|Monthly Tech-Tip |
This black engobe, L3954B, is on a cone 6 buff stoneware (at leather hard stage). Because a thin layer works well with this high-opacity engobe it is possible for the slurry to be more fluid, less gelled. An immediate benefit of this is that it dries more quickly (enabling handling of the piece within a few hours). Another benefit is a much more even coverage than would be possible with more a viscous consistency. The thinner layer also means much fewer issues with flaking during drying. However, application of the engobe takes patience, waiting for drips to stop and gelling to set in and hold it in place.
This is the L3954B engobe. 15% Mason 6600 black body stain has been added (instead of the normal 10% Zircopax for white). Of course, a cover glaze is needed for a functional surface, thickly applied engobes must have the same fired maturity as the body for good fit. Lots of information is available on using L3954B (including mixing and adjustment instructions). Engobes are tricky to use, follow the links below to learn more. L3954B is designed to work on regular Plainsman M340 (this piece), M390 and Coffee Clay (it is not a porcelain but has adjustable maturity to be fitted to them if needed). These bodies dry better than porcelains and are much less expensive, so coating them with an engobe to get a surface like this makes a lot of sense.
Engobes are high-clay slurries that are applied to leather hard or dry ceramics. They fire opaque and are used for functional or decorative purposes. They are formulated to match the firing shrinkage and thermal expansion of the body.