CLAY PREPARATION
Any type of clay is usable for extruding, but property pugged and de-aired clay works the best. Coarse clay with a high percentage of grog, if de-aired, works fine. Clay that is too soft and poorly wedged may tear and have air bubbles in it as it is extruded. Trying to extrude clay that is too hard through a small hole will put stress on the extruder and will cause damage. Make sure you use soft clay.
LOADING AND USING YOUR NEW EXTRUDER
- Remove the handle and plunger from the barrel
- Remove the pins holding the cap on the bottom of the barrel
- Put a die in the cap and replace the cap and pins in the barrel
- Form a fat coil of soft clay, to fit the size of the barrel
- Drop the coil in the top of the barrel
- Place the handle pin into the top notch of the backbar bracket
- Gently pull the handle down. When the handle is depressed to its lowest point, remove the handle pin, ratchet down the backbar one pin space. and gently pull the handle down. Repeat.
- When using the inner die holder, do not put the handle in the last notch on the backbar, this will cause the inner die holder to break.
TIP
When making extrusions, use firm, slow pressure to pull the handle down. If you have to use the full force of your adult weight on the handle, the clay is too stiff or the size of the opening in the die is too email. If the clay is too stiff, remove it from the barrel and use softer clay. If the size of the opening in the die is too small it will cause significant back pressure, to alleviate this drill additional relief holes in the die.
MAKING HOLLOW EXTRUSIONS
We use a unique, 2-part system for making hollow extrusions. Scott Creek Pottery's extruder uses a floating inner die holder which makes it possible to easily change the thickness of the extrusion‘s wall as well as the inner and outer shapes. Our unique floating die system allows you to combine dies that are different in size and shape. For example, you could use a square outer die and a circular inner die to form an extrusion that has a square exterior and a round interior gap.
The challenge in using the floating dies is keeping the gap between the inner and outer die fixed in place until the clay is forced through the inner die. A simple solution is to gently load the clay into the barrel, and slowly depress the plunger. Once the clay is compressed around the inner die holder it will not move until you want to switch dies. Another solution is to load your die into the cap and use chunks of clay to hold your set of dies in place while you install the die and cap and then load the extruder barrel.
DIES
All dies that are sold for the extruder are made of 1/8" aluminum. These will not bend but are easy to cut with a simple coping saw. Simply draw your design on to the die , drill a pilot hole in the center of the design. Cut out with the coping saw. Finish the shape with a file, and you have a die that will last indefinitely.
TIP
You may out several small shapes from one die and block out the ones you don't want to use with a stiff piece of plastic or metal.
SLAB MAKING WITH AN EXTRUDER
SC027 for 4" Wall Mount Extruder (requires inner die holder)
SC028 for 5" Wall Mount Extruder (requires inner die holder)
Using the hollow round die, extrude semi-soft clay into a pipe form approximately 36” long. Place the extrusion horizontally on brown craft paper and cut one side in a straight line. Open form cutting down the long way to produce a 17" slab, 36” long. Place paper on the surface and extrude another, using the paper as a separator.
We think extruded slabs are superior to rolled ones, perhaps because particles are aligned in a different way. In any event, they seem more stable.
CLEANING YOUR EXTRUDER
Here's the recommended way to clean the aluminum extruder:
- Let the clay dry out in the barrel
- Remove the barrel from the backbar and knock out the dry clay.
- Drop the barrel into a 5 gallon bucket of water. Wait 5-10 minutes until it soaks clean.'
- Use a sponge to scrub any excess clay left inside the barrel.
