David Hendley on sun 18 jun 00
It does seem like it should be simple to attach an extruded
cylinder to a wheel and throw it. The problem is getting it
exactly plumb and centered; pretty much an impossibility,
and any 'throwing you do will simply magnify the eccentricities.
If you just want to be able to throw tall things without the
bother of pulling up a cylinder, your time would probably
be better spent practicing your throwing skills.
It really wasn't that long ago that sewer pipe was sometimes
handthrown (and salt glazed)!
For special situations however, throwing the top part of an extrusion
can be a good technique. I regularly extrude a hexagonal shape
and throw the top into a lip or bottle neck (a small vase made
using this technique can be seen in Diana's 'Extruded Ceramics' book).
For this technique to work, you have to let the extrusion set up
quite a while, so it will hold its shape, and then dip the top of
the extrusion in water several times, so it will be soft enough
to throw. Also, plan on the lip being wavy and uneven; plan
ahead by throwing a larger rim than you want and then trimming
the rim even.
The tallest extrusions I use for this are about 12-14" tall.
Of course it's impossible know from descriptions, but I wonder
if Joyce is using clay that is too soft to start with in her extruder.
The big plywood Bailey extruder dies are really pretty fragile.
I know that several people have broken them, and I think that
the company's admonition to use soft clay is a response to this
problem. I think that clay for extruding should be about the same
consistency as clay for throwing. Especially when working with
hollow shapes, you want your extrusions to reasonably hold their
shapes when extruded.
If you start with too-soft clay it will be impossible to work with
an extrusion and have it hold up.
--
David Hendley
Maydelle, Texas
hendley@tyler.net
http://www.farmpots.com/
----- Original Message -----
From: Joyce Lee
To:
Sent: Saturday, June 17, 2000 9:21 AM
Subject: extrusions
| I'd like to be able to attach tall, hollow cylindrical extrusions on my
| Shimpo and then throw them. Seems to me that should work well ... a
| cylinder being a cylinder, after all, and the form with which I usually
| start most of my pots. I HAVE been able to throw the shorter cylinders,
| but have to settle for a less than symmetrical shape..... which works
| well for some forms. Would any of you extruder users be willing to
| speculate as to the reasons I cannot do such a simple task? I may be
| leaving out something significant. I'm working solely on the smaller,
| hollow round form until I become familiar with the process. I sometimes
| attach a slab bottom before attaching the cylinder to the wheel;
| sometimes I don't ... same results. The clay is VERY compressed, of
| course. Seems simple. Not ...... so far. Sort of rips when I try
| throwing. Maybe this isn't worth fooling with ... I can and do throw
| cylinders daily .... the wish to throw an extrusion is just a passing
| fancy... but perhaps one of you knows what I'm talking about and could
| offer a suggestion??? Thank you as always for thinking of me...
|
| Joyce
| In the Mojave up since 3 a.m. and enjoying the early morning cool ...
Cindy Strnad on mon 19 jun 00
Thanks, David.
I was trying to use softer clay in my extruder after having read Joyce's
posts, and it wasn't really working. Now I feel better. I had gone
back to the ordinary clay, anyhow--you gotta do what you gotta do.
As an aside to your throwing a round rim onto a hexagonal extrusion, it's
also possible, and likely easier, to just throw the shoulder/rim separately
and then attach it. Of course, it will give a somewhat more "organic" look
to the pot, but I like that anyway.
Cindy Strnad
earthenv@gwtc.net
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
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