Low fire Glaze no longer glossy?

[Elmoclayman]

Hey all,

I have been using Duncan Envision Glaze - IN-1781 - Pumpkin Orange for a number of years in my high school classroom for a jack-o-lantern project. In years past, it has always come out with a nice glossy pumpkin orange color, until this year. For some reason it has been coming out with a Matte finish and I can't figure out why.

 

I fire it in an electric kiln, to a temp of 1880-1900F. I also have bisque ware in the kiln as well, but this has not effected the glaze result in the past. The only thing I can think of is that the glaze is "old." It has sat since November of last year, but I mix it very well before being used. Is there a material I can add to increase the glossy result?

 

Thanks in advance for any suggestions,

Brian

[neilestrick]

Make sure there's not a layer of material settled out hard in the bottom of the glaze container.

[TJR]

BRIAN;

I THINK YOU MIGHT HAVE HIT THE NAIL ON THE HEAD WHEN YOU SAID THAT YOU ALSO BISQUE IN THE SAME KILN. I ALSO DO THIS AT CONE 06, BUT I TRY TO KEEP ALL THE UNFIRED GREENWARE ON THE BOTTOM, AND DON'T HAVE GLAZE WARE ON THE SAME SHELF. I HAVE NOTICED IN THE PAST THAT RED GLAZES DO NOT LIKE THE OFF GASSING FROM BISQUE. THE ONLY OTHER IDEA IS AS NEIL SAYS, YOUR GLAZE HAS SETTLED OUT.

GOOD LUCK!

oops, had caps lock on the entire time. Sorry

TJR

[Elmoclayman]

I think I may have figured it out. I think its a combination of the glaze settling out as well as adding a little too much water to the slightly thick glaze. I am going to try having the students put an extra coat on and see if that helps.

 

@TJR I usually have a shelf dedicated to the glazed projects and then the bisque-ware on separate shelves. I am going to try the glazed ware on the top to see if this makes a difference.