Large Platter Woes Platters cracking after trimming
Posted 04 February 2013 - 02:18 PM
Posted 04 February 2013 - 02:27 PM
My condolences on the demise of your platters....
Posted 04 February 2013 - 08:46 PM
Posted 04 February 2013 - 09:57 PM
there are many ways to do this and whatever works for you is best-here what I do
I really compress them then strike them off with a larger thickness wire so they do not grab back on to the bat
I make sure they slow even dry and flip them over as soon as I can which is when the middle is dry enough. I never let the lip dry out.
After trimming I dry them right side up-again slowly at first.
Make sure that they are not to thin or thick anywhere but even thickness.
You can experiment with another clay body if this is a continuing issue.
The more open bodies may work better for you.
one thing you did not mention was where the cracks are and which way do they run?with the the round or across it?
Posted 04 February 2013 - 10:06 PM
Posted 04 February 2013 - 11:31 PM
Here is a link to the thread that Natania is referring to:
Natania, glad to hear your platters are working out!
Good Elephant Pottery
Posted 04 February 2013 - 11:38 PM
Posted 05 February 2013 - 08:55 AM
If the bottom sagged while trimming, that can cause the crack.
Other have mentioned good practiced. Even thickness is the key and even drying. You can try waxing the rims to slow down the drying on them.
Posted 05 February 2013 - 02:07 PM
I hope this helps.
Posted 05 February 2013 - 05:10 PM
As an aside I should have searched the forums first before posting. Thanks to the moderators and regulars for not posting the "have you tried the search feature before posting" reply. The links posted as well as the replys were very helpful. I have just thrown 2 more to replace the first losses and I will try to keep the rims from drying too fast. Does using wax resist ever prevent the rims from fully drying and increase the risk of cracks during bisque firing?
Posted 05 February 2013 - 08:48 PM
Kiln Repair Tech
Owner, Neil Estrick Gallery, LLC
Posted 06 February 2013 - 08:13 AM
I wax the edges of my large flat slabs. It helps prevent warping as well from uneven drying. The crack straight across the middle sounds like a drying problem maybe due to unevenness. Slow down the drying and get everything even.
Posted 11 February 2013 - 01:08 PM
I really think that in addition to keeping the drying even, trimming the foot ring with the center of the platter well supported is critical. I am certain the last group of platters were lost because I was trimming them on a thrown clay chuck that did not offer any support to the center, and the rim dried too quickly. At least I got a good look at the middle of the platter to verify that the base and rim was even in thickness
Posted 11 February 2013 - 02:31 PM
Hi, one important point is NEVER LEAVE WATER STAGNATING WHILE YOU TURN YOUR PLATES OR OTHER OBJECTS ! AND YOU WILL NOT HAVE TO WORRY ABOUT WET CENTERS. Enjoy potting. Judith
Posted 11 February 2013 - 08:49 PM
This, or some variation of this is something most of us have experienced. Your clay body might be more prone to drying cracks than others, but, Try cutting a round hole in the plastic bag (on the top, in the center)about 4 to 6 inches wide and this should encourage more even drying. If that doesn't work try a different clay body. Geoffrey Borr- "chilpot"- Chilmark pottery