mark Cortright on wed 16 jan 08
David you are right about the time spent modifying that Scott Creek unit I could have made two.
The thing was back in high school in 69 when I learned to throw then in collage ceramics in the
early 70s I had no tools or skills with a wielder.A few buddies chiped in and bought one from Al
Johnson if I recall correctly. A couple of friend's made theirs but they were junk in the long run. Al
had I thought the best one around back them (74??). All commercial units are a compromise I feel.
I do not use an expansion box or make hollow extrusions so a shorter barrel works ok for me. It is
a pain to reload but porcelain tends to dry out fast so larger for us is not better.We wrap the barrel
in plastic bag but it still drys out when the heat is on. I got the Brent for a song new and like
having two handle shapes ready to squirt. After building over 10 kilns and lots of other stuff the
extruder building seems low priority . Do it when you have lots of time -now as my time seems
more valuable when one is older I seem to spend non ceramic time on my other 10'ooo intrests-
comercial diving-underwater photos-tuna fishing- see my trouble is I am passionate about many
intrests and life is so short.
Clay has been my life for over 30 years now. . I know you can relate from a story you either told
me at Mendo workshop or I read. Its about your wood supply now coming on pallets vs hand
loading -you pay a little extra for the pallets now cuase its easier.
I like your extruder but it looks low-do you have to bend over to get the extrusions? Mark
Cortright
mark Cortright on wed 16 jan 08
My studio has been producing a gazillion mugs for past 30 plus years as well as many handled
forms and we use our extruder for just about all the handles. I have an assistant that puts on
handles just about daily. This is the testing-real heavy use. I bought a Scott Creek Extruder way
back in the early days When Scott just starting making them. Its a 4 inch steel tube. It had an
almuinum cap with threaded thumb screws. This setup wore out soon-the holes in the steel 1/4
tube wore down so I bought a brent cap and wielded on the ears so it twists on quikly. This has
worked well-I had to modify the handle as well but have noticed the new Scott Creeks have a
better handle now. We wore the steel plunger down so to much clay was blowing by it and last
year I wielded another on-Scott creek said they have never seen one worn out.
The past year I got a Brent and wall mounted it-For the past year we now have two extruders and
both have there own merits-The draw back with the Brent is it does not extrude all the clay from
the barrel. it leaves some at bottom. It slips now and then on the pull down and is a bit larger on
the wall. the pros are it has the best cap system and is built to take abuse. The Scott creek is a bit
smoother on the pull dowm and is smaller on the wall. The cap system I know knowing about
them as they have a new one out now.
We work with porcelain and the rusting steel barrels never show up in the fired product-I do not
think aluminum is a good extruder material stainless yes but its really not needed.. Brent 9 stars
for me scott Creek 7 stars.. Mark Cortright
liscomhillpottery.com
David Hendley on wed 16 jan 08
Gee Mark, considering all the work you have done to
repair and modify your extruders you could have easily
built your own extruder.
You could have a machine that absolutely would not wear
out, for a fraction of the cost of buying 2 commercially
available extruders.
The extruder is the one piece of pottery equipment that
is easy for the potter to build, with a resulting machine that
works as good or better than a commercial one. I have built
wheels, pug mills, and lots of smaller machines/tools. The
extruder is the one thing I always encourage potters to build.
All the available extruders have drawbacks. Mark is right, the
little thumb screws in the early Scott Creeks were not hefty
enough. The new 'pin through hole' system is passable, but not
the best, as it can be a pain to find the hole as you are trying to
install the cap. And aluminum will wear down under really
heavy use. I also think moving the pivot point of the handle
down into the next cutout as you extrude is clumsy.
The Brent extruder has a barrel that is too short and, as Mark
said, will not allow you to use all the clay in the barrel. I do not
like the 'twist-on' die holder because it does not easily
accommodate different thicknesses of dies. Also, the 'shelf' that
holds the die in the die cap is too wide - it does not allow you
to take advantage of the full diameter of the barrel.
The plunger plates on both these extruders is too small - they
allow too much clay to stick to the barrel or ooze up around the
plate. A really good extruder would have a machined plate that
exactly fit the barrel (pipe is not exactly round on the inside
either, so it would have to be machined).
So what do I use? The extruder I built in 1975. I certainly don't
make gazillions of mugs, but it shows no signs of wear after
30 years of constant use. It is built from steel pipe. The die
holder is a piece of larger steel pipe, with 3 tapped holes (actually
drilled holes, with nuts welded over the holes, as I had welding
equipment but didn't have a tap in those days). It is easy to
remove the die holder and change dies without removing clay
from the barrel. The barrel is longer than the Scott Creek and
Brent, for less re-loading.
The plunger plate is more like a piston - it was built from a 3 or
4 inch length of smaller pipe that fits inside the barrel, with a
cover on the bottom. It is attached with a bar going through
the plunger arm into the piston. It swings, or pivots, like a
piston in a engine. Take a look at the 'studio tour' page of my
website for some pictures:
http://www.farmpots.com/studio.htm
There is a picture of my expansion box, for extruding larger
things, as well as a picture of my small handle dies on my
'writings and publications' page:
http://www.farmpots.com/pub.htm
When I have to recommend a commercial extruder to
people who don't want to build their own, I usually go for
the Scott Creek. Of course, Bailey would be the best choice for
someone wanting to do lots of large extrusions.
Dies are a whole 'nother story - I rate the dies that come with
both Scott Creek and Brent as 'poor'. The 'spider' system for
2-part dies is not a good one. It is much better to use U-bolts,
or something similar, to make dies that have the internal and
external part permanently and precisely joined together.
David Hendley
Maydelle, Texas
david(at)farmpots(dot)com
http://www.farmpots.com
| |
|
