Clay Body for Horse Hair Pottery

[SFKeller]

I'm trying to find a good clay body for the horse hair firing technique.  I purchased the Marcia Selsor DVD but it recommends Coleman Porcelain which is not available from suppliers near me (WV).  (unfortunately it sounds like a really nice clay). Several years ago, I did some initial experimentation with a white earthenware from HighWater which turned out great.  But then they must have changed their formula because the same clay purchased a year later cracked from the thermal shock.  Pots were bisqued to cone 05 so but that appears to be right on the line of the recommendation.  I appreciate recommendations for both wet or dry mix myself clay bodies. I prefer a smoother clay so should I look at incorporating talc over fine grog?  (with proper respiratory equipment). Will be using terra sig on top of the clay body.  Using a friends recipe who has a ball mill right now but I will be trying the one from Marcia Selsor (ball clay + Darvan) as it looks like a great technique.   I appreciate all suggestions.  I'm getting more focused on pottery now and my previous experience is mostly Cone 6 and 10.  Since I don't have regular access to a soda kiln right now it seems like the horsehair and raku techniques will provide me the fun of unexpected results I like to work with.  TIA Sandi

[oldlady]

hi,  where are you in wv, it is a big place.  in fact, if someone like the jolly green giant would stretch it out at all the corners to make it flat, it would be enormous.

coleman porcelain is only made by aardvark.   it is fired to cone 10 and tom makes fabulous things with it.   i have some but cannot fire to cone 10 either.   some day i will ask about sharing one of the many gas or wood kilns nearby.

highwater made a wonderful clay for both slab and wheel work.   it suddenly changed in 2016 and is now too wet or something to work the way it did.   they claim no difference in anything but it doesn't work like it did.  sorry, i have not found a suitable substitute.

are you doing only non-functional work?   terra sig is not a suitable technique for useful items.

[SFKeller]

Thanks for the reply.  So true.  I work for Highways and found out we are the ONLY state totally enclosed by a mountain range, (it surprised me that we are the only one) they may not be high, but they are everywhere.   I'm in St. Albans, near Charleston.   I love visiting Harpers Ferry but it's quite a trip.  Yes, for the horse hair I'm only doing non functional pieces.  I have horses and of course friends with horses so I've been doing some memorial pieces. Right now thrown work with some altering.  I really like working with the terra sig and the feel of the burnished pieces.  And would love to try some of the other techniques especially the salt fuming. But the fragility of them does worry me. I've been very lucky that up until COVID I was able to use the Soda Kiln at Huntington Museums.  They have a wonderful pottery studio and educational workshops. So in addition to the raku learning curve I've been researching building a small wood, gas or soda kiln.  Just have to check out the zoning first and then get brave and do it!  So I'm starting small and planning a top hat style raku kiln first.  I have a small manual electric kiln for bisque and cone 6.  Trying to figure out what pyrometer to buy too. There are a lot of new nuances to learn (and relearn what I've forgotten) and I'm impatient (and get easily distracted when researching because there is so much to try!). 

FYI, so far with my reading what I've found is that I may have been looking in the wrong direction (earthenware) and should try experimenting with clays in the stoneware range.   Found this article https://ceramicartsnetwork.org/daily/ceramic-supplies/pottery-clay/tips-for-successful-raku-firing-a-look-at-raku-clay-bodies-and-kilns/ .  So I may try testing out some light colored stoneware. And Marcia Selsor whose pots I love says she uses the Coleman, or for the workshops recommends a smooth thermal resistant white clay body. So maybe I should test some porcelains but thinking it's so dense, i was leary, but maybe since it's not vitrified it does better with the shock.  It still have to finish watching the DVD so maybe the answer is in there (I probably should have bought the book instead).   I've not used Laguna Clay before but there is a pottery store in South Charleston that carries their clay so that may be an option to try out small amounts without a long drive.   I guess it's always going to be a constant. The search for the perfect clay. 

[neilestrick]

You don't need a raku body. They're usually quite gritty, so you won't be able to get the smooth polished look you want. It's worth trying just about any mid range or high fire white stoneware, or even porcelain, as long as you slow down the cooling after the pots come out of the kiln. Pots for horsehair don't need go all that hot, not anywhere near as hot as raku, because you're not melting a glaze. You only need to go hot enough for the carbon from the burning hair to get trapped in the clay. In fact, if they're too hot the carbon just burns away. Once the hair is on, if you put it in a container that is insulated, it will slow down the cooling enough that the pot won't crack as it cools through quartz inversion. So a can that is lined with  fiber blanket or something like that. Pots that are thin and even in thickness will survive much better.

[oldlady]

sf,   you are in luck.   you know where Blenko glass is, in Milton just down the road off 60.   if you look up Mud River Pottery in milton, you will find susan maslowski who was my first real teacher.   she is within a mile of blenko.   

say hello, ask if you could meet to discuss whatever you want and you will find a marvelous person with so much skill and knowledge that you will be forever grateful to meet her and see her work.  wish i could be there, too.

[SFKeller]

Thank you both!  I still have a few of the earthenware pots I didn't fire since we were having issues.   A cooling chamber is a great idea.  Because I also like to do some handbuilding and altering which causes potential problem areas,  I was wondering about ways to baby them through the quartz inversion stage.   I'm definitely looking for a body that is much smoother than raku so hopefully I will find a nice stoneware.  You are right Susan is a wonderful artist and both her and Bob are both great people.  She is about 40 minutes from me but I don't see her very often. She would be a great resource to reach out to.  I wasn't thinking... or trying to know more what I'm doing so I don't look like an idiot. LOL.  Neil, I've very much enjoyed reading your posts on kilns and kiln building.  It's got me inspired to buy a lot of books!  And start figuring out where I want to get bricks. 

[glazenerd]

Coleman porcelain is made from Grolleg kaolin. Search for porcelain bodies made with this very clean burning/ high white kaolin clay. There are cone 6 versions available. 

Tom