Craig Martell on tue 21 oct 97
Hi:
I just fired my hardbrick Salt Kiln after coating with ITC 100 and this is
to inform those interested of the results.
This is a kiln that has been salted about 4 times prior to coating with ITC.
I chipped off slag and debris and wire brushed and vacuumed the kiln prior
to dampening and spraying on the ITC. There was absolutely no flaking or
peeling and I only lost one piece out of the load and this was due to
cracking, not the ITC.
I also put some softbrick tests in the kiln. I coated two k-23 samples and
two k-26 samples. All four emerged unharmed by salt fumes. One of the k-26
bricks had some 2300 degree kaowool veneered to it and the kaowool came
through very well too. I placed the kaowool veneered k-26 on the bagwall,
where all hell breaks loose so this was an extreme test. Also, the other
k-26 and the k-23s were exposed on 5 sides, which also is extreme exposure.
Usually, wall brick has only one hot face. These tests were placed on the
edge of the shelves, hanging over the firebox. They were exposed to a lot
of heat and salt vapor. I realize that one salting will not tell the whole
story, but the results are more than promising. If we can confidently
construct our kilns with insulating firebrick instead of hards, the fuel
savings will be tremendous, and even better with salt-soda kilns built with
fiber z-block modules coated with ITC.
Given the results of this firing, I have to say that any doubts that I had
about ITC 100 are in the toilet. I think it's a good product. Expensive,
but it works.
On another note, I tried some alumina-carbide shelves in the firing and they
are MORE salt resistant than silicon carbide!! There was no buildup of salt
on the shelves whatsoever. I didn't have to clean them at all after the
firing. The downside of these shelves is their weight. A 13x26x5/8
alumina-carbide weighs a whopping 29lbs. My 12x24x1/2 silicon carbides
weigh 16lbs and the 12x24x5/16 crystars and advancers weigh about 9lbs.
But, I got 10 of these alumina- carbides for $10 each, used, and they will
probably outlive me!!
don't work too hard, Craig Martell-Oregon
Joseph Bennion on wed 22 oct 97
Craig and all ,
You are right about with holding final judgment on your new
refractory products till after many firings. Also, how much salt are
you using? I put cheap high alumina shelves in my kiln and loved how
they performed for the first dozen or so firings and then horrified as
they slowly came apart and self glazed themselves. ITC may be fine but
you won't know for another year or so.
Regards...Joe the Potter
===
Joseph Bennion "Never quit your day job."
PO Box 186 Jerry Garcia
Spring City, Utah 84662
801-462-2708
joe.the.potter@rocketmail.com
_____________________________________________________________________
Sent by RocketMail. Get your free e-mail at http://www.rocketmail.com
Craig Martell on thu 23 oct 97
At 10:33 AM 10/22/97 EDT, Joe Bennion wrote:
>----------------------------Original message----------------------------
>Also, how much salt are you using? I put cheap high alumina shelves in my
kiln >and loved how they performed for the first dozen or so firings and
then >horrified as they slowly came apart and self glazed themselves.
Hi Joe:
The kiln is 54 cubic ft. total space, and I use between 15-20 lbs of salt
per firing. In the firing with the ITC and soft brick tests, I used 16 lbs.
and all the pots were pretty well glazed and showed hard edge leaching from
salt attack. The soft brick coated with ITC was totally unharmed according
to a visual check. I've seen what salt does to IFBs that are unprotected.
I've also used high alumina shelves in salt, and you are absolutely right,
they don't cut the mustard. From the very first firing, they showed signs
of deterioration, even when coated with 75% alumina-25% kaolin shelf wash.
But, alumina carbidies are not the same as high alumina shelves. They are
denser, have more tensile strength, and WILL withstand greater heat and
sodium vapor. They are not cheap either, if you can find them and puchase
new ones. The ones I have are used, have been fired to cone 12 more times
than I care to think about(not by me) and they are still in good shape.
There was absolutely no sign of salt attack on these shelves. I had to
scrape salt residue off the silicon carbides I used in the firing, but not
the alumina carbides.
Regards, Craig Martell-Oregon
| |
|
