|Monthly Tech-Tip |
Robert has done really valuable work in this research, what an amazing range of color! I am so grateful he shared this with the rest of us. Surfaces are unpolished and unglazed. All are fired to cone 6. Browns are missing, they can be made using iron oxide. For blacks, Mason 6600 is also effective. The blues require lower percentages than shown here, as low as 2% can be effective. Likewise with others, there is an optimal amount for each stain, beyond that, with increases in percentage the color intensity increase will drop significantly. There is another reason to keep stain percentages to a minimum: To reduce the impact on body maturity (and firing shrinkage). Blues, for example, can significantly heighten the degree of vitrification, even melting the porcelain. If you plan to marble different colors, keeping stain percentage as low as possible is even more important, unless you can do fired shrinkage compatibility testing, for example, the EBCT test. Need to develop your own white porcelain? See the link below.
Fired to cone 6. These are not glazed. Polar Ice is very vitreous and very white, an ideal host for stains. However there is a caution: It has a high firing shrinkage. If a stain is refractory it can reduce that shrinkage considerably. On the other hand, some stains will flux it and drive the shrinkage even higher. That means if that if high and low shrinkage stained versions of Polar Ice are laminated the firing will create a tension-time-bomb that either exits the kiln cracked or cracks down the road. This work is courtesy of Robert Barritz.
This is the L3954B engobe. But it has 15% Mason 6600 black body stain (instead of the normal 10% Zircopax for white). There is no cover glaze, yet it is durable and absolutely coal black (so a lesser stain % is possible). Lots of information is available for L3954B (including mixing instructions showing exact amounts for water, powder, Darvan). Engobes are tricky to use, follow the link above or below to learn more. L3954B is designed to work on regular Plainsman M340 (this piece), M390 and Coffee Clay, these bodies dry better than porcelains and are much less expensive, coating them with an engobe to get a surface like this makes a lot of sense. This engobe is actually a highly plastic body, but it does not contain enough feldspar to be a porcelain (this is on purpose to match the firing shrinkage of the stonewares).
|Materials||Mason 6255 Stain|
|Materials||Mason 6266 Stain|
|Materials||Frit VO 6200|
|Materials||Frit VO 6255|
|Materials||Mason 6363 Stain|
|Materials||Mason 6304 Violet Chrome Tin|
|Materials||Mason 6308 Stain|
|Materials||Mason 6306 Stain|
|Materials||Mason 6368 Copen Blue Stain|
|Materials||Mason 6027 Stain|
|Materials||Spectrum 2276 Yellow Stain|
|Materials||Mason 6464 Yellow Stain|
|Materials||Mason 6485 Yellow Stain|
|Materials||Mason 6537 Grey Stain|
|Materials||Mason 6386 Blue Stain|
|Materials||Mason 6600 Black Stain|
|Materials||Mason 6021 Red Stain|
Ceramic stains are manufactured powders. They are used as an alternative to employing metal oxide powders and have many advantages.