Friadaman Posted August 11, 2017 Report Share Posted August 11, 2017 Hello all, I'm a newcomer to this forum and sculpting with clay, so I'm hoping i'm posting this in the right place: I've got a question which is related to clay shrinkage in air. My purpose is sculpting a giant mask that suppose to be worn by an actor. I've already made a mold from his face, and now I want to sculpt it and I'm considering using sculpting clay since it's cheap. My main concern is from clay shrinkage in air - I'm not gonna put it in the oven, and the process will be long (3-4 months), so it would be exposed to air for a considerable amount. I've read that the shrinkage in air can go from 4% to 15% from it's volume. that would be devastating for me, as I need this mask to fit the actor precisely! Are those facts true? or can clay be used for such precise purpose? would a humid chamber help, or is the shrinkage inevitable? Thanks in advance, Adam. Link to comment Share on other sites More sharing options...
neilestrick Posted August 11, 2017 Report Share Posted August 11, 2017 Several issues here: - The clay must be fired if it's going to be strong enough to use. Raw, dried clay will just break. - By the time it's fired, it will shrink somewhere between 5-12%, depending on the type od clay an dhow hot you fire it. It's unavoidable, it's the nature of clay. - A clay mask will be much too heavy to be worn comfortably. I would make it out of papier mache, or some other lightweight molding material. Link to comment Share on other sites More sharing options...
Friadaman Posted August 11, 2017 Author Report Share Posted August 11, 2017 Several issues here: - The clay must be fired if it's going to be strong enough to use. Raw, dried clay will just break. - By the time it's fired, it will shrink somewhere between 5-12%, depending on the type od clay an dhow hot you fire it. It's unavoidable, it's the nature of clay. - A clay mask will be much too heavy to be worn comfortably. I would make it out of papier mache, or some other lightweight molding material. Thanks for the quick reply! Seems i've failed to explain my process thoroughly - after sculpting in clay, without putting in fire, I'm gonna make a mold out of it and then cast in latex/silicon for the actual mask. I just want to make the shape of the mask out of clay, again this process will take long (few months), so according to what you say - after that time the sculptor will shrink no matter what, right? Thanks again! Link to comment Share on other sites More sharing options...
Tyler Miller Posted August 11, 2017 Report Share Posted August 11, 2017 Your mask will likely shrink 3-5% from wet to dry if made from a conventional clay. Polymer clay (or a non-drying oil based clay) is your best bet for prototyping masks. Link to comment Share on other sites More sharing options...
Friadaman Posted August 11, 2017 Author Report Share Posted August 11, 2017 how about NSP/ Shavant? ( any idea how it deals with shrinkage in air?). very grateful for your help! Link to comment Share on other sites More sharing options...
Tyler Miller Posted August 11, 2017 Report Share Posted August 11, 2017 No sulphur plasteline/chevant is an oil based product and shouldn't shrink in air to any significant degree. Link to comment Share on other sites More sharing options...
oldlady Posted August 11, 2017 Report Share Posted August 11, 2017 friadaman, think about it. clay is a mixture of specific soils and water. when the water evaporates, the solids come closer together. equals shrinkage. Link to comment Share on other sites More sharing options...
Magnolia Mud Research Posted August 11, 2017 Report Share Posted August 11, 2017 Jerry Rothman developed a clay body around the 1960's that did not measurably shrink going from wet to fired. I used it a while back; the clay came from Aardvark as I remember. It is groggy, but took a porcelain slip at leather hard and bone dry stages and fired to a smooth surface. Jerry sometimes worked as a sculptor and has been quoted as saying "modern clay does not have to shrink!" (or something to that effect). LT Link to comment Share on other sites More sharing options...
neilestrick Posted August 11, 2017 Report Share Posted August 11, 2017 Use oil based clay sculpting clay and you should be fine. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.