The following is a description of the steps required for the creation of a life cast: I will have step by step photos of all the procedures I post on this page near the end of october.
(Please note: The use of the products mentioned is at the risk of the user!)
Step 1: Life Casting. (face and neck)
Supplies needed: Dp impression cream (or dental alginate), Ultracal 30, plaster bandages, bald cap, a straw, Vaseline, surgical gloves (optional), bucket of clean water, and a bucket of water for washing.
Procedure: The first thing you want to do is organize your work area. Make sure everything is within reach. Pre-cut all of your plaster bandages and cut two, two inch lengths from the straw. Pre-measure the alginate and water. Then have your subject wash his/her face to make sure it is free of oil and have then slick their hair back with hair spray or gel. Next you'll want to apply the bald cap and apply Vaseline to eyebrows, eyelashes, and beard etc.
Now the fun part! First have the subject insert the two lengths of straw into their nostrils (not too far, this is just to keep the nasal passage clear during the procedure). Mix the alginate, this can be done by hand or mixer (with a mixer you get a smoother result). You must work quickly, the alginate sets very rapidly. Depending on the temperature of the water you will have anywhere from 5-8 minutes with the Dp impression cream, and 3-5 minutes with the alginate. 70 degrees F. is about right. Starting first around the nostrils and then the eyes (make sure that you get the alginate right in the corner of the eyes, this is very important to the fit of the final appliance! Oh yeah one more very important thing, make sure the subjects eyes are closed! hee-hee) cover the entire area that you wish to cast.
Once the alginate sets you are ready to apply the plaster bandages. Make sure when you apply the bandages that you work one way on the first layer and work in another direction on the second layer, alternate accordingly. You will need 3 layers total.
When the plaster bandages are cured (about 5-10 minutes), have the subject lean forward and support the cast in their hands. Have them wrinkle their face gently and help them slowly remove the cast. Immediately put wet paper towels inside the cast, covering the alginate. This will help prevent the alginate from shrinking while you mix the ultracal.
Mix the ultracal with your hand (this is where the surgical gloves come in, it makes for easy cleaning of your hand). Mix the stone slowly to ensure you don't get too much air in the mixture. Too many air bubbles makes the finished positive weaker. After you are satisfied that the stone is thoroughly mixed remove the paper towels from the cast and then slowly pour the ultracal into the cast.
Leave the cast over night (or at least 4-5 hours). The ultracal will get quite hot during the curing process, this is normal. Once the ultracal is cured remove the plaster bandages, and use a rasp to file down any sharp edges on the stone. Ultracal is a very hard stone so any sharp edges can be painful (plus they don't look that great).
Well that's about it! Come back in a couple of weeks and I will have directions on how to sculpt a prosthetic. Untill then.....happy life casting!