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repairing the floor of my kiln ... itc ... thanks!

updated thu 25 jul 02

 

Paulette Carr on mon 22 jul 02


I want to further thank Bill, Lori and Marj for your suggestions.

Yes, I will definitely use 6 posts instead of 4, though I really don't want a
gap between half shelves. I am firing large tiles, over the shelves, on the
coils/rods that Vince suggested. I think that the heat from the bottom is
not stopped at the bottom shelf and does not cause a problem in the kiln. I
have three temperature zones, and the kiln fires fairly evenly. I think that
Marj is probably right about the cookie idea creating hot spots, but wouldn't
I also get hot spots where small pieces of kiln shelf are suspended over the
elements (several mm away) as Bill suggested? The coils are arranged in
roughly 3 concentric circles (allowing for connection of one circle to the
next), where the outer circle is right where you would put your kiln posts.
Using firebrick as posts, especially as larger posts might work, but they
would also span the elements and cover larger sections ... I don't know if
that is a problem (bigger or smaller) if the post is fire brick rather than a
small kiln post. Maybe I could locate them randomly in the areas where there
are no elements, along with the regular posts, and these bricks would take
some of the weight off those 6 points. Bill, what is your experience with
placing something like a small piece of kiln shelf directly on the floor
where it covers part of the element?
What if I coated these pieces with ITC 100? I will definitely coat the posts
with ITC.

I wouldn't mind making a kaowool patch for each post, but, Lori, what will
happen to the kaowool and or the element if this sits directly above it? My
kiln furniture is refractory, but the soft firebrick out of which the kiln
was built seems to be the problem.

So for right now, I am pursuing the ITC idea: What I really want to do is to
stabilize and isolate the soft brick from further damage, and I think that
ITC coating and patching may be the way to go.

Just curious if others have placed anything over small sections of the
elements on the floor of their kilns ... any observations, or problems?

Thanks, again! My best,
Paulette Carr
St. Louis

Arnold Howard on tue 23 jul 02


I have never placed an obstruction over a floor element. However,
according to element theory, this would cause an element section to
get too hot, which would destroy the element.

Using broken shelf pieces to support your posts, as someone
suggested, sounds like a great idea. But I would not recommend
placing them over an element.

Arnold Howard
Paragon

>
> Just curious if others have placed anything over small sections
> of the
> elements on the floor of their kilns ... any observations, or
> problems?
>
> Thanks, again! My best,
> Paulette Carr
> St. Louis


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Lorraine Pierce on tue 23 jul 02


Hi Paulette...I have pulled out my Axner catalogue and looked at the floor
configurations of the Axner electric kiln with an element in the floor and
the Cone Art kiln and am amazed at the difference. The Axner appears to
allow adequate space to position posts without interferring with the
elements...the Cone Art kiln appears to allow very little space between the
wall and the outside floor element. Are special posts supplied that straddle
the floor element? Now I understand your dilema.

I have also checked out the Bailey catalogue. Their 'element-in-the-base'
seems similar to the Cone Art kiln, and I am wondering if perhaps the posts
are positioned between the outer two floor elements rather than the element
and the wall? What does your manual suggest? Sorry I was not of more
help...I do know the ITC worked for me in my Skutt kiln ( no floor element),
as well as the refractory blanket. It had not occured to me that you could
place posts on top of your floor elements. I was taught to keep furniture
and ware one inch from the element. and to never use more than three posts
per shelf ( to prevent rocking). Also that the first shelf was to be no
closer than two inches from the floor.

Pauline! This is it! I have just found a picture of a rectangular electric
kiln in an English book, The Electric Kiln by Harry Frazier, that should
interest you. The floor has eight closely spaced elements in it.The first
shelf is supported on what could be pieces of shelving that BUTT up to the
edge of the kiln side wall, and the first shelf spans the imbedded elements
perhaps an inch above them resting and supported by this ledge. Pictured is
a space between the shelf and the side wall of about a half inch. The
remaining shelves and ware are stacked conventionally, posted with the usual
English stilts. Again a mason can cut a kiln shelf for you to make these
ledge pieces to place the first shelf above the elements ; Perhaps the
pieces would also span the problem areas of broken brick. I hope I am
clear and that this works for you. If you cannot find the book, remember
Interlibrary Loan! Lori Pierce in new Port Richey Fl.

william schran on wed 24 jul 02


Paulette asks about placing part of a broken kiln shelf over elements
in the floor of her kiln.

A definite NO. The shelf hanging over the element will cause the
radiant heat to radiate back to the element, causing it to be hotter
and consequently deteriorate faster.
I'd go ahead with the idea of coating with ITC 100, set your bottom
posts and leave them in place all the time.

An aside (but related) - I had 2 inch tall posts supporting my bottom
shelf which had the shelf about the same level as the bottom element.
Also use a Bailey vent system (downdraft, small hole in wall near
bottom, top spy hole plug out all the time). Found bottom always a
bit cooler. Recently raised the bottom shelf above level of bottom
element (I think 4 inch posts) and firings are now right on, top to
bottom (checked with witness cones at all 3 levels).
Bill