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hershey8

I Can't See/find My Cone!

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I am starting to wonder if this whole witness cone thing is some sort of "snipe hunt." I placed a large cone 6 self-supporting cone in my kiln the other night. I put it in the center of the kiln in a position that had excellent visibility. My kiln has a "sitter", so I also placed a pyrometric bar there. I shut the door and fired it up. About 4 a.m. I decided to check the progress. I have read that you shouldn't view the interior of a hot kiln without looking through a dark (welder's) glass, because the uv and infrared light can damage your eyes. Having a tendency to believe everything I read, I knelt down, put on some welder's goggles on top of my 2.75 readers and proceeded to look through the tiny peep hole. HA HA HA HA !  "Where is the #$%^^ cone?", a voice inside my sleepy head shouted. All I could see, as my face warmed from close proximity to the kiln's exterior, was maybe the shadow of a shadow. I took off the welder's goggles and tried to look through a piece of welder's glass. That didn't go any better. That's when the whole idea of the snipe hunt came to me, the vision of an inexperienced potter, looking through the world's smallest hole while wearing sunglasses on steroids, trying to find an object that was faint, translucent from heat, and pretty much invisible, while an imaginary crowd of seasoned "ceramists" stood around  snickering. "Fool needs to buy a controller", one imaginary voice said. "And get his eyes checked",  chirped another.

 

SOOOO.....was the witness cone just too far away?  OR IS IT ALL A SNIPE HUNT? And if I continue to hear imaginary voices, should I cut back on my ingestion of cobalt carbonate a bit?    

 

                                            Thanks for listening, er....reading.    john autry

 

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Cones are best viewed when near the peep hole, preferably with something behind it for contrast. As for ingesting cobalt carbonate, there are probably far cheaper thrills to be found in your raw materials -- although I would recommend a nice cup of tea over any of them.

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In contrast to bciske, I put my cones on the far side of the kiln, so they are "silhouetted" against the elements.  Then when the kiln elements are  red/white hot, the cone is dark and shows up against them.  Spend ages on my knees bent round to find the peep-hole and making sure the cones are visible before switching on.  I also wear welder's goggles.

 

For me the biggest problem is leaving an empty space all the way through the kiln, and even with a modern controller, I still like to use the cones - but only check them when firing to ^6.  For bisque I just place them where they'll fit, just so I know the kiln fired properly.

 

I think you're right tho - it's like being on a treasure hunt, except you know there's no gold at the end of the rainbow :unsure:

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In addition to placing the cone on the opposite side of the firing chamber from the peephole, align the cone so the bottom third is silhouetted by the element. Thus, the cone will still be silhouetted by the light of the element after the cone bends.

 

In some kilns, the center elements do not glow brightly even at cone 6. To see the cone, you may need to silhouette it against a top element instead of a center element.

 

Sincerely,

 

Arnold Howard

Paragon Industries, L.P., Mesquite, Texas USA

ahoward@paragonweb.com / www.paragonweb.com

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What temp was your kiln at when you tried to see the cone??? Hope it was over the 500d centigrade mark or  fear for your sanity as well as your eyesight!! May have needed a torch instead of the goggles :D

You didn't think any of this game was going to be easy did you :D

Love hearing about your struggles , makes my life feel almost normal..

What were yo wearing at 4am when seen with welders goggles on, traipsing back to your bed?? Still had them on the top of your head, right??

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Well thanks for the information everyone! I was just really surprised at how vanishing these cones can appear, or should I say, not appear. I'll try to give them a different back drop now that I know. Wouldn't it be great if there was something that would stay dark in the kiln to use for contrast. Don't know what that would be. I'll try the element thing! Thanks again. I appreciate you all.    john a

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I used to fire a kiln that had tiny peep holes. I reamed them out to be larger and it really helped. I also painted a thin stripe of my black ceramic "ink" down the length of the cones. The stripe really pops out when the kiln gets hot. I've also done this using a ceramic pencil, I know this is not supposed to be done, since it might flux the cones slightly, but it really works. I'm with Bruce in putting the cones closer to the spys, too much hassle loading with a clear path to the back of the shelf.

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I always dipped the cone tip in some red iron slip.  Less than a 1/4".  While some say it will provide flux to the cone, I've put 'dipped cones' and non-dipped ones side-by-side in the kiln to see what effect it had; and they bent exactly the same.  Placed the cone pack as close as possible to the peep.  L & L kiln has good sized peeps so it was never too hard to see the cone at Cone 5-6 temps.

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Min and Nairda, thanks for the ideas. I didn't realize that a colorant would show up differently in a yellow-hot kiln. These solutions are certainly worth a try.  Thanks for the suggestions everyone!   john a

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Thought dampness was not so good for cones, pos only referring to sitter cones?

I'm just adding a minuscule amount of moisture with my thin ink stripe, it works better than the ceramic pencil. The ink is a mix of manganese diox, cobalt ox and iron, it's the Robin Hopper recipe, I don't have it handy right now but can dig it out if anyone wants it.

 

I've never noticed any difference with my striped cones over or under firing versus non-striped. I should add that I've used stripes on ^4 through 8 in electric kilns and been able to clearly see them with gas welding goggles (I think the goggles are a 3 or 4)

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I have problems seeing the cones in my small gas kiln. The flames play havoc with viewing the cones, especially in reduction. This stuff is harder than is seems it should be. I agree with Babs: hearing other's struggles validates my own.

 

Jed

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What temp was your kiln at when you tried to see the cone??? Hope it was over the 500d centigrade mark or  fear for your sanity as well as your eyesight!! May have needed a torch instead of the goggles :D

You didn't think any of this game was going to be easy did you :D

Love hearing about your struggles , makes my life feel almost normal..

What were yo wearing at 4am when seen with welders goggles on, traipsing back to your bed?? Still had them on the top of your head, right??

Temp was probably close to 2000f, still have trouble wrapping my brain around the centigrade thing. Goes back to my childhood. Goggles and boxers. I never sleep without goggles, you never know what you might come across in a dream. Laugh some every day! hee hee  :rolleyes:

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I have problems seeing the cones in my small gas kiln. The flames play havoc with viewing the cones, especially in reduction. This stuff is harder than is seems it should be. I agree with Babs: hearing other's struggles validates my own.

 

Jed

Jed, glad to help with the validation thing. :)

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I spoke with Tom at Orton this morning. He  suggested using a backdrop of a dark colored tile, scribed with horizontal lines. He also mentioned that a piece of kiln furniture, colored with something dark, might work. He thinks the tile would provide some contrast and the scribed lines would give a visual reference point to compare the position of the bending  cone to.  A tile of high temp clay could be used over and over, right? A few ways to skin this cat!  Hmmm....white tile, coated with a black wash or glaze, then lines scribed down to the bare tile. Or maybe a high temp black clay body with white lines painted on.  Gonna make me one.....or two.     ja

Min likes this

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This topic has been covered -do a search on it-

A small point laser tool also works-

my suggestion is get several shades of protective wielding glass.

I have noticed that this also gets less of a problem with more experience in setting the cones up to start with-the backdrop will make a huge difference as well as what angle you line then upon the spy port.

Mark

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This topic has been covered -do a search on it-

A small point laser tool also works-

my suggestion is get several shades of protective wielding glass.

I have noticed that this also gets less of a problem with more experience in setting the cones up to start with-the backdrop will make a huge difference as well as what angle you line then upon the spy port.

Mark                                                                  Laser? I'll have to check that out, Mark. More experience will help, too. This is my first witness cone episode. thanks for reply, j

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Temp was probably close to 2000f, still have trouble wrapping my brain around the centigrade thing. Goes back to my childhood. Goggles and boxers. I never sleep without goggles, you never know what you might come across in a dream. Laugh some every day! hee hee  :rolleyes:

 

Like when I was wearing my prescription lensed. sunnies and went to work in a Gallery, customer arrives and I apologise for lack of lights, they looked at me a bit askance, only when I went to the toilet later did I find that I still had my very dark sunnies on......normal glasses still in case! Check before leaving the house.

Min sorry you said none of hte above, just stuffed up.

That was Hersey

I'd like the Robin Hopper black slip recipe please

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Cones are best viewed when near the peep hole, preferably with something behind it for contrast. As for ingesting cobalt carbonate, there are probably far cheaper thrills to be found in your raw materials -- although I would recommend a nice cup of tea over any of them.

Now I'm beginning to understand this whole contrast thing, the more I search, the more I learn. thanks for the info. j

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I'm with you John ! I also struggle with this to the point of sometimes not actually knowing if the cone bent until the kiln has cooled some, and I can see it. At earthenware temperatures a flash light helps, but not so much with cone 6 . I plan to try dark underglaze on a kiln post behind the cone.

Feeling your pain !

Val

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You can cut down part of a soft brick  to a small piece just larger than the cones as a backstop behind cone and put a dark stain on that-the cone will stand out in front-thats an idea.

Mark

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You can cut down part of a soft brick  to a small piece just larger than the cones as a backstop behind cone and put a dark stain on that-the cone will stand out in front-thats an idea.

Mark

GREAT IDEA! That's just what I'll do. I've got a piece of ifb just waiting for that. Thanks Mark.

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Cones are best viewed when near the peep hole, preferably with something behind it for contrast. As for ingesting cobalt carbonate, there are probably far cheaper thrills to be found in your raw materials -- although I would recommend a nice cup of tea over any of them.

Cobalt tea. hmmm

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