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Low-Fire Teapot Foodsafe?

foodsafe low fire teapot glaze

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#1 BetsyLu

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Posted 23 December 2013 - 02:22 AM

Hi all, 

 

I'm taking a ceramics class and our teacher provided us with ^06 clay. I didn't realize how low-fire that was until it was too late to start my project over...in fact, she had told us that it was ^6 not ^06. I'm a little concerned as I am making a teapot and don't think I will be able to glaze inside the spout, and have read that unglazed areas of low-fire clay are fairly porous and are not generally considered foodsafe. Should I be concerned that the teapot I spent hours and hours on might not be safe to actually use? Any ideas for how to properly glaze the inside of the pour spout? 

 

Thanks!



#2 Mart

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Posted 23 December 2013 - 07:11 AM

Hi all, 
 
I'm taking a ceramics class and our teacher provided us with ^06 clay. I didn't realize how low-fire that was until it was too late to start my project over...in fact, she had told us that it was ^6 not ^06. I'm a little concerned as I am making a teapot and don't think I will be able to glaze inside the spout,


Why not? You pour the glaze out of the tea pot like it was tea. Good idea is to dampen the inside of the spout first, so you do not get too much glaze in there.
 

and have read that unglazed areas of low-fire clay are fairly porous and are not generally considered foodsafe.

Why not? What was the reason given for not being "food safe"?
If clay is fired at proper temperatures, it's should be hard. Underfired clay is weak and porous. (do not take my word for it, I have never used low fire clay)
 

Should I be concerned that the teapot I spent hours and hours on might not be safe to actually use? Any ideas for how to properly glaze the inside of the pour spout? 
 
Thanks!

I see no reason why you can not use it if it's fired at properly.

#3 Evelyne Schoenmann

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Posted 23 December 2013 - 09:37 AM

I second Mart's oppinion. You can glaze the inside, including the spout. You only have to check that the glaze is lead-free and foodsafe. It should be marked on the glaze pot with a sign or an icon "lead-free". Unfired 06 cone clay (or every low fire clay) is not watertight (or tea tight...), so I would glaze outside and inside of your teapot if I were you. I'am sure you will enjoy the teapot once glazed and fired!

 

Evelyne


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#4 Marcia Selsor

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Posted 23 December 2013 - 10:08 AM

Also the glaze can't crackle or it will seep.
The glaze must fit the clay. Sometimes ^06 clays should be fired a little hotter to mature and the glaze needs to fit just right. When the clay is not mature , often the glaze will craze. Do a test first.
Not all low fire clays have this problem.

Marcia

#5 Mart

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Posted 23 December 2013 - 10:55 AM

But why even mess around with this 06 stuff? Sounds like way too much hassle unless you make pots that are used for cooking food in a fireplace.

#6 JBaymore

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Posted 23 December 2013 - 11:06 AM

But why even mess around with this 06 stuff? Sounds like way too much hassle unless you make pots that are used for cooking food in a fireplace.

 

Apparently because that is what she was given to use in a class setting. :)  

 

Like all firing ranges, earthenware (typically 06-04 range) can be done well.  But it takes knowing your materials.  Which... really... all ranges require.

 

Just one more way to work with a certain set of visual and physical characteristics.

 

best,

 

.....................john


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#7 BetsyLu

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Posted 23 December 2013 - 12:17 PM

But why even mess around with this 06 stuff? Sounds like way too much hassle unless you make pots that are used for cooking food in a fireplace.

 

Mart, if I had known it was 06 I would have bought my own clay! Like I said, my instructor told me it was ^6 NOT ^06, I had no idea it was so low-fire until after I finished my 60-hour project :( 



#8 BetsyLu

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Posted 23 December 2013 - 12:22 PM

I didn't realize I would be able to get proper coverage inside the spout by just pouring the glaze through. I'll certainly try that, but I can't help but worry that I'll miss a spot in there! 

 

I heard that bisqued low-fire clay is very porous, and that when water seeps in it can be a good place for bacterial growth. Apparently high-fire clays are generally still food-safe when fired at the proper temperature because they become so much harder and more water-tight, but low-fire clays are still very porous. 

 

Thanks for the feedback! I've done some glaze tests and they all seemed to turn out well, no cracking or crazing. I'm using an underglaze with some clear over the top, so it's pretty simple. I'll be glazing both inside and out, but I won't be able to glaze inside the lip where the lid sits and I'm not sure about proper coverage inside the spout. 



#9 Marcia Selsor

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Posted 23 December 2013 - 12:30 PM

When you glaze the spot, you'll need to let it dry before glazing the outside.Maybe even wait a day. If the spout is too wet, you will have the glaze too thin on the outside.
Good luck.

Marcia

#10 BetsyLu

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Posted 23 December 2013 - 01:29 PM

Good to know! Thanks for the tips. Should I do that with cups too? Glaze the inside first and then wait a day before doing the outside? 



#11 Denice

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Posted 23 December 2013 - 02:54 PM

I would especially if your brushing the glaze, if your dipping you can do the whole cup at once.  Your low fire cups will chip easier you might want to make some extras.      Denice



#12 JBaymore

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Posted 23 December 2013 - 04:05 PM

I've done some glaze tests and they all seemed to turn out well, no cracking or crazing.

 

Take the fired test pieces and paint them liberally with india ink.  Was a minute and then wipe off all the glaze surface well.  THEN look for crazing.

 

best,

 

.....................john


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#13 BetsyLu

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Posted 23 December 2013 - 07:12 PM

I have made plenty of cups haha, hopefully at least a couple turn out okay! I'll also do the India Ink thing, thanks for the tip!

 

Augh, what a headache. Wish my teacher had just given me high-fire clay in the first place like I thought she had!



#14 Evelyne Schoenmann

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Posted 24 December 2013 - 08:21 AM

BetsyLu: I was wondering what kind of teacher tells you 06 cone clay is 6 cone clay. At least the teacher should know! Now the problem with the glazing and firing she left to you. But we are here to help you! Good luck.

 

John: the india ink trick... I almost forgot. Thanks for reminding us.

 

Happy Holidays!

 

Evelyne


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#15 Pres

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Posted 24 December 2013 - 08:28 PM

There are some out there that believe that earthenware teapots are the best. When properly constructed, and fired with a vitreous glaze the less dense clay acts as an insulator allowing the tea to stay warmer in the pot longer. Also these pots are not as prone to thermal shock as porcelain or stoneware. It does not mean that they don't react to extremes, but are less prone to. 


Simply retired teacher, not dead, living the dream. on and on and. . . . on. . . .                                                                                 http://picworkspottery.blogspot.com/


#16 BetsyLu

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Posted 24 December 2013 - 09:52 PM

BetsyLu: I was wondering what kind of teacher tells you 06 cone clay is 6 cone clay. At least the teacher should know! Now the problem with the glazing and firing she left to you. But we are here to help you! Good luck.

 

John: the india ink trick... I almost forgot. Thanks for reminding us.

 

Happy Holidays!

 

Evelyne

 

Well, it's a little community centre class and she's not super experienced herself (she knows next to nothing about glazes as she never glazes her work...very helpful!) but it was very cheap and a way to work with clay again, so I'm not too mad about it. I guess she asked her husband to pick up the clay and he didn't realize there was a difference between 6 and 06, and she just assumed he'd gotten the right clay. At least she figured it out BEFORE I put ^6 glazes on it!



#17 BeckyH

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Posted 29 December 2013 - 10:17 AM

The pottery I work with is all low-fired earthenware and fully glazed, food safe, safe in the dishwasher and in a microwave. We make loads of teapots and decanters and manage to completely glaze them without trouble. Pouring glaze through the spout of a teapot will coat the interior nicely. Running a fine brush or cotton swab through can help break any potential bubbles.

#18 BetsyLu

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Posted 30 December 2013 - 11:48 AM

Thanks for the tip, BeckyH!







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