LIBERACE DOROTHY MALONE JOANNE DRU Sincerely Yours ‘55

In the youtube video (link below) a Karelian potter uses this technique to make cookware. He immerses pieces, while still hot from the bisque kiln, intp a bucket of milk. After a few seconds he withdraws them and they steam-dry quickly. I did not preheat these Plainsman L210 pieces, they were just bisque fired to 1850F. The Russian potter claims to milk-fire his ware to 300-350 degrees, assuming that is celsius I fired these at 500F/hr to 612F (350C), then held for 10 minutes. The surface is smooth and pleasant-to-touch, it is odor-free. The potter claims it retains this surface over many years despite repeated oven use. This clay body, L210, is well suited since it fires to a smooth unglazed surface. Indigenous cultures throughout history have learned how to prepare, cook and store food in terra cotta clays like this, they withstand thermal shock better than vitrified stonewares and porcelains. And continue to service even if they do crack.

The fired bars on the left are Plainsman L215 (with the material we are evaluating). These are a subset of the test bars, cone 4, 2, 02, 04, 06 (top to bottom), ~2150F down to ~1850F. The overlay graph shows pairs of firing shrinkage/porosity lines generated from the data we have been measuring, the descending ones plot increasing density with temperature and the ascending ones plot increasing shrinkage. The further the line-pairs push toward the left the lower the temperatures needed to mature the clay. Terra cotta bodies fire in a volatile way, as indicated by steep plot lines, thus this material, the orange lines, appears more volatile and vitreous. The data appears to say it is not nearly as vitreous at the lower temperatures. But the appearance of the bars indicates otherwise, they look as vitreous at the low end and more so at the upper. Why? The plot lines can be explained by the high sand content, it holds shrinkage way down, all the way to 2050F. And it inflates the porosity. But if that sand was not there, this clay would mature lower than the L215.

Why? Vintage 90s Black Sabbath Ruined My Life Tour 1999 Ozzy Osborne. These are available on Aliexpress (as Drip Pottery or Drippy Pottery) and they are made by a manufacturer that has close control of body Omega HH520 Thermometer Four-Channel J,K,T,E Thermocouple Data L (and thus strength) and the capability to tune the thermal expansion fit of glaze-on-body. It has to fit better than normal because of the absence of an outside glaze. Too low an expansion and the compression (outward pressure) will fracture body (these are thin-walled pieces making them vulnerable). Too high and it will craze. And the glaze is thick, it will shiver or craze with far less forgiveness than a thin layer. And how did they get the glaze on this thick? They likely deflocculated it, up to 1.7 or more, glazed the inside, let it dry, then glazed the outside. These pieces are a visual and technical achievement. If you are a potter you had best think twice before attempting the same.

Potters are used to making dipping glazes that they weigh out and mix from recipes. Hobbyists commonly use bottled commercial brushing glazes. Did you know that a dipping glaze can be turned into a brushing glaze by the addition of Veegum (or Veegum CER) and water? Do you know what a base-coat dipping glaze is? Here is a quick overview: Dipping glazes need to go on to bisque ware evenly, be thixotropic enough to hold on at thickness and drain and dry quickly. But they don't need to dry hard. Brushing glazes need a cohesive slurry that dries slowly and hardens well on drying. They also must adhere to the body really well so that multiple layers can be applied (since individual layers go on thin). Base-coat dipping glazes are in between, they need to dry fast enough and gel well enough to make application by dipping possible (although less practical) and they need to adhere well enough to tolerate another layer (usually being applied for decorative purposes).

Black burning bodies are popular with many potters. They are normally manufactured by adding around 10% burnt or raw umber to an existing buff-burning cone 6 Cartoon Eyeshade Lovely Expression Style Eye Travel Home Use So. Umbers are powerful colorants, they have high iron and also contain manganese (the latter being the primary source of the color). But these clays can be troublesome. First, good kiln venting is needed to avoid breathing the manganese metal vapors for firings going past cone 6. Micro-bubble clouding/gloss-loss in the glazes and blistering/bloating of the bodies are common. But this mug fired perfectly. Why? The umber was added to a cone 10 stoneware instead (and it has fluxed the body to mature at cone 6). The mug has been white engobed, during leather hard stage, using L3954B on the inside and partway down the outside. After bisque it was clear glazed on the inside giving a flawless surface (using G2926B) and dipped in GA6-A Alberta Slip base amber-clear. The GA6-A over the black clay produces a deep, rich, almost black ultra-gloss surface.

L4496, this clay, is the top two bars, fired at cone 4 and 04. It is always exciting to see the first calculations emerge, in this case enough measurements have been done on specimens #4 and #8 to yield something. The bottom bars are Plainsman L215 terra cotta. But Notice I have enough data entered for these cones that Insight-live can calculate Cold‑Resistant Weeding Control Cloth Gardening Weeding Cloth Deg and water absorption, and the numbers are surprising. Specimen #8 has a firing shrinkage of -0.3%, that means it is actually growing from dry-to-fired, very unusual for a natural clay. Notice also the absorption is only 3.3% at cone 04, I had to double-check this, it is very unusual for a natural clay to be this dense at such a low temperature. Even though the surface of the L215 bar on the bottom is much smoother and denser appearing it is actually much less dense (at 12% porosity). The cone 4 numbers are also interesting. The clay is melting at cone 5 (not shown) but the cone 4 bar is not WSM Standard Series Piston Kit 74.15mm Yamaha AR 230 HO [Boat] ( or bubbling and its firing shrinkage is low.

These screen fragment overlays are from the recipe panel at insight-live.com. The table of data shown here is from the SHAB test only. The row numbers are the specimen numbers of each bar. The first five columns are the data we collected by measuring the bars before and after firing (dry length, fired length, dry weight, fired weight). The last three red columns are the results of calculations it does on that data to produce values for drying shrinkage, New 36" 32 LED Amber White Traffic Advisor Stick Bar Emergency L and fired porosity. The graph above charts the firing shrinkage (ascending line) and absorption (descending line) against temperature. These two lines are like a "fired Exalt North Hat Small/Medium FlexSize Charcoal/Black New Paintba fingerprint". Finding meaning in this data enables characterizing the firing behavior of the clay. In the next step, we will compare it to a terra cotta clay body.

These are the same glazes. The slurry of the one on the left had a specific gravity of 1.45, it was creamy and appeared to be good. However, when this bisque porcelain mug was pulled out after the dip it dried so fast that it would not even out around the lip (in spite of my efforts to roll it). To fix this I added water to increase the specific gravity to 1.43 (making it quite watery). Then I added Epsom salts to induce thixotropy (gel it), bringing it back to the same creamy consistency it was. This time it went on evenly and dried slowly enough that it evened out. Notice the darker color, is it still damp. Although the piece dries enough to handle in less than 30 seconds, it does take longer to dry completely because there is more water in the slurry.

These test bars are fired from cone 5 (top) down to cone 06 (bottom). We are processing hundreds of these bars are any given time, managing the simultaneous testing of dozens of body, glaze and engobe projects in our group account at insight-live.com. These took about a month to work their way through our system, all the measurement data has been entered (we will look at that in the next step). These bars show visually how this clay matures across a wide range of temperatures, from most-porous at the bottom to beginning-to-melt at the top. One thing is obvious: Most terra cottas shrink much more as they approach cone 2, commonly reaching 8%, then they begin to expand above that. This one is much more dimensionally stable, it is only shrinking about 3% at cone 2 (the #2 bar).

This is the G3939A recipe (a 90:10 mix of G2934 and G2926B), it normally produces a silky matte if not cooled too quickly. Shown on the left is our original addition of 8% Mason 6021 red stain and 4.5% titanium dioxide. This not only did not produce the desired marbled effect, it actually made it more glossy! A 1.5% titanium addition completely transforms it to what you see on the right. Rutile, as a source of TiO2, is often used for this, but it is high in iron and would completely muddy the red color. Pure titanium dioxide, by contrast, is iron free.