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Test Firing Of Rebuilt Paragon Snf24--Pretty Good, I Think. Maybe.


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A friend gave me this kiln several months ago. Since then I have made and replaced the bottom pan, all 12 elements, cut and grooved several fire bricks to match the existing ones, repaired a switch that had a messed up terminal and contact, and replaced a bunch of wires and connectors. Both timer switches had issues, so who needs timer switches? I disabled the timer motors and just manually turn the switches on and off. I had a little trouble getting all of my elements to seat completely, at first. But after firing to cone 04 last night, all but one-the very bottom one, of course- settled into place.  I'll deal with that, down the road. I have an old pyrometer (Paragon, analog) that I stuck into the top peep hole. I placed an 04 bar into the kiln sitter and let her rip. "They say" peep hole is not always the best place to stick your thermocouple, but that's the only place I have right now until I bore another hole. Well, according to my pyrometer, which spell-check keeps flagging as incorrect, the kiln sitter tripped at about 1860 F. I hit the button and turned the kiln back on within a few seconds and was able to get temp up to about 1950 F, at which point I shut it down. I thought maybe I had used the wrong bar, but when I was finally able to examine it, I found that I had used an 04. It is really beyond slumped and dark and a bit shiney, too. SOOOOO, who do you trust? Mr, pyrometric bar or Ms. Pyrometer (knock it off spell-check)? Do I break down and set up a cone or two. And if I do that how do I know that one location isn't hotter than another location. And if it is, and it probably is, what in the heck do I do about it? How many degrees off is an overfire, and underfire? All in all, I'd say this first firing was successful; at least everything came on and shut off, and there were no explosions or short circuits. If I did over fire a little, if glaze won't stick as well because of this, the pots are a pleasing terracotta at 04. They can stay that way if need be. 

                                                    ja

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Sounds like you did a good job with all the work you did on the kiln.

 

I would go with Orton cones any day over the pyrometer. Sounds like you did over-fire if the bar is dark, shiny and beyond slumped.

It shouldn't have been over-fired much at all if you went to 1950, especially if you fired fast, so I would guess your pyrometer isn't accurate.

 

If you stick your tongue on the pots and the pot grabs it a bit then your pots are probably still porous enough to glaze without much trouble. Just don't let your neighbours see you licking your pots. :)

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I suggest that you adjust the Kiln Sitter with a firing gauge and add witness cones to several shelves. I agree that the witness cones are more accurate than a pyrometer.

 

A quick diagnostics pointer for your SnF-24: The elements in the SnF kilns are wired in series. If the top three elements light up, you know that all the elements in the kiln are working. This is because each of the top three elements is wired in series with other elements.

 

Your kiln project was like attending an in-depth maintenance seminar. Congratulations on getting your kiln running.

 

Sincerely,

 

Arnold Howard

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

ahoward@paragonweb.com / www.paragonweb.com

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Not sure what the question is but I would love to see some pictures. Did you use the old electrics that came with the kiln or did you make up a completely new set? Did you follow the old element resistance or did you make up your own?

I copied the number of loops from the old elements and wound new elements from 14 ga element wire I found on the internet. Resistance was not too much of an issue because the kanthall wire was the same gauge, type and length as the original elements. I simply checked them later just to make sure they were real close, which they were.  This was really an interesting project. Making your own elements is pretty easy once you get used to it. Paragon tech support is amazing! In a very short time, I was able to make a winder consisting of an electric drill, a 3/16 coll rolled steel 3 ft shaft, a little bit of wood, a 3/16 "stop", and a stair gauge ( a little brass nut and bolt clip thingie used for marking off stair stringers) which I used to attach the element wire to the shaft. Once each element was wound, I made a pig tail on one end, locked it into my vise and stretched to appropriate length. Piece of cake! If I can share any more details, feel free to pm me at fritter@tds.net. I also replaced  some hook-up wires with high temp 14 ga stranded wire. Paragon is so helpful. Their support people were so willing to share their knowledge with me. This project would have been pretty tough without their help. I own another kiln from another manufacturer whose tech department wouldn't even tell me what gauge wire they used on the elements of their kiln. Hats off to the folks in Mesquite, Tx.

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Well done, not that I have understood the half of it!!

I have had cones slump and go shiny, shutting off the kiln sooner than expected when I have placed it on high. My kiln really jumps up in tempp when on high. At the same time, the witness cones, Orton, are not yet doing their thing so.. Have gauged the sitter etc.

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I suggest that you adjust the Kiln Sitter with a firing gauge and add witness cones to several shelves. I agree that the witness cones are more accurate than a pyrometer.

 

A quick diagnostics pointer for your SnF-24: The elements in the SnF kilns are wired in series. If the top three elements light up, you know that all the elements in the kiln are working. This is because each of the top three elements is wired in series with other elements.

 

Your kiln project was like attending an in-depth maintenance seminar. Congratulations on getting your kiln running.

 

Sincerely,

 

Arnold Howard

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

ahoward@paragonweb.com / www.paragonweb.com

Thanks Howard. You and everyone I've spoken with at Paragon have been so helpful. What a great support team!

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Well done, not that I have understood the half of it!!

I have had cones slump and go shiny, shutting off the kiln sooner than expected when I have placed it on high. My kiln really jumps up in tempp when on high. At the same time, the witness cones, Orton, are not yet doing their thing so.. Have gauged the sitter etc.

Babs, what kind of kiln do you have?

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Cones measure heat work, which is what you need. Temperature means nothing. Check the calibration of the sitter against witness cones to get everything set right, and just use the pyrometer as a ballpark gauge.

I have a bunch of small cones, would rather have the large ones, but these will work, won't they? Maybe just a little slower to bend?

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Sounds like you did a good job with all the work you did on the kiln.

 

I would go with Orton cones any day over the pyrometer. Sounds like you did over-fire if the bar is dark, shiny and beyond slumped.

It shouldn't have been over-fired much at all if you went to 1950, especially if you fired fast, so I would guess your pyrometer isn't accurate.

 

If you stick your tongue on the pots and the pot grabs it a bit then your pots are probably still porous enough to glaze without much trouble. Just don't let your neighbours see you licking your pots. :)

Min, the pyro is old like me. I only have small cones, but will give them a try. That pot licking thing, let;s just keep that between you and me okay? lol

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Australia here, it's a Ward kiln,the manufacturere went out of business many yeara ago but the kiln builder, who knows every kiln ever made, still supplies parts, a great resource, no computer, head and book and prompt replies and service.

Sometimes it seems there are no absolute explanations.  This is pottery thing is full of life lessons, no?

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Australia here, it's a Ward kiln,the manufacturere went out of business many yeara ago but the kiln builder, who knows every kiln ever made, still supplies parts, a great resource, no computer, head and book and prompt replies and service.

Sometimes it seems there are no absolute explanations.  This is pottery thing is full of life lessons, no?

 

Certainly. Makes us pause and watch, or when not watching, pause and think again!  No Absolutes, to paraphrase, "It depends"....

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Thanks John.

 

Looking to get into electric reduction once I find another small kiln to buy or use the one I have. If it eats through elements I want to be able to make my own. Might email you to get a picture of your element set up.

Glad to help anyway I can. Just let me know. j

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