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Stunning black silky matte glaze at cone 6

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 firing schedule.

Monday 13th August 2018

DO NOT leave outsides of functional ware unglazed

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).

Monday 6th August 2018

Mother Nature's Porcelain - From a Cretaceous Dust Storm!

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).

Monday 6th August 2018

Humbled by Clive Tucker

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.

Saturday 4th August 2018

Clay and dinosaur country in southern Saskatchewan

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.

Friday 6th July 2018

Mining the Battle Formation in our quarry at Ravenscrag, Saskatchewan - June 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.

Friday 6th July 2018

Ever wondered why your dealer can quickly get the clay you need?

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?

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.

Wednesday 20th June 2018

Mel Noble at Plainsman Clay's Ravenscrag, Saskatchewan quarry

Mel Noble at Plainsman Clay's Ravenscrag, Saskatchewan quarry

Plainsman extracts 6 different sedimentary clays from this quarry (Mel knows where the layers separate). The dried test bars on the right show them (top to bottom). The range of properties exhibited is astounding. The top-most layer is the most plastic and has the most iron concretion particles (used in our most speckled reduction bodies). The bottom one is the least plastic and most silty (the base for Ravenscrag Slip). The middle two are complete buff stonewares made by mother nature (e.g. M340 and H550). A2, the second one down, is a ball clay (similar to commercial products like OM#4, Bell). A2 is refractory and the base for Plainsman Fireclay. The second from the bottom fires the whitest and is the most refractory (it is the base for H441G).

Wednesday 20th June 2018

G2926S low expansion cone 6 base glaze is here

G2926S low expansion cone 6 base glaze is here

G2926B has proven to be my most durable, crystal clear, non-crazing, easy-to-use general purpose cone 6 base glaze (from dozens I developed). However, some porcelains (e.g. Plainsman P300) need an even lower thermal expansion. G2926S adjusts "B" (by adding low-expansion MgO at the expense of high-expansion KNaO). Yet it has the same gloss. The insides of these P300 mugs use it (with 10% added Zircopax to make white). "S" is not an all-purpose recipe, it could shiver on high silica bodies, use it if G2926B fails an IWCT test for crazing. These mugs were fired using the PLC6DS firing schedule, the outside glazes are G2934Y silky matte with added stains.

Saturday 16th June 2018

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