Program your firings manually, calibrate the final temperature
Here is an example of our lab firing schedule for cone 10 oxidation (which the cone-fire mode does not do correctly). We need it to actually go to cone 10, the only way to do that is verify with a cone (self supporting cones are the only accurate way). Then make a note in the record for that schedule in your account at insight-live.com.
Context: Controller, Cones, Firing Schedule
Thursday 30th August 2018
Polar Ice at cone 10 reduction. Stunning!
The Polar Ice data sheet has been changed. In the past we have been hesitant about firing it over cone 6. This is because it is just so vitreous
that firing it higher seemed to be asking for trouble (like warping, blistering
). But at cone 10R it is still resistant to warping. And fires this beautiful blue-white. The translucency
, amazingly, is about the same: Incredible! This is among the most incredible pieces we have ever made in the studio here, it is hard to believe it is possible produce this kind of quality in a pottery studio.
Context: Plainsman Polar Ice cone 6 translucent porcelain
Tuesday 28th August 2018
Stunning black silky matte glaze at cone 6
This contains 6% Mason 6666 gunmetal black stain. The base recipe, G2934
, is an excellent balanced-chemistry
host for a wide range of stains to produce equally stunning reds, yellows, oranges, etc. The fritted
version of the recipe, G2934Y
, provides an even better host. This glaze is affected by the clay it is on. The body on the right is highly vitreous
, this has produced a finer texture that glistens in the light. The body on the left is a whiteware having 1% porosity
(Plainsman M370). Firing schedule is also a factor, slower cooling will dull the color more. We use the PLC6DS
Context: G2934Y - Cone 6 Magnesia Matte Low LOI Version, G2934 - Matte Glaze Base for Cone 6
Monday 13th August 2018
DO NOT leave outsides of functional ware unglazed
This mug is made from the strongest porcelain I have, it is so vitreous
that the bare fired surface does not even coffee-stain. So I glazed it only on the inside. That created a time-bomb waiting for hot coffee! Three others did exactly the same. Four other mugs glazed on the outside were fine. Why? Glaze compression
(the inside glaze is pushing outward) is important to avoid crazing
. But, when suddenly heated it pushes harder. Outside surface imperfections, even microscopic in size, provide crack-initiation-points to relieve the stress (the solution is an inside glaze with carefully tuned thermal expansion
or an outside glaze to counter the forces and fill in all the imperfections).
Context: Glaze Compression
Monday 6th August 2018
Mother Nature's Porcelain - From a Cretaceous Dust Storm!
Plainsman Clays did 6 weeks of mining in June-July 2018 in Ravenscrag, Saskatchewan. We extracted marine sediment layers of the late Cretaceous period. The center portion of the B layer is so fine that it must have wind-transported (impossibly smooth, like a body that is pure terrasig)! The feldspar and silica are built-in, producing the glassiest surface I have ever seen (despite this, pieces are not warping in the firings at cone 6). I have not glazed the outside of this mug for demo purposes (a practice sure to fail in a crack when hot coffee is poured in).
Context: B Clay, Clay and dinosaur country in southern Saskatchewan, Vitrification
Monday 6th August 2018
Humbled by Clive Tucker
Clive Tucker and me (Tony Hansen) had a throw-off today. I got beat. I have never had to face a thrower as capable as this! He made the higher mug (on the right, we had 520 grams of clay each). It is a privilege to have, not just talented and artistic customers like this, but also technically capable ones like him. The real winner is the M370 clay we used. Even though it was too soft, neither of us had issues with twisting, it wanted to compete as much as we did.
Context: Plainsman M370, CliveTuckerCeramics.ca
Saturday 4th August 2018
Clay and dinosaur country in southern Saskatchewan
This is the Frenchman river valley and is the home of the "Whitemud Formation" and two of the mines of Plainsman Clays. The Whitemud layers are clearly visible on the badlands side of the valley (half way down on the left). However the Plainsman quarries are on the rolling hills side, where many places can be found having much less over-burden above the white layers. These materials were laid down as marine sediments during the Cretaceous period. Below the Whitemuds are formations from the Jurassic period. A complete T-Rex, dubbed "Scotty", was found nearby and can be seen in the T.rex Discovery Centre in Eastend, Saskatchewan.
Context: Ravenscrag Slip is Born, Mother Nature's Porcelain - From a Cretaceous Dust Storm!
Friday 6th July 2018
Mining the Battle Formation in our quarry at Ravenscrag, Saskatchewan - June 2018
This is the top layer. Battle clay is highly bentonitic, it is the "super hero of plasticity
" in the quarry, it is unbelievably sticky. We have considered it "over-burden" in the past, but now will be looking for ways to employ Battle clay in our products and seeking special-purpose markets for it. Only 10% of this can turn a silt into a plastic throwing body! It is also high in fluxes (melts by cone 6). That means we can use it to improve the fired maturity of bodies, reducing the need for talc. Removal of this layer has exposed the top of the White-Mud Formation, the "A1" layer. A1 is employed in high fire bodies to impart brown color and fired speckle.
Context: A1 Ball Clay
Friday 6th July 2018
Ever wondered why your dealer can quickly get the clay you need?
This is our warehouse. It is really big! There are 20,000+ boxes in stock of almost every kind of clay we make (about fifty). Plus a hundred different ceramic material powders, many of which we buy in truckload quantities. We keep all kinds of equipment and supplies in stock also (in other storage areas), having a total value exceeding that of the clay. This means that when your dealer orders a truckload of clay, materials, supplies, tools and equipment from us, they get it fast.
Wednesday 20th June 2018
Why is there a health warning on the top of each box of clay?
Like any dirt, clays contain quartz. Quartz particles, if inhaled in just the right size, can block the tiny air passages in your lungs. Quartz is all around us, it makes up about 12 percent of the land surface and about 20 percent of the Earth's crust. This label is a reminder to reduce dust levels in your studio and working area. You can see specifics about hazards of any of our products by clicking links (on any manfuacturers website) to view the SDS (Safety Data Sheet). It contains references to where you can learn more about working safely.
Context: Respirable Crystalline Silica
Wednesday 20th June 2018