Uro & Celadon not playing nice

[Pat K.]

Hi everyone,

I fired a Uro (clear with ruby red broken up stringers - smooth to the touch) to a Spectrum Celadon - 12x12. I used a slow ramp up 200 dph to 1465 and held 10 min. Of course, there are more rates, but they're up with my kiln in the shed, and I'm here in my chair. The celadon cracked underneath - about 2/3 of the way - but healed. The problem is, you can see the crack because of the clear Uro. My shelf was probably cold - could this have caused that to happen? My question is can I flip and fire, use a more conservative schedule, and hopefully heal the celadon all the way.

I'd really hate to lose this piece - the two colors are really nice together and of course the cost.

Thanks for any and all suggestions.

Patty

[Stephen Richard]

Do you know they are compatible? Did you run a compatibility test before combining them?
You should think of running one now, if you haven't already.
http://glasstips.blogspot.co.uk/2009/08 ... tests.html
That test will tell you if re-firing will work.

[Cheryl]

It's not clear to me whether you are firing Uroboros 90 with spectrum 96? If so, don't. If not, please tell us more.

[Brad Walker]

If not, please tell us more.

Start with your full firing schedule and a detailed description of the crack. A photo would help, too.

And a compatibility test is always a good idea when using glasses from two different manufacturers, even if they're claimed to be compatible.

[Morganica]

Cracked on the way up but healed? That doesn't sound like a compatibility crack. Definitely need some pics and a schedule. But I'd agree that it's probably a good idea to do a compatibility check just in case.

[Pat K.]

Thanks guys for the input. Both glasses were 96. I checked with polarizing film - no halo. I still haven't learned how to reduce the size of a photo so I can post a picture I have it in the kiln right now doing a flip and fire - a little hotter with a little more of a hold. It's still too hot to take out - we'll see. I'll let you know if that worked. I may end up having to cut it up, but I hope not.

Patty