Bottom Is Cupping Up

[Bill T.]

I was loading a bisque fire today and noticed that a 7" covered casserole that I had made about a month ago was cupped upwards in the middle instead of being flat on the bottom.  Why did this happen?  I put ware on sheetrock to dry, place the lid on the casserole, and if it is real hot outside loosely cover with a plastic sheet. ( We have just dropped into the low 90's after a month of close to 100.)  Using Laguna Speckled Buff, quite a big of grog.  The bottom is about 1/4 -3/16 thick, and I compress it well.  I am thinking the bottom dried too fast in relation to the rest of the casserole.   Any thoughts?

[Mark C.]

Several causes-thats a thick bottom at 1/4 inch-but if the walls are also 1/4 that should not be an issue.

Its a drying issue most likely-

Not much air can get to middle inside bottom and with the lid on its also a moist inner space. Thats my guess

Mark

[Biglou13]

+1 what mark said

 

I think large piece on dry wall, bottom dried faster than rest.

Try drying slower without drywall

[oldlady]

question, why are you covering it with plastic at all? they are both the same consistency when you make them, is it because of added things like the knob and handles?  was it still covered in plastic when you were ready to fire?

 

this is not that uncommon with flat work.  covering the pot helps with the lid fit but it does keep the inside damp.  try removing the lid and letting them dry separately once they become firm leather hard. keep an eye on things as they dry and gently bend it back before it gets too stiff.

 

using the drywall is ok. slide it around to a dry spot occasionally and next time put some weights, (the glass pebbles for flower vases work great) in the bottom.  move it to some kind of wire rack with air under it when it gets very stiff.   if you inspect it as it drys and notice it again,  push in gently from the top before it is too stiff and add more weight.

[Bill T.]

Thanks for the comments.  I did think that it got too dry on the bottom and being closed with the lid kept the inside damper.  Will use some of "old lady" suggestions next time.  The plastic was used mainly for the top had an attached handle, and with the heat we have been having I learned the hard way to try to control drying of the two parts.   

[Biglou13]

Given a box, this box is loosely wrapped with plastic. if only one side is in contact with drywall which of six sides dries faster?