Since it's gotten warm out here, the clay dries faster-which can be a good thing and a bad thing. The good part is that if it dries quickly, I can do more firings, closer together. I can't do that in winter when it seems to rain all the time, because there's so much moisture in the air it seems to take forever for anything to dry! For larger sculptural pieces, that's actually a good thing.
Remember, if clay isn't dry enough, when the kiln temperature hits 212° (the temperature at which water boils at sea level), give or take a few degrees, the water left in the too-wet clay creates steam and causes the piece to "blow up," as we call it in the ol' ceramics biz. In these instances, when you open the kiln, there is a combination of chunks of now-fired bisque, powder, and shards, which can't be repaired. You have to chuck the whole damn thing in the trash after you've dried your tears.
If it dries too fast, it can cause cracks. Repairing the cracks can be a major pain in the butt; so much so, that I'll often just pitch the whole piece into the reclamation bucket (a bucket of clay and water that I have to re-wedge) and re-work the clay into usable clay later. It's a pain, but it's good that I can re-use clay that hasn't been fired. I keep costs down that way.
So some of the pumpkins slated for Raku do have some minor cracks in their lids. I'm not overly concerned about it at this point, because the one thing I've learned about working with ceramics is that it ain't over 'till it's over, and you just can't control all the variables. And that you have to let go of attachment to results.
O.k., that's three things, but you get the point.
So two things could potentially happen with those lids:
- Nothing. They'll just continue to show those very minor cracks and they won't effect the integrity of the piece at all
- During the Raku process, which heats them up to 1850° very rapidly and cools them very rapidly, the thermal shock could cause the cracks to open more, or even split the lids.
Generally speaking, Raku breaks are clean and you can just epoxy the pieces together. Since Raku pottery is always purely decorative, and these pieces in particular will never be used to hold water (obviously), that may be the option I have to take with these. It may drop the prices slightly, but whatever. They'll still look great, I hope!
Well, back out into the studio today!