Outdoor Sculpture Claybody Questions

[preeta]

i live in a place where temperatures one season can go upto 110 F and another season hit 32 F and a little bit lower. in a day temperature can range between 30 to 40 degrees. we get frost but no snow. 

 

to understand design i am attempting abstract sculpture forms.

 

the few things i have learnt from this forum are 

1. absorption should not be more than 3%

2. grog in clay weakens clay

 

will glaze help the piece last longer?

 

should the design be carefully planned so that there are fewer pockets to collect water?

 

in other words how would i make my sculpture last longer amongst the elements? are there other considerations?

[Marcia Selsor]

here are known freeze proof clay recipes

Linda Blossom's clay ^6

on a bridge mural in Ithaca , NY

Linda Blossom' ^6 Clay Body

Hawthorne Fire Clay 35

OM #4 Ball Clay 20

Newman Red 20

Fine Grog 20

Silica 200 mesh 15

G200 Feldspar 10

to glaze green use .5% vee gum in glaze

 

Chip Clauson's Freeze proof terra cotta in parks and on walls outdoors in Montana

Chip Clauson's Freeze Proof Terra Cotta Fire to cone 01-1

Batch %v keep losing format. First number is for the batch and second if %

Hawthorne Fire Clay 20 9

C and C Ball 50 21

Red Art 100 43

Talc 15 6

Muddox Grog 50 21

.5% Barium Carbonate

[Benzine]

I think you hit on all the important considerations.  A non-porous body is the important factor.  You also mentioned making sure there are no areas for water to pool.  Once again, a great thing to consider.  If you wanted concave areas, that might gather water normally, you could simply make drainage holes.

 

Glaze can help repel water, but doesn't necessarily make ceramics water-tight.  If the glaze doesn't fit well, it can craze, which would let water through.  This is why it's important that the ceramic itself is vitrified.

 

Like I said, it sounds like you considered all the important factors.  I wish you the best of luck with your sculpture.

[Marcia Selsor]

In some cases glaze can spall if moisture gets behind it and into an absorbent body. I don't know of any commercial clay that fits the bill but maybe a terra cotta fired to a higher end temperature like ^01- ^3 depending on its range. You will need to test.

Marcia

[bciskepottery]

Many clay manufacturers make clays specifically for sculpture, including outdoor sculpture.  If you are not into making your own clay, start with their web page for info. 

 

http://www.lagunaclay.com/catalog/pdf/lcc_guidetoclay.pdf

[Bob Coyle]

I have used different commercial cone 5-6 clays outdoors with no problem. Freeze/thaw here is a problem and I lost several fully glazed cone 04 pieces before I wised up. I would not use any clay that is not fires to full maturity at cone 5 or higher.

[preeta]

I've been walking around the city looking closely at ceramic sculptures and find a lot of them have concrete mixed in them. That was interesting.

 

Just for friends and family a good vitrified claybody would do for now. Which is really sad because i just joined a raku group which i am really enjoying (both for the community as well as physicality of the whole process) and am making sculptural pieces which would look good in a garden.