Modification Date: 2019-01-07 17:14:44
This is the product of a series of tests where the percentage of feldspar was progressively reduced (from 25% originally) to reduce the firing shrinkage (it is important that engobes shrink the same as the body they are on or they will flake or crack off during firing or later during ware use or exposure to the elements). Amazingly only 10% nepheline syenite is needed.
This engobe is very plastic so it sticks well to leather hard clay.
The zircopax makes this fire quite white. If you want black, switch it to 10% Mason 6600. Be careful with other stains, some of them will flux and increase the fired shrinkage.
To mix this follow the instructions on using an engobe at the Digitalfire Reference Library.
Clay is Plainsman H450. The L3954N black engobe was applied at leather hard stage (on the insides and partway down the outside). The G1947U clear glossy glaze over it on the inside produces a deep and vibrant hue (left). The inside glaze on the right is GR10-C Ravenscrag silky matte. The outsides are GR10-J Ravenscrag Dolomite matte with a little added cobalt and iron (for blue and brown).
These mugs are Plainsman H450. Both have a black engobe (L3954N) applied to the insides and half way down the outside during leather hard stage (the insides are glazed with Ravenscrag silky matte and G1947U over the black engobe). The bamboo glazes can thus be seen over the black (upper half) and the raw buff body (lower). The bamboo glaze on the left has 1% iron added to the base G2571A recipe. The one on the right has 3.5% powdered rutile and 10% zircopax added.
Out Bound Links
A white or colored slip applied to clay as a coating. The term "slip" is often used interchangeably with this, but we think of slip more as a decorative, paint-on material/process. The tile industry uses the largest volumes of engobe by far, these are employed as opaque barriers between less-than-wh...
<recipes version="1.0" encoding="UTF-8">
<recipe name="Cone 10R Base White Engobe" keywords="Coming soon." id="136" date="2019-01-07" codenum="L3954N">
<recipeline material="Nepheline Syenite" amount="10.000" added="0"/>
<recipeline material="Silica" amount="20.000" added="0"/>
<recipeline material="Ball Clay" amount="60.000" added="0"/>
<recipeline material="Zircopax" amount="10.000" added="0"/>
<recipeline material="Bentonite" amount="2.000" added="0"/>
<url url="https://digitalfire.com/4sight/recipes/cone_10r_base_white_engobe_136.html" descrip="Recipe page at digitalfire.com"/>
By Tony Hansen