Post 106 New 'Lava' rock pot

A while ago I posted a shot of Pot 52 with a highly textured surface reminicient of extruded lava. I was surprised at the response to it, no doubt by the many keen growers of australian natives looking for a pot to match some of the raw and textured bark of our trees.

I've been testing other ways to get texture into pots and have only just come back to the 'lava' wall with Pot 80. Here it is just made and still very wet. It's a round semi cascade pot about 300mm diameter.

And here's a closeup. Glaze will be a flat red brown, a little darker than Pot 52, in a few weeks time.

Post 105 Pot 69 in service

A couple of posts ago I showed Pot 69 fresh out of the kiln. It was commissioned for a nice little corky bark elm and here it is all set for the start of a new growing season.

At this point it looks like a harmonious match and will be even better when the tree is in leaf.

That's a nice tree and a sweet little pot even if I do say so myself.
It certainly looks so much better with a tree in it than sitting there empty. Could that be beacuse it's now a happier pot with something useful to do; fulfilled?
I would certainly be a happy potter to have it in my own collection, as I am to see someone else get the same pleasure.

Post 104 Clay shrinkage and deformation test

While my regular RHG has been missing in action I've used a couple of different clays to test them out. Some of the pots I've made from them have been in recent posts. Those pots are still drying and not yet bisqued.

But with the last glaze firing I fired a couple of test pieces of the Walkers Special and the Toast clay; as I have used in the past my now standard shrinkage and deformation tests.

 This picture shows the Walkers in the front and the Toast behind. The Walkers deformation is very similar to that I've seen with RGH under the same firing schedule - my cone 6 schedule. Toast moved far less, no doubt because of the heaving grogging of the body, which will elevate the maturity temperature of the clay and thus see less vitrification. The shrinkage testing pretty much confirms this suggestion.
  

In the shrinkage test I start with a bar of clay and make two marks exactly 100mm apart. Measure again when dry and after final firing. The Walkers shrinkage is 12% and the Toast 9% after glaze firing. RGH under the same schedule shows about 12.5%. The Walkers fired to a nice off white colour.

The big oval I made with the Walkers Special is nearly dry enough to leave uncovered after two weeks under plastic. I mixed in a little more RIO to buff up the final fired colour. It would otherwise be just offwhite.
Here's a picture of it the right way up. You can see the props under the pot that I use to support it while drying, separated from the pot by a piece of newspaper. The same props go through bisque firing with the pot and then are ready to do the same job in glaze firing. The Walkers clay has an amazingly smooth finish almost like it's been burnished. Now there's an interesting test to run some time.

The pot started when wet at 670mm and should now be down to 636mm; to get to 590mm when glazed; just right, if my shrinkage testing is replicated.