• Art Deco D5 kiln firing

    I just put the first hand-pressed clay pressing of the Art Deco panel D5 into the kiln about 5 minutes ago, here it is before closing the lid:

    PICT3059smI adjusted the kiln firing schedule  for “User 4” a little from the previous test firing, I kept the same 5 segment program and holding for 9 hours @ 200º F, but since I want to fire these at a higher temperature- 129º F than I did on the tests I needed to adjust the ramps a bit. Here is what I came up with for this firing on this sculpture, we’ll see how it works:

     

    1. R1: 80º/H to 200º HOLD for 9 hours @ 200º
    2. R2: 60º/H to 1200º
    3. R3: 90º/H to 1700º
    4. R4: 80º/H to 1950º
    5. R5: 60º/H to 2079º

    At the end of ramp 5 and reaching 2079º it has a 10 minute hold to let that heat do it’s work and soak in, much like baking a cake the heat has to get all the way into the center otherwise only the outside is “done” and the inside is not yet at the set final temperature.

    2079º is what we would consider cone 0  (zero)  if they made one, they make cone 01 and cone 1 so the temperature I found seems to have the best color red in this clay that I like would be between those two cones.

    They are properly called “pyrometric cones” and they are little more than a slightly offset pyramidial shaped piece of clay that bends when the heat range it’s made for is reached, it doesn’t measure temperature but it visually shows thta a certain temperature was reached by how far over it bends.

    They are made in about 40 heat ranges, from 022  (1087º) coolest, usually used for decals and glazes,  all the way up to at least cone 14 (2523º) which is the hottest, used for porcellains and high fire clay. 2523º is about 600º hotter than it takes to melt  copper, it’s hot enough to melt aluminum, lead, tin, copper, and it’s more than hot enough to melt cast-iron!

    Here’s an illustration of cones and how they are often used:cones

    Usually used in groups of three, one shows the temperature definitely reached it’s temperature and exceeded it, the center one bends over as shown and that’s just about perfect for showing it reached the desired final temperature without going over it, if the temperature had gone higher than desired (due to  a malfunction or miscalibration  etc) the guard cone would have started to bend too.

    These remarkably simple devices were invented in the late 1700s and are extremely accurate, albeit how far they bend over depends on proper level placement in the kiln, and how the operator interprets how far is “far.”

    I needed to calculate how many hours it will take the kiln to go through the program and shut off, last time with the slightly different schedule it took  36 hours and 39 minutes, now it looks to be 38-1/2 hours give or take a few minutes. It also takes about  a full day to cool down enough to open the lid and remove either the shattered remains,  or a nicely fired sculpture.

     

     

  • Winged dog cast

    90PICT3053The first cast from the new mold

    It took 100# of cast stone and almost 5 gallons of water to fill the mold, after the cast was hollowed out and dried he weighs 90#  The first cast is for myself, I also need to cast one solid, and with the “shims” left intact, as a “master” for future mold making since the original clay model has been damaged.

    I cast a concrete cast today for a client in Nashville for his building restoration/renovation, that one is to sit on top of a now closed off chimney. It took 100# of sand and about 40# of Portland cement to cast that one, unfortunately at 140# give or take, plus about 40# for the wood crate, he will exceed the weight limit for FedEx ground and will have to ship by truck.

    After he sits in the mold for a couple of days, on Monday I can take him out and see how the cast turned out. I also need to drill a hole up into the base for a stainless steel rod which will be used to help secure the sculpture to the top of the chimney through a hole for the rod to slide into.

    I almost finished the model for the “Butterfly child” today, only the face needs to be worked on now to finish it (other than some minor cleanup and the like) I plan to have the model finished if not tomorrow, then this week so I can make the mold before next weekend, probably Thursday I’ll be working on that since I plan to not let the model dry out before molding it, that will also retain the size a bit more but mostly it just needs to get done!

    The toes on the original 1906 sculpture number and odd three per paw as my model does too, why three toes? I have a theory that the original artist decided to accentuate the strength of the claws and toes to give it strength and power, that’s supported in part too by the muscles in the forelegs, the massive power of the paws are the first thing that draws the eye on this, to fit four toes on each paw they would have had to have been modelled smaller, and closer together, the impact of that would have been significantly reduced.

    I searched for what the design might be called in mythology, closest I could find to this is a winged dog in Armenian mythology called an Aralez. It’s almost certain with the waves of immigrants from Europe, Ukraine, Armenia etc in the 19th century that they would have worked in a terracotta factory such as the one that made these and influenced the designs.
    It’s not a griffin or a winged lion, a winged lioness would be doubtfull.

    Here’s a drawing of such an Aralez, of course this is an artist interpretation, but following the mythology it’s a large, strong  dog with wings depicted on the battlefield:

     

    Aralez