Making a mold of a polymer clay sculpture

conlevhof

Hello, I need help deciding what kind of mold to make for a project of mine. It is a 38 inch long alligator made of a 3d printed base and sculpted on-top with polymer clay. The skin for the project needs to be flexible as this is going to be an animatronic with a lot of movement I was going to make a concrete mold of it and then paint on the foam latex skin, however I was told that wouldn't work. I want the mold to reflect the detail in the alligator, and I need the skin to do the same. I'm unsure however, of where to start. I've tried researching for multiple hours and can't find many good posts on instructions on how to continue. I was considering making a silicone mold but I was told that foam latex won't adhere as good to it as it would to concrete. Any suggestions on how to make a flexible skin for such a large piece? Any suggestions help.

Matt Winston

Hi @conlevhof here's a great course that walks you through the steps for creating an animatronic puppet, from sculpting to molding, casting, and mechanizing.

https://www.stanwinstonschool.com/tutorials/make-a-monster-puppet-rods-cables

As instructor David Monzingo does in the course, I would recommend that you go with a silicone skin for your alligator as it will move very well and look very realistic. Foam latex is also a great material but it will most likely bunch up and crease in a non-realistic way.

Thomas Thors

Matt Winston said:

Hi @conlevhof here's a great course that walks you through the steps for creating an animatronic puppet, from sculpting to molding, casting, and mechanizing.

https://www.stanwinstonschool.com/tutorials/make-a-monster-puppet-rods-cables

As instructor David Monzingo does in the course, I would recommend that you go with a silicone skin for your alligator as it will move very well and look very realistic. Foam latex is also a great material but it will most likely bunch up and crease in a non-realistic way.

I have a question related to this (somewhat). I have followed David Monzingo's course, and I'm getting ready for casting. I have not sculpted in WED clay tho (not easily found in Norway) - but an oil based clay, akin to Chavant/Monster Clay (NSP). I'm wondering if I should substitute some of the products David use in his process, like the Polyester mud, and possibly even the Bondo resin, for something else? Since from what I understand these products are specifically used because of the water based clay used in the sculpture...

Cheers, T.

Ps. Thanks alot for all the great content! I've been a subscriber for several years, and I'm slowly but steadily learning the skills I need to, hopefully, become a professional prop maker one day.

Chris Ellerby

Hi Thomas,

You would not need any moisture barriers to protect the resin/fiberglass from your oil-based clay, but the general mold-making process would be the same.

/Chris

Thomas Thors

Chris Ellerby said:

Hi Thomas,

You would not need any moisture barriers to protect the resin/fiberglass from your oil-based clay, but the general mold-making process would be the same.

/Chris

Thanks Chris,

Does that mean I can skip the bondo resin layer, and start with the polyester mud? Or should I just follow David's process all the way, regardless? I guess the polyester mud doesn't capture fine detail as well as the bondo resin...?

Or, btw, is there any reason I shouldn't follow the process used by Mike Cooke in the Silicone Mask Making course, with gelcoat (Epoxacoat) as a first layer, then the resin/fibreglass layers?

Thomas

Chris Ellerby

Hi Thomas,

While the bondo is acting as a "print" or "detail" coat, it's main use in that course is as a moisture barrier to prevent the resins used later in the molding process from reacting with the water in the clay.

The process Mike Cooke is using would also be a great option for you, as he's working with oil-based clays, and he's using some newer materials that have great properties for this type of mold.

/Chris