You can use a garage-variety hand grinder with a cutting wheel GENTLY
for the glaze on shelves also. If it's small enough, a dremmel took
might work also.
Brookings Middle School
From: Marvin Bartel [mailto:email@example.com]
Sent: Saturday, March 17, 2007 9:15 AM
To: TeacherArtExchange Discussion Group
Subject: Re: [teacherartexchange] glaze question and clay looms
>1. I had a bunch of glaze drip off of a project and stick to the kiln
>shelf (I did use stilts). I tried chiseling it off and I cannot get it
>all off. I looked at some posts online and they suggested using a
>power chisel. I do not have access to one. Does anyone have any other
>ideas to save the kiln shelf?
>2. Also, we've been making clay looms. Most of them have turned out
>great, but we had a little problem with some of them breaking, because
>they are thin, flat pieces. Also, the holes sometimes got covered in
>while glazing (we tried poking through them with pins before firing,
>but some of the glaze still ran into it). Has anyone made clay looms
>before and have any suggestions?
1. _ _ it happens. To remove glaze from shelves, I use a standard
freshly sharpened stone chisel with a steel mallet (hammer). The chisel
is re-sharpened with an electric grinder (dipping in water very
frequently to prevent over heating that removes the hardness). A belt
sander is also good for sharpening tools with less overheating than a
Set the shelf vertical on the floor so it is learning against the wall
nearly vertical using a sponge behind it at the top edge (to cushion it
a bit). Hold the chisel as vertical as possible so you do not break the
shelf when you whack it. Keep whacking at the glaze globs harder and
harder until the glaze breaks off. Turn the shelf as needed to hit the
glaze from other directions. This may take a divot out of the shelf,
but you can fill the divots with thick kiln wash. A hand held high
speed electric grinder also works. Anyway you do it, it is a labor
intensive job. ALWAYS wear eye protection.
If you cannot or choose not to remove the glaze. Cover it with heavy
kiln wash mixed with some silica sand and fire it with the glaze still
on the shelf. You can try again to chip it off after another firing.
To prevent the problem next time, use more kiln wash on the shelves and
less glaze on the pots. Also, be sure the kiln is not firing hotter
than it would need to.
2. I was wondering why the clay looms would be glazed? In the Dremel
tools section in the hardware store or building supply store they sell
small diamond wheel points. These diamond drills can cut through glaze,
but it may be better in the future make the pieces without glaze on this
area of the piece. This page shows the diamond wheel points.
If I want to glaze an area with holes (like a salt shaker), I use wax
resist to fill holes prior glazing. If holes are too large for wax, I
fill them with wet paper wads prior to glazing. I poke these out and
toss them before firing.