Post 36 More on slumping

I did a test a while ago on pyro-plastic deformation - slumping, of the clay I have been using.
On the last firing I repeated that test using the RGH Stoneware as well as the LGH which is its base. It was suggested to me that the RGH which has an iron colourant added to give it the buff colour may be fluxing the clay, making it more flexible in vitrification.

This is a picture of the test pieces. The white one in the front is the LGH.

I can't really say there is any difference.

So what do I do now - start a series of trials on all sorts of different clays, research the firing cycle I'm using to test the level of vitrification, or conduct some work to test a number of additives to change the clay characteristic.

And so I have prepared some samples for the last test above. I've taken 200 gms of my RGH stoneware clay for 8 samples and then added 10gms of either Silica, Aluminium Hydrate, Kaolin, Magnesium Carbonate, Woolastonite, Rutile flour, Talc, Dolomite. I'm most hopeful of the talc test.
These are drying now and so will be a little while before I get to fire them to maturity.
It would be really great to crack this one.