Modification Date: 2017-06-21 13:54:32
Member of Group: AS10
You can make a black glaze at cone 10R using only 1% black stain in a 100% calcine:raw mix of Alberta Slip
|Alberta Slip Calcined||50.0||49.5%|
|Mason 6666 or 6600||1.0||1.0%|
|Rate (C)||Temp (C)||Hold (Min)||Step|
Alberta Slip is a great base for black glazes at cone 10 reduction, only 1% black stain is needed to obtain a jet black glossy. Increasing amounts of stain up to 5% move toward a matte black for Mason 6600 (they remain glossy for Mason 6666). Adding 5-10% black stain and 5-7% iron produces a crystalizing intense gunmetal black. Mixtured additions of Mason 6600:6666 (e.g. 1:1, 2:2) produce metallic surfaces.
Like other high-percentage Alberta Slip glazes, you must use a mix of calcined a raw powder. See the preparation page at http://albertaslip.com for more information.
A jet a black glossy glaze for cone 10R is as easy as 1% black stain and 99% Alberta Slip (Mason 6666 or 6600). Of course, the 99% is a mix of calcine and raw material (starting at 50:50).
This is a 50:50 mix of calcine and raw Alberta Slip plus 5 parts Mason 6600 black stain, 5 Mason 6666 black and 7 iron.
A 50:50 mix of raw and calcined Alberta Slip with 5% Mason 6666 stain added. The slurry was ball milled. Fired at cone 10R.
Alberta Slip (50:50 calcine:raw mix) with 1, 2, 3, 4 and 5% added Mason 6666 black stain. Fired at cone 10R. Semi-gloss blacks are produced. Increasing stain percentage above about 3% does not darken the color appreciably.
Calcined Alberta Slip (right) and raw powder (left). These are just 5 inch cast bowls, I fire them to cone 020 and hold it for 30 minutes. Why calcine? Because for glazes having 50% or more Alberta Slip, cracking on drying can occur, especially if it is applied thick (Alberta Slip is a clay, it shrinks). I mix 50:50 raw:calcine for use in recipes. However, Alberta Slip has an LOI of 9%, so I need to use 9% less of the calcine powder (just multiply the amount by 0.91). Suppose, I needed 1000 grams: I would use 500 raw and 500*.91=455.
Out Bound Links
Archie Bray Slip
In Bound Links
You can make a tenmoku from Alberta Slip by adding only 2% iron oxide and 5% calcium carbonate
2003-12-12 - Tenmoku glazes normally contain 10%+ iron oxide, they are extremely messy to use and often have poor slurry suspension properties and are difficult to...
By Tony Hansen+