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Bisquing Paper Clay


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#1 Isculpt

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Posted 22 April 2010 - 10:02 PM

I have been sculpting clay for only a year, and I'm curious about bisquing in general and bisquing paperclay in particular. A functional potter friend told me to bisque my regular clay sculptures as follows: lid open, two lower elements on low for 8 hours (overnight), lid open 6", two lower elements on low for 2 hours, lid open 1", two lower elements on low for an hour, then close lid and turn all three elements to low for 4 hours, then all elements on medium for 4 hours, and then high until cone 05/06 is reached. Is this an appropriate bisquing schedule for clay sculpture? So far, it has worked well, but if I can cut the time -- safely! -- I'd like to do so. More importantly, I am beginning to work in paperclay, and I'd like to know if the bisquing schedule for well-dried paper clay sculpture would be the same.

#2 Chris Campbell

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Posted 22 April 2010 - 10:53 PM

It seems like a firing schedule for a load that might not be totally dry and the
person wants to be 100% sure before they go for heat. If you have put a lot
of time and effort into a large complex sculpture it may be worth sticking with it.

The only way to judge if you can go faster is with more information.

How big is your sculpture? How thick is it?
Is it all about the same thickness or does it vary?
How dry is your piece? How long has it been dried for?
What kind of clay body is it? Some are much more forgiving than others.

As to the paperclay ... once the paper has burned out ... which is quite early in the firing ...
you are left clay ... more porous but still just clay.

Chris Campbell
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#3 Isculpt

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Posted 23 April 2010 - 12:24 PM

It seems like a firing schedule for a load that might not be totally dry and the
person wants to be 100% sure before they go for heat. If you have put a lot
of time and effort into a large complex sculpture it may be worth sticking with it.

The only way to judge if you can go faster is with more information.

How big is your sculpture? How thick is it?
Is it all about the same thickness or does it vary?
How dry is your piece? How long has it been dried for?
What kind of clay body is it? Some are much more forgiving than others.

As to the paperclay ... once the paper has burned out ... which is quite early in the firing ...
you are left clay ... more porous but still just clay.




Thanks, Chris, for pointing out what should have been obvious to me -- that paperclay is just clay when the paper is burned out. Posted Image

As for the sculptures -- they are generally in the 16x16" size, the same as the interior of my kiln (lol). And I try to keep the walls the same thickness, but I'm sure they vary from 1/4" to 1/2". I usually dry them for two weeks, some more and some slightly less, depending on size, etc. I use earthenware, whether I'm making paperclay or using it "as is", and I don't fire beyond 05.

And while I have you -- boy are you going to get tired of seeing my name and reading my questions -- may I ask a totally unrelated question? What do I have to do to get that nice brown antique look to my underglazed pieces? I tried iron oxide, and ended up with a pinkish hue, rather than that old & earthy, brown-in-the-crevices look I was going for. Was the oxide the right thing to use, but the 05 the wrong temperature? Or is there something better that will work in low firing?

Thanks!

#4 Chris Campbell

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Posted 23 April 2010 - 03:56 PM

I use AMACO underglazes most of the time to get the colors I want when I am not using colored clays.

Iron oxides work well for browns too, but there are so many different types ... red, brown, black etc. so you do have to test.
I know some people use manganese oxide for browns but I have not.
I wish I knew more to tell you ... some people use rutile with the red iron oxide to get rich yellows.

Anyone know some better answers???

As to the firing ... it's up to you. If I were going to speed it up I would concentrate on the drying to make sure my work was 100% dry.

Two weeks does not seem very long for a sculpture that thick and large to dry but it depends on your climate.
To test for dryness ... you should be able to rest your hand anywhere on it and not feel any coolness at all ...

Chris Campbell
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#5 Isculpt

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Posted 24 April 2010 - 09:37 AM

I use AMACO underglazes most of the time to get the colors I want when I am not using colored clays.

Iron oxides work well for browns too, but there are so many different types ... red, brown, black etc. so you do have to test.
I know some people use manganese oxide for browns but I have not.
I wish I knew more to tell you ... some people use rutile with the red iron oxide to get rich yellows.

Anyone know some better answers???

As to the firing ... it's up to you. If I were going to speed it up I would concentrate on the drying to make sure my work was 100% dry.

Two weeks does not seem very long for a sculpture that thick and large to dry but it depends on your climate.
To test for dryness ... you should be able to rest your hand anywhere on it and not feel any coolness at all ...


Thanks for the information. Maybe I can make a thin wash of brown AMOCO underglaze to use on top of AMACO underglaze colors.

And I had no idea that two weeks might be inadequate drying time -- thanks for that admonition. I frequently read that one should "be sure it's dry", but I've touched clay work that had been sitting for six weeks in an air-conditioned room, and it still felt cool to me, so I'm having a little trouble trusting my judgment with that method.

I have read that paperclay is very forgiving in terms of drying; that some people even dry their paperclay work in the kiln. Have you done that? I'm asking because I'm wondering if I could shorten that two+ weeks drying time on paperclay sculptures. I'm sweating a particular deadline because as a former woodcarver, I'm just not used to scheduling "wait time" after completing the carving/sculpting of my work before I can finish and deliver it.

#6 Chris Campbell

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Posted 24 April 2010 - 03:52 PM

It does take a while to get used to a longer work cycle but rushing the drying is not the best way to go ...
f you think about a wood analogy, perhaps it's like someone using green wood instead of letting it age and dry.
Sometimes you just have to wait.
Start making another sculpture while it dries. You can have several in process at the same time.

Paper clay might dry faster ... I don't do sculpture so I am not sure.

Try looking at Graham Hay's website where he has a "Paperclay sculptures" link ... he also has links to many other
paperclay artists' sites ... someone might have all the answers for you.

http://www.grahamhay.com.au/

Chris Campbell
Contemporary Fine Colored Porcelain
http://www.ccpottery.com/

https://www.facebook...88317932?ref=hl

TRY ...   FAIL ...  LEARN ...  REPEAT


#7 Isculpt

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Posted 24 April 2010 - 10:44 PM

It does take a while to get used to a longer work cycle but rushing the drying is not the best way to go ...
f you think about a wood analogy, perhaps it's like someone using green wood instead of letting it age and dry.
Sometimes you just have to wait.
Start making another sculpture while it dries. You can have several in process at the same time.

Paper clay might dry faster ... I don't do sculpture so I am not sure.

Try looking at Graham Hay's website where he has a "Paperclay sculptures" link ... he also has links to many other
paperclay artists' sites ... someone might have all the answers for you.

http://www.grahamhay.com.au/


Thanks for the link to Graham Hay's site. I've only just begun to study it and I look forward to reading and learning more....

#8 anthonyfoo

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Posted 12 May 2010 - 01:23 PM


It does take a while to get used to a longer work cycle but rushing the drying is not the best way to go ...
f you think about a wood analogy, perhaps it's like someone using green wood instead of letting it age and dry.
Sometimes you just have to wait.
Start making another sculpture while it dries. You can have several in process at the same time.

Paper clay might dry faster ... I don't do sculpture so I am not sure.

Try looking at Graham Hay's website where he has a "Paperclay sculptures" link ... he also has links to many other
paperclay artists' sites ... someone might have all the answers for you.

http://www.grahamhay.com.au/


Thanks for the link to Graham Hay's site. I've only just begun to study it and I look forward to reading and learning more....




Hello Chris,

Paper clay dries a lot faster than regular clay, especially if you have the help of the sun like we do in Southern California. For thicker and larger pieces, it will take a bit longer, but when a paper clay piece DOES NOT FEEL COLD to the touch, it is dry. The pulp fibers in the paper clay will distribute and normalize the water content across your piece and help wick moisture from deep inside to the outside. This accounts for the faster drying rate of paper clay compared to regular clay.

I usually have several projects going on at the same time so with one drying, I can work on another. Even if a piece is completely bone dry, I know I can always return to it and continue working on it, sometimes months later.

Please feel free to visit my website and blog for more information about paper clay. Hope this helps.




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