WHC228@AOL.COM on tue 3 dec 02
Mixing slip is one part of the process. The second is to keep the
slip in suspension without bubbles.
The second part is the most important. Two things need to happen.
1. The slip has to be bubble free, or there are defects in the pots, and
glaze.
2. The slip must be kept in motion so that you get FALSE deflocculation
because of it being under "shear." Keeping the shear and allowing the shear
does a lot of nice things when you are casting. A. It allows you to have more
liquid slip without as much water, and deflocculants. It also does nice
things because you get a better gel rate when the slip is used. When it is
used it goes from being more liquid to a gelled state that pours out of the
mold better. This gives a cast that isn't as likely to have erosion marks, or
curtianing.
This type of mixing is Blunging. The arms in the tank are long, and have
paddles on their ends. They usually turn no faster than 33RPM.
That allows the slip to roll in the tank without sucking in any air.
Making a mixer that does this task is a little more complex than the kind of
mixer that just beats the material, and water into submission.
It will take a motor with a gear reducer, some belts and pulleys, some pillow
blocks for bearings, and some kind of framework over the tank to keep it all
in place.
It should run all of the time.
Good mixing.
Bill Campbell
RPeckham@COOKSONELECTRONICS.COM on tue 3 dec 02
I needed to mix up some urethane resin in the lab the other day, and it
was thicker than others that I had used. I decided I needed a mixer, and
didn't have time to go looking for one.
In the drawer with the hex keys, there was a 1/8" "T" handle hex key. I
stuck that in my drill, and voila a quick mixer.
I would guess that you can make the end out of just about anything. Will
work better if it is balanced. The only think you will suffer is a loss
of efficiency. I have seen advertisements for a mixer with a spring
attached to the end. Stainless springs are readily available. Even just
attaching a bar at the end would work.
One caution to the bar at the end mixer, make sure your slip bucket is up
to the task. I used one that I had made, and punched a hole in the side
of the bucket right near the bottom. Pretty messy.
Good argument for a disc shaped mixer.
Maybe just a flat disk with some holes drilled in it at an angle, in a
radial pattern around the center, that way when it spun it would pull
material up through the holes.
Randy Peckham
New studio without forced hot air heating is wonderful. Nothing has
cracked yet, and I haven't covered anything with plastic. Unbelievable.
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