Firing Clays and Glazes

[SegaGenesis]

I am a beginner at ceramics and sculpting in general. I bought a ton of supplies after the studio I got a membership at said they required cone5/6 clays and glazes. 

I didn't realize I purchased 06/05 clay and glazes instead of 5/6. The supplies I purchased is nonrefundable. 

I will be purchasing more clay BUT the description for the glazes says most colors can hold up if fired up to cone 6. Generally, is it safe to fire glaze up to a cone 6 if its meant to be fired at 06/05? 

https://www.dickblick.com/products/blick-essentials-gloss-glaze/ here is a link to glaze I purchased. 

 

[LeeU]

Depends on the individal glaze and the individual clay body. Like much in ceramics, "it depends". Others with more knowledge can answer you better, but as a generality, it is very iffy. Just because  they can be "safely" fired to the higher cone also does not mean that they will hold their color and look good. The color changes can be undesirable. I fired some  05 glaze on a cone 5 body fired to ^5.  With several colors I got transparent instead of opaque and brown instead of the original  color. In a few cases the color stayed true, but I didn't want to take a chance of other problems emerging  on the pieces, over time, regarding the integrity of the glaze fit on the body, so I trashed it all. and then got myslef some low fire clay to do it right.

[Chilly]

As Lee said, plus ^05/06 glazes can run when fired to ^6.  If you do try them, make sure the kiln tech knows, and provide cookies to go under to catch any runs.

[Callie Beller Diesel]

Definitely talk to your tech where you’re doing your firing and let them know what happened. Depending on how many mishaps they’ve had in the past, they may or may not be willing to let you even test with catch trays. Kiln shelves are expensive to replace, and grinding them is no fun!

There’s a big temperature difference between cone 06 and cone 6. The 0 should be read as a decimal: it’s a lower maturation point. Cone 05 is hotter than cone 06, but cone 6 is hotter than cone 5. Cones are a measure of heat work: temperature plus time. That’s why when you see cone charts, there’s temperature variations listed according to fast vs slow firing rates. Google Orton cone chart to see what I mean.

However, in reading the product listing, I noticed this part:

Some colors can be applied to soft fired stoneware bisque and glaze fired to mid-range (cone 5/6) while maintaining much of their color value. Color performance at cone 6 varies and is noted on each label.

 

My suggestion is to read the label of your specific purchases.

It looks like these glazes are formulated to be as user friendly as possible to beginners, so they seem unlikely to run too badly at cone 6. It looks like they’re Blick’s version of Stroke and Coat.