Plaster Cast Headpiece

This is the Admiral Qob method and has been adopted by the IKV Bayou Serpent. Admiral Qob has been making prosthetics for about 30 years off and on. This is the full long version:

Items needed:
Big black lawn and trash bag
Cheapest possible bald cap
Vaseline
Optional- tissue paper
Plaster bandages
Big area you can easily clean
Plasticine (oil based none-drying clay)
Translucent powder
Cheap plastic pan with 8" high or so sides
Old Newspapers or toweling
A mixing bowl and cheap spatula
A water source
Several pounds of plaster, I use stay-smooth dry wall plaster (note: NOT finish plaster, but the catalysed type) Also very good but may be more expensive is plaster of paris, also it may be difficult to get in a large enough bag.
Good slush molding Latex. Ben Nye or Mehron are good. Right now I prefer Mehron. At least a 4 oz bottle. Cheap latex you can buy at craft and hobby stores are tempting but don't work as well
Castor oil and the same makeup you will use on your face

Take the lawn and trash bag and cut a hole for the head and pull it over the person. cover his/her hair with the bald cap, you might want to tack down the front edges with sprit gum or liquid latex. You will not need to cast the whole face, what I cast is from the nose(not the nostrils) up to the crown of the head and back to the front of the ears. cover the face with a coat of vaseline. I like to put a single layer of tissue over the eyes and eyebrows, you lose some detail around the eyes but usually that is not critical. Cut the plaster bandages into 2" x 6" strips. (approx) Pour warm water into the plastic pan. Apply to the face from the top to the bottom, covering the cheeks and eyes last. I like to do the eyes last to avoid claustrophobia. Be certain not to cover the nostrils! You won't need that for the Klingon forehead. Put on at least 3 layers to get a stiff form. You can't use too much of this. As the bandages dry, it may get a little warm. When it dries, and it may take longer than you expect for it to dry, tip his/her face forward and gently pull it off. Let the mold dry for at least an hour. Take that time to clean up the mess you surely made, you are done with your client, so he/she can wash up and grab a tankard of bloodwine. Clean out the plastic pan and grab some towels or old newspapers. Take some vaseline and coat the inside of the casting with a layer to use as a separator. Place the casting, outside down into the plastic pan and support it firmly with newspapers or toweling. Now to the plaster positive cast. You may want to mix several layers of plaster, several thin layers dry faster than one thick layer. Pour a cup or 3 of plaster into your mixing bowl and add water, mixing until it is smooth and the consistency of thin pudding. Pour a layer into the negative casting and take your spatula to make sure you have the plaster covering the whole casting about 1/2" to 1' thick. When this is fairly solid apply a second coat, and then a third coat. Some folks build a solid block, I don't. If you are making a mold for many pieces, the mold should be very thick, and might be good to make a block, but it is a matter of taste (and cost! Obviously 4 pounds of plaster is cheaper than 15 pounds). Let sit for at least 24 hours, until it is cool dry and hard.

Now you can pull off the plaster bandages and clean most of the vaseline off the positive casting. You may have some defects or air holes, you can mix a little plaster and patch them, if you are in a hurry you can fill them with plasticine. Now the fun starts. Take 1-2 pounds of Plasticine (you can find this at an art supply store)and sculpt your ridge pattern. You may want to texture the piece with pores and wrinkles. When you are happy with it, cover the exposed positive with a thin flat layer of plasticine. Leave a noticeable line of demarcation between the ridges and the plasticine splash guard. Cover the plasticine with a light coat of vaseline as a separator. Place the finished piece back side down in your plastic pan, filling the back side with newspaper or toweling to make it stable if you didn't make a solid block. If the pan is much bigger than the cast, you may want to place a cardboard divider duct taped to the pan to make a proper sized area to place the piece. The area should be at least 2" bigger than the piece or top bottom and sides, i.e, a 4" x 6" piece should be placed in a 8" x 10" hole.

Now for the final plastering, this will take 2 coats. A coat you brush on either with an old brush or with your fingers. You should be careful to make sure you get a good coat that reflects all the detail of your sculpture. Then pour your pan full of plaster and let set for several days until it is fully dried and cured. Then let it sit a day or two longer to be sure. Turn the plastic pan over and carefully remove the finished negative from it. To separate your sculpture from the finished mold can be tricky, especially if you didn't use enough vaseline. I like to have a source of very hot water and a drain. Maybe put the piece in your bath tub and get the water as hot as possible. The hot water will soften the plasticine and let you take your positive out of the mold. Carefully clean the plasticine out of the finished negative, and patch any airholes and irregularities with plaster. Once you are happy with that, you are done with the tough part!

Take your castor oil, you can get a couple ounces of Castor Sealer at a good makeup store for less than $10, and coat the inside of the finished negative casting. You may want to mix a little of your base makeup with the castor oil, that will permanently color the finished latex piece. Now take your latex and pour it into the piece. Pick up the negative and slosh the latex around so that it is evenly coated with latex. You will need to take some time as while the latex is liquid it will want to settle, not a bad thing because it will settle into the areas you want thickest, but you need every part of the negative coated. Ben Nye latex may be a little thinner than Mehron. You will need to use at least 3 coats. The edges can be much thinner. If you are good you can get the edges tissue thin. Let this dry overnight.

Now you can pull the latex piece carefully out of the mold, trim any overflow and patch and air bubbles with a little latex. Powder it to keep it from sticking to itself. You might need to give it a coat of castor sealer to allow you to use regular makeup on it and powder the piece down. Now you can apply your makeup - that's a separate story!