NOTE: Nick can NOT spend all his time answering technical questions so please don't swamp us with simple stuff that you might find elsewhere. Nick MIGHT answer or not depending upon his schedule... Ergo

idbbb@optonline.net wrote:

>This is a strange question coming from a fan, so please bear with me. I was looking for technical
>information about Yoda all over the web, and i finally ended up here.

>I'm trying to repeat the process (somewhat) of how the first Yoda was created (for my own
>personal use). I have finished modelling the head with an oil based clay, and understand that I
>now have to create a plaster cast and fill that with liquid latex. I read in "the making of yoda"
>articles that they had detached the ears from the original Stuart Freeborn model and cast them
>seperately. But how did they reattach them after the latex dried? By the look of Yoda's ears, I 
>can't find any seam in the skin that would show that they were seperatly created...

>Anyway, yeah. Any help would be greatly appreciated. And, just to add in while I'm on the topic, 
>I'm a GREAT fan of Nick's work. :)


In those days the oils used in the type of clay you are using would migrate into the plaster and later caused the latex to collapse or skin or not cure. In the US some make-up artists would skin the finished model with a spray plastic. In the last few years the foam I have used (GM) was not as sensitive to oil migration and so I suggest that you contact the manufacturer of the foam you intend to use and check with them if the clay you used will be a problem. 

Secondly the modeling of yoda was just the beginning of the process. Remember that there was a SKIN of foam that sat on a skull in which the mechanism was housed. Once you have made your mold of the OUTSIDE you must model into it in reverse the specific thickness of skin that you need in specific areas. The eyelids for example are thinner than the lips. Keep in mind how it will move. Then make a core by casting back into the original mold. DO NOT MAKE THE MOLD THICKER THAN 1 inch or heat will not flow in a satisfactory manner. Then cast the core for the exterior of the skill. Then fit a cast of the arm into that with the index to thumb joint LINED UP with the lips . The skill was a fiberglass skin filled with rigid foam polyurethane which is hollowed out to contain the mechanism as needed 

You must make your plaster casts in Ultracal or similar HARD plaster with low expansion or you will split the original mold. 
  
The ears were separated where they joined wrinkles around the ear and later glued back AFTER THE MECHANISM WAS FITTED. We used thinned contact adhesive which can get leathery over time. A silicone medical glue might be better now. The edges were blended with stippled latex to hide the seams. (remember that there was a seam running the edge of the ears all the way around separating front and back). Some artists don't like that and burn them off with a soldering iron. Can be messy and you need a VERY steady hand to avoid damage. Fumes from that may be harmful so sit in front of a fan if you try it. practice on scrap first with all these techniques. 

Now you are on your own : ) 

GOOD LUCK 

Nick