Sunday, July 10, 2011

Summer report #2

Here are the results of the triaxial blend. I'm pretty happy with it, as I suspected though there aren't any usable glazes(to my liking anyways.) There are several that I'll use as a base for further tests. I wasn't too surprised about what the results looked like, I am surprised about the raw materials alone. The red clay has what I guess is a very high shrinkage(useful for raw glazing!), the granite kinda looks like poorly fire malcolm davis shino on stoneware and the ash...

The ash is completely unmelted. It looks like velvet and I can easily dust it off the test piece. I use mesquite ash, which is a very hard wood and generally speaking the harder/denser the wood the more refractory the ash. I also wash my ash which according to Phil Rogers rinses away about 25% of the fluxes. I learned early on that mesquite ash used unwashed has a shelf life of about 3-4 weeks. My glossy green ash glaze will go matte mustard yellow over time, weird right? So I wash all of my ash. To keep it consistent I wash several batches, enough to last 2 or more years and then sort of dry mix it all which leaves me with one large source that will be consistent from one batch to the next. This means that I don't have to test my material before I mix each batch of glaze. I will do the same with the granite and red clay. Back to this behaves like other ashes when mixed in 50/50 of 4/4/2 blends which leaves me to believe that the ash is just lacking something on its own to melt and is in fact not too refractory.

I had to make a modification to my blunger by adding pulleys and a v-belt. The motor is 1725 rpms which is much too fast for mixing. These pulleys bring it down to about 400 rpm. I mixed up my first batch a few days ago and it works great. I'm excited to ease some of the strain from my back.


Sunday, July 3, 2011

My summer report.

Not much happening around here. I haven't made any pots in a couple weeks but I did fire the salt kiln with a bunch of pots from my new clay body. I didn't snap a photo but the results were good. No cracking, before I was having all kinds of cracking with backfilled handles and inside footrings(not s-cracks,) and less warpage with plates. The pots also have a higher ring and feel more dense, though I'll have to fire a test in the redux kiln to confirm that.

Just for kicks I ran a triaxial blend with wood ash, local red clay and granite dust. These are 3 materials I can obtain in abundance for free so I thought I'd see what I can do with them. I've used wood ash regularly for years, I use a bit of red clay in one of my glazes and have never used the granite. I'm not expecting to obtain a usable glaze from this test(though that would be ok) but rather I want to see how these materials interact with each other. So we'll see what happens.

I've also spent some time building a blunging blung-o-matic blunger(patent pending.) It has a mounted motor with mixing shaft and a pump so I don't have to get the slip out by hand. It works well with water...the pump is going to be the weak link...I don't know how well it will handle the slip. I'll let you know in a couple of days.

Happy 4th!