claybair on fri 20 jun 03
Well..... I have now had my first glaze firing disaster.
I was in a hurry to load & fire the kiln (L & L JD230).
The last piece placed was a vase about 1" from the kiln wall.
It was one of the last pieces glazed. It was a thin walled piece
the interior glaze too thick. Looking at this retrospectively
the bisque got saturated and the glaze on the outside didn't adhere.
I ignored the tell tale slight cracking in the glaze. I saw it and ignored
it...
Arghhh!
Of course it was on a top shelf, it didn't just run off the pot ... it flew!
The glaze on the outside just ran off the middle of the pot and dripped
down onto 3 shelves. As if that wasn't bad enough it also jumped
onto the kiln bricks then jumped 2 inches over to the right to nicely glaze
the thermocouple, more kiln bricks and kiln floor!
To add insult to injury for some stupid reason I soaked this firing longer
than
I usually do which just added to the mess.
My question is what would be the best way to remove glaze from the
thermocouple?
It is a heavy duty one. It has been suggested to me to try carefully grind
it off using my Dremel.
I do have a diamond bit which has nicely removed the glaze from the shelves
and element holders. Any other suggestions?
The soft brick on the wall now has a few gouges no deeper than 1/2" and no
wider than 1".
Do I have to repair them? I figure I will repair any gouges on the kiln
floor but hopefully the kiln wash there will protect the brick.
Next question......If some glaze is on the element what should I do?
Thanks in advance for any suggestions.
On the bright side only 3 pieces were ruined & most everything else came out
great.
I should never load kilns when exhausted... seems I said this a few years
ago!!!
Was dumb and now dummerer!
Gayle Bair
Bainbridge Island, WA
http://claybair.com
Tony Olsen on sat 21 jun 03
Gayle,=20
If the glaze on the TC is not too thick, why not just leave it on there? =
If it is thick and may drip, make a small dish to set under it for a =
few firings. The TC will work fine as is. Trying to remove it sounds =
like it may do more harm than good. =20
However, if I were to try it, I'd take a small hammer and place the TC =
on a very hard surface e.g.: my table saw top, such that the part I want =
to break, (the glaze) is directly on the surface and very lightly tap =
the glaze with the hammer. The TC wires are more flexible than the =
glaze and the glaze should crumble off. You do run the risk of breaking =
the TC if you try to remove the glaze. I think I would just try to fire =
again a couple of times with a drip pan under it.
Best of luck!
Tony Olsen
http://tonyolsen.com/up/
Roger Korn on sat 21 jun 03
I'd suggest using a diamong burr on the Dremel tool. Working carefully,
you should be able to clean it up. Test against a known-good
thermocouple, because glaze traces my introduce an error when they
re-melt. Some of the more strongly polar molecules could introduce an
electrolytic voltage on the order of tens of millivolts - right on the
order of magnitudeof the thermal EMFs that the thermocouple produces.
Worst case, at least in the case of a Type K thermocouple, you can grind
off the welded junction completely and weld a new junction using an
oxy-acetylene torch with a 000 tip. This always works well form me, but
I haven't tried it on anything except a Type K thermocouple.
Hope this helps,
Roger
claybair wrote:
>Well..... I have now had my first glaze firing disaster.
>
>I was in a hurry to load & fire the kiln (L & L JD230).
>The last piece placed was a vase about 1" from the kiln wall.
>It was one of the last pieces glazed. It was a thin walled piece
>the interior glaze too thick. Looking at this retrospectively
>the bisque got saturated and the glaze on the outside didn't adhere.
>I ignored the tell tale slight cracking in the glaze. I saw it and ignored
>it...
>Arghhh!
>
>Of course it was on a top shelf, it didn't just run off the pot ... it flew!
>The glaze on the outside just ran off the middle of the pot and dripped
>down onto 3 shelves. As if that wasn't bad enough it also jumped
>onto the kiln bricks then jumped 2 inches over to the right to nicely glaze
>the thermocouple, more kiln bricks and kiln floor!
>
>To add insult to injury for some stupid reason I soaked this firing longer
>than
>I usually do which just added to the mess.
>
>My question is what would be the best way to remove glaze from the
>thermocouple?
>It is a heavy duty one. It has been suggested to me to try carefully grind
>it off using my Dremel.
>I do have a diamond bit which has nicely removed the glaze from the shelves
>and element holders. Any other suggestions?
>
>The soft brick on the wall now has a few gouges no deeper than 1/2" and no
>wider than 1".
>Do I have to repair them? I figure I will repair any gouges on the kiln
>floor but hopefully the kiln wash there will protect the brick.
>
>Next question......If some glaze is on the element what should I do?
>
>Thanks in advance for any suggestions.
>
>On the bright side only 3 pieces were ruined & most everything else came out
>great.
>
>I should never load kilns when exhausted... seems I said this a few years
>ago!!!
>Was dumb and now dummerer!
>
>Gayle Bair
>Bainbridge Island, WA
>http://claybair.com
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
>
>
--
Roger Korn
McKay Creek Ceramics
In AZ: PO Box 463
4215 Culpepper Ranch Rd
Rimrock, AZ 86335
928-567-5699 <-
In OR: PO Box 436
31330 NW Pacific Ave.
North Plains, OR 97133
503-647-5464
E.G. Yarnetsky on sun 22 jun 03
It's been said that if you make pots for enough of years that you'll
make all the dumb mistakes eventually. From experience, I suspect it's
true. Never load a kiln when you are sleepy or in a huge hurry or both.
I put in a shorter stilt on one corner of a shelf once, didn't notice,
and fired to cone six. Shelves leaned during firing, pots against
wall, pots stuck together Was luckier than I deserved to be!
I would go ahead and put in another thermocouple. This is something
you don't want to be unsure of working!! Small amounts of glaze can be
easily chipped from the soft brick. Be sure to vacuum out afterwards!!!
Good luck!
Darlene
claybair on sun 22 jun 03
So, maybe I'm not as stupid as I thought.
I went ahead used the diamond burr on the thermocouple too.
It removed all the glaze and it only took a few minutes.
It was a relatively thin coating of glaze so wasn't as bad as I first
thought.
Thanks to all for your suggestions.
Gayle Bair
Bainbridge Island, WA
http://claybair.com
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of Roger Korn
Sent: Saturday, June 21, 2003 6:49 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Glaze on thermocouple
I'd suggest using a diamong burr on the Dremel tool. Working carefully,
you should be able to clean it up. Test against a known-good
thermocouple, because glaze traces my introduce an error when they
re-melt. Some of the more strongly polar molecules could introduce an
electrolytic voltage on the order of tens of millivolts - right on the
order of magnitudeof the thermal EMFs that the thermocouple produces.
Worst case, at least in the case of a Type K thermocouple, you can grind
off the welded junction completely and weld a new junction using an
oxy-acetylene torch with a 000 tip. This always works well form me, but
I haven't tried it on anything except a Type K thermocouple.
Hope this helps,
Roger
claybair wrote:
>Well..... I have now had my first glaze firing disaster.
>
>I was in a hurry to load & fire the kiln (L & L JD230).
>The last piece placed was a vase about 1" from the kiln wall.
>It was one of the last pieces glazed. It was a thin walled piece
>the interior glaze too thick. Looking at this retrospectively
>the bisque got saturated and the glaze on the outside didn't adhere.
>I ignored the tell tale slight cracking in the glaze. I saw it and ignored
>it...
>Arghhh!
>
>Of course it was on a top shelf, it didn't just run off the pot ... it
flew!
>The glaze on the outside just ran off the middle of the pot and dripped
>down onto 3 shelves. As if that wasn't bad enough it also jumped
>onto the kiln bricks then jumped 2 inches over to the right to nicely glaze
>the thermocouple, more kiln bricks and kiln floor!
>
>To add insult to injury for some stupid reason I soaked this firing longer
>than
>I usually do which just added to the mess.
>
>My question is what would be the best way to remove glaze from the
>thermocouple?
>It is a heavy duty one. It has been suggested to me to try carefully grind
>it off using my Dremel.
>I do have a diamond bit which has nicely removed the glaze from the shelves
>and element holders. Any other suggestions?
>
>The soft brick on the wall now has a few gouges no deeper than 1/2" and no
>wider than 1".
>Do I have to repair them? I figure I will repair any gouges on the kiln
>floor but hopefully the kiln wash there will protect the brick.
>
>Next question......If some glaze is on the element what should I do?
>
>Thanks in advance for any suggestions.
>
>On the bright side only 3 pieces were ruined & most everything else came
out
>great.
>
>I should never load kilns when exhausted... seems I said this a few years
>ago!!!
>Was dumb and now dummerer!
>
>Gayle Bair
>Bainbridge Island, WA
>http://claybair.com
>
>___________________________________________________________________________
___
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
>
>
>
--
Roger Korn
McKay Creek Ceramics
In AZ: PO Box 463
4215 Culpepper Ranch Rd
Rimrock, AZ 86335
928-567-5699 <-
In OR: PO Box 436
31330 NW Pacific Ave.
North Plains, OR 97133
503-647-5464
____________________________________________________________________________
__
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Arnold Howard on mon 23 jun 03
If glaze remains on a firebrick, it will remelt and embed even deeper
into the brick during the next firing. So I hope you removed all the
glaze from the bricks. The 1/2" deep gouges in the bricks sound like
they are nothing to worry about.
If glaze dripped into a groove onto an element, I don't think you will
be able to save the element. But before replacing the element, make sure
you remove the glaze spot in the element groove. Otherwise it could ruin
your new element.
Sincerely,
Arnold Howard
Paragon Industries, L.P.
www.paragonweb.com
From: claybair
> The soft brick on the wall now has a few gouges no deeper than 1/2"
and no
> wider than 1".
> Do I have to repair them? I figure I will repair any gouges on the
kiln
> floor but hopefully the kiln wash there will protect the brick.
>
> Next question......If some glaze is on the element what should I do?
> Gayle Bair
> Bainbridge Island, WA
> http://claybair.com
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