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what's in your pugmill?

updated thu 5 aug 10

 

Dale Neese on tue 3 aug 10


I was doing a bit of pugmill maintenance yesterday that I usually perform
every other year or so. Grease the important points, clean out the barrel
and the screens on my studio model Bluebird that I've had for years now. Th=
e
screens on the shaft had caught some trash from the reclaim clay, couple of
pebbles and a small blue plastic throwing rib. How did that get in there? I
usually check my slip bucket before hand but it musta gotten by me. However
the mill was in good shape, clean and ready to reassemble.
One question I have that someone may offer an opinion on is that the heavy
cast Aluminum pugmill barrel has become encrusted in areas that resemble
concrete that has been left dried on the bottom of a trowel or bucket. Not
too heavy but it takes a heavy amount of elbow grease with a bristle brush
to remove it. Underneath the Aluminum is almost black in color. I do not
want to use anything else that might scrape into the Aluminum itself
removing perhaps the "patina" from the surface. I have no idea what causes
this other than maybe calcium deposits from the hard well water reacting to
the Aluminum. Probably removing as much "scale" as I can will help the clay
through the mill barrel. Anyone care to take a stab at what causes this
buildup?

Dale Tex
"across the alley from the Alamo"
Helotes, Texas USA
www.daleneese.com


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Steve Mills on tue 3 aug 10


Dale, I think there was a thread along similar lines a while back. If I
rememeber correctly the consensus was you might be worried only if the Allo=
y
was low grade.

I don't think yours is.

Steve Mills



On 3 August 2010 14:10, Dale Neese wrote:

> I was doing a bit of pugmill maintenance yesterday that I usually perform
> every other year or so. Grease the important points, clean out the barrel
> and the screens on my studio model Bluebird that I've had for years now.
> The
> screens on the shaft had caught some trash from the reclaim clay, couple =
of
> pebbles and a small blue plastic throwing rib. How did that get in there?=
I
> usually check my slip bucket before hand but it musta gotten by me. Howev=
er
> the mill was in good shape, clean and ready to reassemble.
> One question I have that someone may offer an opinion on is that the heav=
y
> cast Aluminum pugmill barrel has become encrusted in areas that resemble
> concrete that has been left dried on the bottom of a trowel or bucket. No=
t
> too heavy but it takes a heavy amount of elbow grease with a bristle brus=
h
> to remove it. Underneath the Aluminum is almost black in color. I do not
> want to use anything else that might scrape into the Aluminum itself
> removing perhaps the "patina" from the surface. I have no idea what cause=
s
> this other than maybe calcium deposits from the hard well water reacting =
to
> the Aluminum. Probably removing as much "scale" as I can will help the cl=
ay
> through the mill barrel. Anyone care to take a stab at what causes this
> buildup?
>
> Dale Tex
> "across the alley from the Alamo"
> Helotes, Texas USA
> www.daleneese.com
>
>
> __________ Information from ESET Smart Security, version of virus signatu=
re
> database 5336 (20100803) __________
>
> The message was checked by ESET Smart Security.
>
> http://www.eset.com
>



--
Steve
Bath
UK
www.mudslinger.me.uk

Growing old is inevitable, growing up is optional!

Phoenix Rising Farm on tue 3 aug 10


Yes Steve, there was a discussion along those lines, and the aluminum
was blamed as being "of poor quality", IIRC.
However, the real culprit here is efflorescence. A reaction between the
clay and the aluminum, causing the leaching (or formation) and
subsequent hardening of salts (calcium chloride is a salt) in the outer
layer of the metal. That, mixed with the clay, is the crust. The black
that Dale mentions is oxidation, a byproduct, known when on ferrous
metals (iron-bearing metals) as "rust".
Soaking the (dried) clay, and cleaning the aluminum in a vinegar or
other acid based solution will usually remove the deposit and the black,
but trust me, it will return.
Personally, I don't worry about it. I have it in my pugger when in
prolonged contact with my white porcelain. The clay looks positively
nasty when it mixes in, dark, dingy gray. But at cone 10 it burns out
and the porcelain becomes white again. It does not affect the glazes I use.

Dale, do a test. Try firing some of that clay as a bowl or mug...a test
vessel. Glaze it as you normally would and fire it. Then see if it
made a difference. It might be something you can simply ignore.

Best,
Wayne Seidl



On 8/3/2010 12:08 PM, Steve Mills wrote:
> Dale, I think there was a thread along similar lines a while back. If I
> rememeber correctly the consensus was you might be worried only if the Al=
loy
> was low grade.
>
> I don't think yours is.
>
> Steve Mills
>
>
>
> On 3 August 2010 14:10, Dale Neese wrote:
>
>
>> SNIP for space
>> One question I have that someone may offer an opinion on is that the hea=
vy
>> cast Aluminum pugmill barrel has become encrusted in areas that resemble
>> concrete that has been left dried on the bottom of a trowel or bucket. N=
ot
>> too heavy but it takes a heavy amount of elbow grease with a bristle bru=
sh
>> to remove it. Underneath the Aluminum is almost black in color. I do not
>> want to use anything else that might scrape into the Aluminum itself
>> removing perhaps the "patina" from the surface. I have no idea what caus=
es
>> this other than maybe calcium deposits from the hard well water reacting=
to
>> the Aluminum. Probably removing as much "scale" as I can will help the c=
lay
>> through the mill barrel. Anyone care to take a stab at what causes this
>> buildup?
>>
>> Dale Tex
>> "across the alley from the Alamo"
>> Helotes, Texas USA
>> www.daleneese.com
>>
> www.mudslinger.me.uk
>
> Growing old is inevitable, growing up is optional!
>
>


--
Phoenix Rising Farm
393 on the Houlton Road
Waite, Maine 04492
A proud member of the
Washington County Food Alliance

Steve Mills on wed 4 aug 10


Ah yes Mon Ami, as the man said:" It all comes back to me now!".
I never had that problem with any alloy Pug I've owned (4), probably a
different alloy "recipe" here in the UK, but always with the steel ones (of
course). The "cure" for that was a warmed 2 part epoxy coating over the
inside of the barrel, worked a treat and lasted a looooooooong time. The
blades were Bronze so that part was OK.
Clay discolouration is not a problem with me as I'm a "Brown Pot" maker :-)

ATB

Steve Mills


On 4 August 2010 01:05, Phoenix Rising Farm wrote:

> Yes Steve, there was a discussion along those lines, and the aluminum wa=
s
> blamed as being "of poor quality", IIRC.
> However, the real culprit here is efflorescence. A reaction between the
> clay and the aluminum, causing the leaching (or formation) and subsequent
> hardening of salts (calcium chloride is a salt) in the outer layer of the
> metal. That, mixed with the clay, is the crust. The black that Dale
> mentions is oxidation, a byproduct, known when on ferrous metals
> (iron-bearing metals) as "rust".
> Soaking the (dried) clay, and cleaning the aluminum in a vinegar or other
> acid based solution will usually remove the deposit and the black, but tr=
ust
> me, it will return.
> Personally, I don't worry about it. I have it in my pugger when in
> prolonged contact with my white porcelain. The clay looks positively nas=
ty
> when it mixes in, dark, dingy gray. But at cone 10 it burns out and the
> porcelain becomes white again. It does not affect the glazes I use.
>
> Dale, do a test. Try firing some of that clay as a bowl or mug...a test
> vessel. Glaze it as you normally would and fire it. Then see if it made=
a
> difference. It might be something you can simply ignore.
>
> Best,
> Wayne Seidl
>
>
>
> On 8/3/2010 12:08 PM, Steve Mills wrote:
>
> Dale, I think there was a thread along similar lines a while back. If I
> rememeber correctly the consensus was you might be worried only if the Al=
loy
> was low grade.
>
> I don't think yours is.
>
> Steve Mills
>
>
>
> On 3 August 2010 14:10, Dale Neese om> wrote:
>
>
>
> SNIP for space
> One question I have that someone may offer an opinion on is that the heav=
y
> cast Aluminum pugmill barrel has become encrusted in areas that resemble
> concrete that has been left dried on the bottom of a trowel or bucket. No=
t
> too heavy but it takes a heavy amount of elbow grease with a bristle brus=
h
> to remove it. Underneath the Aluminum is almost black in color. I do not
> want to use anything else that might scrape into the Aluminum itself
> removing perhaps the "patina" from the surface. I have no idea what cause=
s
> this other than maybe calcium deposits from the hard well water reacting =
to
> the Aluminum. Probably removing as much "scale" as I can will help the cl=
ay
> through the mill barrel. Anyone care to take a stab at what causes this
> buildup?
>
> Dale Tex
> "across the alley from the Alamo"
> Helotes, Texas USAwww.daleneese.com
>
> www.mudslinger.me.uk
>
> Growing old is inevitable, growing up is optional!
>
>
>
>
>
> --
> Phoenix Rising Farm
> 393 on the Houlton Road
> Waite, Maine 04492
> A proud member of the
> Washington County Food Alliance
>
>


--
Steve
Bath
UK
www.mudslinger.me.uk

Growing old is inevitable, growing up is optional!