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First firing help - fumes? Discoloration? Cone not bent


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Hello,

 
I have a paragon home artist kiln, fired for the first time and have some questions.
 
 I live in a very humid place and after 3 weeks clay was still cool to the touch so I candled it for 2 hours to make sure clay was dry with ramp 100 degrees max 200 for 2 hours lid proppped. I then  put in a cone 05, closed the lid, and used the cone 05 program. I was just doing green ware test tiles and a few with under glaze. They all appear to have come out fine.
 
 1) do i need a vent? I set it up in a converted attached garage that’s approx 150 sq foot with central air, cieling fan and cracked a window. Could smell it through the entire house (1800 sq feet). 
-Are these fumes dangerous? 
-Should I leave an outside door open? Use a fan? Run it on my porch?
 
2) the cone barely bent - does this mean my kiln didn’t get hot enough? Or could it be affected by the fact that I put it in after candling so the kiln was already at 200 degrees? 
- if it means my kiln didn’t get hot enough how do I fix it so my kiln gets to required temp?
- what does this mean for my tiles - can I go ahead and glaze and fire at cone 06 as planned?
 
3) When I opened my kiln it had new brown discoloration around the rim that had not been there before. What does this indicate?
 
 
 
Kiln:
 
https://www.paragonkilns.com/products/home-artist-120
 
I’m using these clays:
 
Amaco 45015Y Moist Earthenware Modeling Clay, Low Fire, Multi-Purpose, 25 White
 
Amaco Low Fire Terra Cotta 77 Earthenware Clay - Moist - 50 Lbs.
 
https://www.amazon.com/gp/aw/d/B0044SET3S?psc=1&ref=ppx_pop_mob_b_asin_title
 
https://www.amazon.com/gp/aw/d/B000KI7QAY?psc=1&ref=ppx_pop_mob_b_asin_image
 
And this underglaze: mayco stroke and coat 
 
Any info / advice at all would be greatly appreciated!
 
 
Best,
Ashley 
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8 hours ago, Ashley78 said:
I have a paragon home artist kiln, fired for the first time and have some questions.
 
 1) do i need a vent?
Yes, a proper vent captures fumes and exhausts them away from people who can breath them in
 
-Are these fumes dangerous? 
 Potentially, yes
-Should I leave an outside door open?
Yes, of course, minimize the chance to breath in fumes
Use a fan?
 Yes of course, done properly to minimize the fumes, not done to spread them throughout the house
Run it on my porch?
 Yes, if that keeps the fumes outside the house
 
2) the cone barely bent - does this mean my kiln didn’t get hot enough?
Post picture of the cone, but yes the amount of heatwork done is indicated by the cone, not necessarily temperature. It may be a soft cone 05 or near so it may be fine for a bisque.
 
 Or could it be affected by the fact that I put it in after candling so the kiln was already at 200 degrees? 
No, not likely - nearly all the heatwork done on clay and glazes occurs in the last 200-250 f degrees of the firing
 
- if it means my kiln didn’t get hot enough how do I fix it so my kiln gets to required temp?
You test and dial in appropriate offsets as necessary. Post a picture of your cone first
 
- what does this mean for my tiles - can I go ahead and glaze and fire at cone 06 as planned?
Yes, you likely can glaze your tiles, this is only a bisque intended to burn out organics and leave the claybody porous enough to accept glaze decoration.
 
3) When I opened my kiln it had new brown discoloration around the rim that had not been there before. What does this indicate?
It indicates off gassing of the firing, get a vent or effectively ventilate, generally firings burn out organics

Misc. clays and products used
Check and make sure of the firing range for all your products and that they are compatible, IE: lowfire clay, lowfire glaze and fire to the appropriate cone
 
And this underglaze: mayco stroke and coat 
Mayco Stroke and coat is a lowfire glaze, not necessarily an underglaze.
 

Your general answers in Red above. Suggested reading or study would be cone theory, heatwork, ventillation, clay, glazes, etc…

A nice quick resource (IMO) among many, is to watch as many relevant videos in the potters round table which should give you a quick and fairly easy start- about bisque.:https://youtu.be/g0v5jYQ1H_c . Other videos throughout the entire series attempt to explain many aspects of pottery in a fairly simple way.

In the beginning, it is a bit overwhelming but fortunately for those that are curious there are many resources to learn from. Many for free as well and although initially overwhelming, worth learning in my opinion.

The above is free, fairly well done and relatively quick to watch each segment. Some other free resources:

https://www.youtube.com/channel/UCmPwfb4p_jgTJgcDn5xNspg/videos

https://digitalfire.com/

https://glazy.org/

and many, many others as well as many, many quality books written.

Finally, your kiln is designed to fire up to 1900f which means you will work with lowfire clays and glazes, cone 04 and below: 06, 05, 04………… per the approximate numberline below.

Approx temp.                          1900f                                                     2232f            2345f

cone# ->____________06____05___04_____03 …………….1____2___………..__6___________10_____>> increasing>>
Often referred as                 Low fire                                                   Mid fire         High fire


 

 

 

Edited by Bill Kielb
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