60s. IMO feeding this pug mill to =3D
result
in no air pockets is in how one feeds it. I run my clay through it =3D
non-stop
at least three times and when cutting through the extrusion, I never see =
=3D
any
pockets. However, I can understand minute pockets that may make the clay
more usable right out of the deairing pug mill, but with my own method, =3D
I
use mine from the pug mill right to the wheel with no problems. Maybe =3D
the
type of clay body one uses has to be of concern, but I haven't wedged =3D
clay
for years after putting it through the pugger. My Bluebird luckily has =3D
the
wider hopper so that I can add the whole three inch extrusion for =3D
repeated
runs as opposed to the very small hopper opening required in later =3D
models
for safety of school students. With the later changes, one has to cut up =
=3D
the
chunks of clay into smaller pieces which is a bother and probably allows =
=3D
air
bubbles to occur in a non-deairing pug mill. Even so, with a good rhythm =
=3D
to
the feeding, the potter can get a fairly fast workout and a good blend
without having to wedge the clay after the process.=3D20
=3D20
I worked with a friend in his studio for three weeks where he had the =3D
newer
Bluebird without deairing and we worked out the process so that we were
throwing our 25" tall pots as shown on my website. I was able to make =3D
one a
day for two weeks and then we subjected them to the pit fire. It was an
exhilarating time.
=3D20
Bonnie Staffel
http://webpages.charter.net/bstaffel/
http://vasefinder.com/bstaffelgallery1.html
DVD Throwing with Coils and Slabs
DVD Introduction to Wheel Work
Charter Member Potters Council
=3D20
Mike Barber on sat 25 sep 10
All,
I appreciate very much all of the responses. It helps a great deal to hea=
=3D
r from=3D20
all of you on this.
Mike Barber
www.GlazeCalculator.com
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