Gary Beckwith on sat 17 apr 10
Hi all,
I want to try out horsehair raku. I made a batch of terra sig, and have
horse hair and a raku kiln. I have some questions:
1. What is the optimum firing temperature? Searching on the web, I have
found many different temperatures that people use (from 1100F to
Cone06/Bisque), am not sure which one is best. I'm assuming you have to
fire a little higher than the optimum temp, so that the piece drops to
the correct temperature by the time you remove it from the kiln and
you're ready to apply the hair.
2. Can you fire more than one piece at at time? If I fire more than one
piece, even if I leave the others in the kiln, I would think that the
temps of the 2nd and 3rd piece would drop too far by the time I finished
with piece #1. I'm using a converted oil drum for the kiln.
3. Any particular clay body that you use? Do you need grogged clay due
to the temperature fluctuations, or can you use other tighter clays?
Thanks,
Gary Beckwith
Auburn, CA
Sumi von Dassow on sat 17 apr 10
Gary
Temperature: 1100 to 1300, depending on how long it will take you to get
the pot out of the kiln,
the accuracy of your pyrometer, and the exact effect you want. Start
around 1150 and see if you like
the result; if the hairs don't burn, put it back in and go a bit hotter,
if the hairs break and fall off as soon
as they touch the pot, it may be too hot. Wind and ambient air
temperature will also affect your firing
temperature.
You can load more than one piece at a time; you may have to close the
kiln and reheat it after removing
each piece.
Some potters use a smooth body like B-Mix but it is much more likely to
crack from thermal shock.
Try a raku body or paper clay to start with. Micaceous clay works great
(without terra sig) if you can
get it.
Sumi
>
> I want to try out horsehair raku. I made a batch of terra sig, and have
> horse hair and a raku kiln. I have some questions:
>
> 1. What is the optimum firing temperature? Searching on the web, I have
> found many different temperatures that people use (from 1100F to
> Cone06/Bisque), am not sure which one is best. I'm assuming you have to
> fire a little higher than the optimum temp, so that the piece drops to
> the correct temperature by the time you remove it from the kiln and
> you're ready to apply the hair.
>
> 2. Can you fire more than one piece at at time? If I fire more than one
> piece, even if I leave the others in the kiln, I would think that the
> temps of the 2nd and 3rd piece would drop too far by the time I finished
> with piece #1. I'm using a converted oil drum for the kiln.
>
> 3. Any particular clay body that you use? Do you need grogged clay due
> to the temperature fluctuations, or can you use other tighter clays?
>
> Thanks,
> Gary Beckwith
> Auburn, CA
>
>
>
--
Sumi von Dassow
www.herwheel.com
sumi@herwheel.com
Gary Beckwith on sun 18 apr 10
Thanks for the wealth of information on horsehair raku, to all who
responded. Much appreciated!
Gary Beckwith
Auburn, CA
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