PC-70 Copper Red
Like the traditional copper red glazes it's modeled after, PC-70 Copper Red requires a little more care when applying it to your bisque wares.
Below we go though troubleshooting tips to best help remedy any issues you may be having with your fired wares.
HOW IT WORKS:
The formulation of PC-70 Copper Red creates a reduction inside the glaze, turning the normally green copper to a deep oxblood red.
Because the thickness of the glaze application affects the amount of reduction occurring, the glaze must be applied generously.
We recommend the glaze be applied in 3 or more thick coats, allowing each coat to dry completely before applying the next.
Too thin an application will not create enough reduction and will give less than optimal results. We suggest that you create a test tile with 3, 4, and 5 coat sections and fire before using it on a final piece.
LET'S FIGURE OUT WHAT'S WRONG.
Apply Copper Red directly from the jar without thinning.
Use a thick, natural fiber fan or hake brush to apply 3 or more even coats, allowing each coat to dry completely before applying the next.
The dry, raw glaze should be at least 1.3mm thick before firing. If your results are clear or patchy the application is too thin or not applied evenly.
Applying more glaze and refiring will not help, since the reduction materials will have already burned off.
STILL NOT GETTING ACCURATE RESULTS? LET'S TALK FIRING TEMPERATURE.
#2 FIRING TEMPERATURE
Copper Red is at its most red when fired to cone 5.
Firing to cone 6 will give a more purple-red effect, as well as increase the potential for running.
We recommend using witness cones to verify that your firing is reaching the target temperature.
NOT THE FIRING TEMP? LET'S TRY THE CLAY BODY.
#3 CLAY BODY
We’ve found that some clay bodies will react with Copper Red in a way that creates a frosty blue glaze, instead of the deep oxblood red.
Clays that we are aware can create this effect are:
Sibelco Atelier-Masse Wiesse (Studio White Clay)
Sibelco Niger 2002 (Black Stoneware Clay)
This list is not exhaustive and may be updated as we receive new information.
We recommend using Amaco A-Mix White Stoneware (11M) for the results seen on our website.