John Tiemann on fri 16 jul 99
Sorry if this message went through the list already, but I haven't seen it =
show
up on the list since I sent it the first time... so all apologies if this
message comes up twice.
I have recently finished my first year of teaching ceramics at a Visual and
Performing Arts High School in St. Louis, Missouri. Among the kilns I have,=
I
am firing two electric Skutt kilns that have been around for some time. I =
am
not sure when (or if) the teacher(s) before me have replaced the coils =
within
the kiln, and I am asking for any suggestions on....
1. What are some signs of the coils going bad or in need of being replaced?
2. I have found packages in the studio with NEW coils in them. They are =
labeled
=22top, middle, bottom=22. Can anyone refer me to any handouts, books, etc.=
that
would help guide me through the process of replacing the coils? I have =
tried
looking for the manuals and contacting Skutt with little or no success. Any
tips would be helpful at this point. I don't really have the funds to have
someone come in and do it for me.....so I'd like to learn and do it myself.
3. I have also heard that after the coils have been replaced, the kiln =
should be
fired empty once to =5E4 so some sort of coating can form on the coils???? =
Anyone
with comments or an explanation to this?
Thank you in advance for ANY help you can offer to me. I'd like to take =
care of
this before school starts again in the fall and realize when it's too late =
that
the coils are shot=21=21 Hope you hear from you soon=21=21
John Tiemann
St. Louis, MO
wschran@erols.com on sun 18 jul 99
<000d01becf32$3ec27b80$1c034cc-@jtiemann.dtd1.slps.k12.mo.us> wrote:
original article:http://www.egroups.com/group/clayart/?start=48016
> ----------------------------Original message-------------------------
---
> Sorry if this message went through the list already, but I haven't
seen it show
> up on the list since I sent it the first time... so all apologies if
this
> message comes up twice.
>
> I have recently finished my first year of teaching ceramics at a
Visual and
> Performing Arts High School in St. Louis, Missouri. Among the kilns
I have, I
> am firing two electric Skutt kilns that have been around for some
time. I am
> not sure when (or if) the teacher(s) before me have replaced the
coils within
> the kiln, and I am asking for any suggestions on....
>
> 1. What are some signs of the coils going bad or in need of being
replaced?
>
> 2. I have found packages in the studio with NEW coils in them. They
are labeled
> "top, middle, bottom". Can anyone refer me to any handouts, books,
etc. that
> would help guide me through the process of replacing the coils? I
have tried
> looking for the manuals and contacting Skutt with little or no
success. Any
> tips would be helpful at this point. I don't really have the funds
to have
> someone come in and do it for me.....so I'd like to learn and do it
myself.
>
> 3. I have also heard that after the coils have been replaced, the
kiln should be
> fired empty once to ^4 so some sort of coating can form on the
coils???? Anyone
> with comments or an explanation to this?
>
> Thank you in advance for ANY help you can offer to me. I'd like to
take care of
> this before school starts again in the fall and realize when it's too
late that
> the coils are shot!! Hope you hear from you soon!!
>
> John Tiemann
> St. Louis, MO
>
>John - Certainly one way to tell if the kiln elements are going bad is
to test fire. You can leave the kiln empty, or load it up, and do a
regular cycle firing, and see how long it takes. The surest way is to
do a ohm resistance test. Ask if some one in the school has an ohm
meter, and knows how to use it, and test the new elements resistance
(attach one clip to one end of the element and the other clip to the
other end). You will need to find out from Skutt what the ohm rating on
the elements should be. If the elements in the kiln are more than 10%
off, you should replace them.
Replacing the elements is fairly easy, but scary the first time. Be
sure and unplug/turn off circuit breaker. You will need to unscrew and
remove the panel/switch box from the kiln. Take a minute and look at
how the wires from the switches are connected to the elements. See if
they are twisted around a bolt & nut combination or are attached by a
compression coupling (a short hollow piece of metal in which the wire
and element are inserted and crimped). Loosen the nut or cut the wire
(if compression fitting) close to the fitting (you will need new
compression couplings). ONLY DO ONE ELEMENT AT A TIME! Slowly pull,
from inside the kiln, the element out. Needle nose pliers work well for
this. The element may be held in place by element pins, which you need
to pull out. The element is going to be very brittle and break up
easily. You can save the pieces to stilt work or stick in clay for low
fire scupture :). The element may be already stretched to its proper
lenght or may need to be stretched. Use a piece of string to measure
the groove where the old element came out of. If the new element is
about the same length as that measurement, your set. Otherwise you'll
need to carefully stretch out the element very evenly to the proper
length. Insert element back in groove and the ends through the openings
in the kiln wall to be reconnected. Pin elements inside the kiln with
new element pins (will have come with elements if needed, well
usually). Cut off excess pigtail(twisted ends of elements) to length
like other ones you haven't removed yet. Re-connect wires and move on
to next set of elements.
The elemnets are made of alumina and chromium. When heated the elements
form a protective coating of alumina on the surface. This is what that
first heating does. Burning organic compounds can destory this
coating, so don't try to do any reduction fire things in the kiln.I
know this is a short explanation, be happy to answer more specific
questions.
I teach at a local community college where our supply budget for the
whole art department is about $1000 for the whole year. I've had to
taech myself hoe to repair ALL the equipment in the ceramics studio AND
other studios too! I know what you're going through.
Bill Schran
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