search  current discussion  categories  kilns & firing - misc 

underfired glaze problem

updated wed 29 jul 98


John Woods on sat 18 jul 98

Some elements went out in my kiln and part of the load underfired.
After this problem was fixed I refired the pieces that needed it. I got
some mixed results on a salad bowl set. The insides of the bowls came
out fine but the outside was still matted and ugly looking, almost
unchanged from the results of the first firing. I'm thinking about
firing them a third time but everything else in the second load came out
fine. Are these pieces ruined? Any suggestions? I used a translucent
blue cone 06 glaze which I haven't had any other problems with.

Thanks for any help you can give.

Lynn Woods

on sun 19 jul 98

Try warming the underfired pieces in your oven at 200 degrees for 20 minutes.
Then reapply 1 coat of glaze. Refire and see what happens. I have to do this
with some underglazes that I use clean on top of. Glaze just wants to sink
into clay.
Good Luck.
Diane in Miami

on mon 20 jul 98

Hi Lynn!

Sorry to hear about your kiln failure. I had that happen to me, too. I took
the "unfinished" (underfired) wares to a local ceramics studio with a working
kiln, and had the kiln technician fire them for me. The glazes were

After the second firing, the glaze might not fire as perfectly as it might
when the kiln is working properly.

If there are no other potters in your local area, try the community college or
a school with a ceramics program. Usually, the instructor might allow an
outsider to have wares fired, if there is space left over after student work
has been loaded.

It never hurts to know other potters in your area!

Best wishes!

Milton MiltonsLin@AOL.COM

Nanci Bishof on tue 28 jul 98

Try refiring at ^04. The ^06 glaze should tolerate the increase in temp & the
underfired glaze on the outside of your bowls might mature.