How do I avoid Sculpey cracking problems?
Last Updated on Sunday, 16 March 2008 06:52 Written by Administrator Thursday, 05 October 2006 11:11
Cracking is almost always caused by insufficient curing OR by uneven thickness in the sculpture. (See Baking Times and Temperatures area for layering techniques.) If you ﾓbulk out" the thick areas with foil, and adhere to proper baking times and temperatures, most problems can be avoided. Sometimes the cause can be from baking on an unstable or uneven surface. Always use some type of support under the clay if there are raised portions, as it softens slightly before it hardens in the baking process, and can sag or crack if not properly supported.
If the clay is slightly dry, this can also cause cracking. Add some Sculpey diluent, work in, and the clay will be re-constituted.
Our clays shrink less than 1 percent. This is not enough to cause cracking except in cases where the layer is extremely thin, such as over a glass vessel. Over time, because of temperature and humidity changes, a crack may occur. Sculpey III is by its nature a brittle clay. Premo has a much higher tensile strength, and has a slight resiliency after baking in thin areas.
Sculpey III is strong when used in thick applications, but it can chip when dropped.
