Wednesday, November 18, 2009

Hand Casts & Clay Sculpting Part 2

From last week, we quickly finished our sculpting and began the process of adding reservoir walls to our pieces. These are the second set of steps to produce a mold of our sculpted piece that be can than cast from producing our very own Prosthetics.

Make sure your "keyholes" (the small dime sized circles) are clean and clear. These give your mold depth to settle in rather than just floating on top of your clay. Think of it as the one connection between your base and your casting material.

Fellow classmate Cindy Sanabria sculpted a a ravaged bite mark. I'm eager to see the cast of this as the prosthetics from this can be used to show a healed bite or a fresh attack with the application of blood.

Here's Jacqueline Olszewski's bullet hole. She was sick last class and missed out on the beginnings, but quickly caught up and actually surpassed some of the other students to make her mold. I think she had to take off last time because she's secretly a super-hero and the universe needed saving.

Here's my "Mark of the Beast" sculpture with reservoir walls all built up. The Reservoir Walls are just what they are named after, they keep all your casting material inside, on the area you want cast. Check to make sure all your edges are firm (about a 1/2-1 inch thick) and don't have any holes. You don't want it to ooze like a sieve when you could have saved your headache by checking twice. Mine didn't need to be this highly built up, especially around the center, but I didn't want to chance anything with my first pour. And of course this is where the majority of your clay will go to during your build.

That glimmery shine you hopefully see along the outside of my sculpting and the keyholes is an application of petroleum jelly. This is our "releaser", and ensures that our casting material, in this case Ultracal 30, won't "lock" to our base. You don't want to pour your mold without it, because then you'll have two joined pieces (your mold & your base) when you remove the clay. This is avoided by simply applying with a small paint brush.

Next you mix your Ultracal 30 with water until you have a honey like consistency. Take a paintbrush or your hand and begin applying. If you use a paintbrush, make sure to have a cup of water to dip into and rinse as the Ultracal dries and can cling to your bristles.

A flurry of dabbing the material gently into the mold is needed to push out any air bubbles that can get trapped inside of your pour. BE GENTLE. The clay underneath is still very susceptible to pressure and you don't want to jab a thumb into it all, ruining your sculpture underneath. Dab and then fill in the rest of your reservoir. Give your mold a gentle shimmy (a gentle back & forth twisting of the hand base) to make sure the Ultracal settles properly.

Everyone got their hands dirty as they poured their molds. As the material began to "kick" the consistency changed from a honey like substance to more of an oatmeal. Adding more water and a bit more Ultracal and mixing thoroughly brought it back to a workable state. The key to remember here is once you mix, it's time to work.

The family that cures together, stays together. 30 minutes on the clock until we can touch them again.

After roughly 30 minutes of curing time, my pour is ready for the "scratch test". Simply take your fingernail and scratch along the surface. If it's not ready, you'll pull back a finger of glop. Don't rush this process and don't pull your mold before it's ready.

And here's the "pull". I simply pulled away my reservoir of clay, releasing my Ultracal 30 mold. It was still warm from the curing process, but ready to be work on. Any clay you have left over can be saved; simply remove any excess Ultracal fragments first. You don't want to go into your next sculpting project and cut yourself on a rogue shard of plaster.

After scraping away some clay from the nooks and crannies, my mold is ready for casting. All in all I am very very pleased with how my mold turned out from my sculpture. It's not too deep and not too big, which will lend itself to easier application to a wide array of body parts, i.e. hands, forehead, etc.

I began applying layers of liquid latex to my mold by simply dabbing on with a torn sponge. Remember you want to apply the thickest coverage to the center and spread out to the rest of piece. This will give you a more feathered edge that will be easier to blend when time for make-up, which of course adds to the believability of your effect. Think of your application like dropping a pebble in a pond; build the layers out in size like a ripple.

Now the liquid latex simply dries until it's ready to be peeled off like a band-aid.

And banished to the dungeon til next week, when I'll pull the latex with powder and brush and apply. Then I will have my very first sculpted prosthetic to apply and paint up. From this mold I can also pull silicone and other materials as I need. I'm not sure which make-up treatment to start with first; the burn or laceration. Any thoughts?

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