Anne on wed 12 nov 03
Dearest Clay People,
In one of my most impulsive clay tool shopping extravaganzas in 1998 I
purchased a pneumatic power extruder. I have never used it--frankly the
equipment and all the books I have and even the literature that came with
it all look pretty overwhelming.
I actually hooked it up and pushed one load of clay through it right after
I got it and the extrusion came out with pits and holes all over. I
thought immediately that I bought the cart before the horse. I was
thinking that having a pug mill to prepare the clay may just be the only
way to make this extruder work. It holds a lot of clay. I still don't have
a pug mill.
I am probably not allowed to say the brand name of this pneumatic power
extruder...but I will say that it has a 5" stainless steel barrel with a
9" expansion box. I also have many different dies that go with it. The
extruder is mounted on a universal stand assembly with a cutting/removal
stand that is sold for use with this extruder. It has a foot pedal to
operate it.
I have some friends who are experienced potters and they want to borrow it
to make planters. They do have a 4" pug mill. I have an air compressor
that is 5 horspower, 26 gallon, 125 max psi.
I want to help them out if I can. I would really like us to experience a
successful outcome...if at all possible. I don't want anyone to get hurt
and I would like to not break my extruder.
Any Advice is welcome. Kind of clay and preferred consistency? Air
pressure advice? Do's and Don'ts???
Thank you, I am looking forward to any help you might be able to give us.
Anne
claycat@mindspring.com
David Hendley on fri 14 nov 03
Anne, we know you have a Bailey extruder because it is the only brand
of pneumatic extruder being sold.
It does take practice and experience to learn how to use it.
You don't have to own a pugmill to prepare the clay for an extruder,
but the clay must be as well-prepared as clay for throwing on the
wheel. This can be done by hand wedging or kneading. The clay
should be a similar consistency to clay for throwing. In your
instructions, it probably says to use soft clay. Soft clay is easier on
the machine, but the finished extrusion will not hole up under
its own weight if the clay is too soft.
If you want to let your friends use your extruder, I don't think there
is a very high chance that they will damage it. The most fragile
component in this set-up is the die. Too much pressure with too-
stiff clay can bend or break a die.
You and your friends both need to realize, however, that it will
likely take some time for them to learn how to use the machine,
and there will likely be failures before they figure out the proper
techniques for producing what they want to make.
David Hendley
david@farmpots.com
http://www.farmpots.com
----- Original Message -----
> In one of my most impulsive clay tool shopping extravaganzas in 1998 I
> purchased a pneumatic power extruder. I have never used it--frankly the
> equipment and all the books I have and even the literature that came with
> it all look pretty overwhelming.
>
> I actually hooked it up and pushed one load of clay through it right after
> I got it and the extrusion came out with pits and holes all over. I
> thought immediately that I bought the cart before the horse. I was
> thinking that having a pug mill to prepare the clay may just be the only
> way to make this extruder work. It holds a lot of clay. I still don't have
> a pug mill.
>
> I am probably not allowed to say the brand name of this pneumatic power
> extruder...but I will say that it has a 5" stainless steel barrel with a
> 9" expansion box. I also have many different dies that go with it. The
> extruder is mounted on a universal stand assembly with a cutting/removal
> stand that is sold for use with this extruder. It has a foot pedal to
> operate it.
>
> I have some friends who are experienced potters and they want to borrow it
> to make planters. They do have a 4" pug mill. I have an air compressor
> that is 5 horspower, 26 gallon, 125 max psi.
>
> I want to help them out if I can. I would really like us to experience a
> successful outcome...if at all possible. I don't want anyone to get hurt
> and I would like to not break my extruder.
>
> Any Advice is welcome. Kind of clay and preferred consistency? Air
> pressure advice? Do's and Don'ts???
>
> Thank you, I am looking forward to any help you might be able to give us.
> Anne
Joyce Lee on fri 14 nov 03
I agree with all that David H. said........ I=20
ALWAYS agree with ALL that David H. says.
Never have I regretted doing so.
I do have the Bailey pneumatic extruder. I
do have to prepare my bagged clay to make
it softer for the extruder, which was a royal
pain, but now with the Peter Pugger, it's
all perfecto. I ran into problems immediately
when I didn't understand where my first 25
lbs had gone..... put it in .... nada.....=20
disappeared ..... couldn't find it anywhere.....
wasn't fixing to send another 25 lbs into
the Nether World............
(recall, please, what I've said about being
old and non-mechanically talented). Finally
talked to Bonnie, the CPA, and to Peter
in Florida, each of whom have the
same extruder model as mine... they explained=20
that it
was all compressed into that small square
area around the extrusion part. Yep, there
it was. Pretty smooth sailing ever since.
I did ruin my favorite die by using clay that
was too stiff and trying to force it through
the die..... warped all to heck. Drat. The
middle-sized square one ....=20
AND I had troubles with the air line being
shut off because the air compressor was
24 feet from the extruder.... wound
through shelves etc where occasionally
a pot or tool would crimp it. I didn't change
its position ..... #1 SP didn't want the compressor
too close to where I was working .... since
he recognizes that I not only don't KNOW
exactly how such tools work; I don't WANT to
know....... just want to know what moves
I need to make when.... and how to avoid
damaging any body, especially mine.=20
Anyway, I did
track the line,
found the obstructions, cleared them and now
the pneumatic works fine&dandy. I can follow
directions, which does help. I heartily recommend
the Bailey. If I can make it work, anybody can.
Joyce
In the Mojave
Klyf Brown on sun 16 nov 03
Annie,
I don't have a Bailey extruder, but I thought enough of them to build
mine largly copied after their earlier designs (mid 1970s) for a
freestanding portable pneumatic extruder.
Unlike other potters on list, my extruder seems to prefer a very plastic
clay stiffer than a throwing body. Some of my dies are backed up
with 1/4" pieces of steel to strenghten them and keep them from
buckling or breaking.
I also use grogged clay and that can be hard on the dies. I have
extruded over 1000 bowls with one die, however, and there is no
appreciable damage or widening of the extrusion.
The biggest safety problem is the loading area, especially if two or
more people are involved in the process. I couldn't tell exactly from
the pictures in the brochure how Bailey did their plumbing and valving
so mine is likely very different from theirs. But, there should be a valve
and peadle setting that will allow the plunger to slide down freely. This
will probably be an "all valves open" thing. If you can do this, it is the
way to start an extrusion. Load the barrel with at least 1/2" open
headspace. open the valves and slide the plunger into the gap, then
procede with your extrusion. Failure to follow this procedure can lead
to pinching off of fingers, or at best, bending or breaking of the
plunger head. Also, in loading and servicing, be sure to position valves
open to avoid someone accidently stepping on the pedal and the ram
breaking or causing bodily harm. The best policy is to have the
machine equipped with a quick disconnect on the air feed, and
disconnect the extruder whenever working on it or loading it. Have all
valves closed while working on it.
It is also a good thing to not have the plunger fit the barrel to tightly. It
takes more clean up because this will leave a thin layer of clay on the
barell (I just let it dry out, then knock it off) but it allows air to escape
rather than be trapped in the clay. This leads to fewer blowouts in the
extrusion. It seems that no matter what I do, there are always a few
air blowouts, I just patch them up. No matter how good you wedge
or pug, you have to put in multiple pugs to load it, and that can induce
an air pocket.
Another point, when not in use always leave the machine with the
plunger fully retracted. Failure to do so exposes the ram to rust and
dirt and that can tear up the seals and ruin the ram. Also, always leave
it with all valves closed to prevent stuff from getting in the lines and
ram. If the Bailey is not equipped with an air dryer, install one before
use. If water from the lines (all compressors will have condensation in
the tank and lines) gets into the ram it will rust and ruin the ram. A
cheap replacement ram is $350, they retail at about twice that price.
These are fantastic machines and well worth learning to use. I much
prefer it to a wheel nowadays. Much greater latitude in form design
and much easier to make a piece for a sufferer of back problems. It
does, however, take me much longer to make a pot than with a wheel
as there is a lot of handbuilding involved in turning an extrusion into a
pot, and many times, as much as 5 or 6 extruded pieces to make a
pot ((foot, base, body, lip, handle, lid, etc). Or maybe I have slowed
down a lot over the years.
Klyf in New Mexico
Snip
I have some friends who are experienced potters and they want to
borrow it
to make planters. They do have a 4" pug mill. I have an air
compressor
that is 5 horspower, 26 gallon, 125 max psi.
I want to help them out if I can. I would really like us to experience a
successful outcome...if at all possible. I don't want anyone to get hurt
and I would like to not break my extruder.
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