When creating a mold using alginate, a mother mold or shell mold is required to support the alginate mold once it is remove from the model. That is because alginate is not ridged and will collapse on itself. In alginate mold making a mother mold is made either by using overlapping plaster bandage strips or in a second technique, cheese cloth impregnated by rapid setting plaster. Either method is satisfactory.
However, in either method the shell mold will not be attached to the alginate. This means when demolding, the shell mold most often comes off without the alginate mold attached no matter how careful one is. Putting the two together again can be a nightmare in registering the two pieces so that they fit as they were first made. Mis-registering leads to severe mold flaws such a ripples, wrinkles and tears.
A number of experience mold makers have solved this problem by embedding cotton fiber sandwiched between the alginate mold and the plaster shell. Since alginate does not stick to anything, embedding fiber in the alginate before it sets will give your shell mold something to bind to. The technique is to spray the surface of the alginate with Algislo to keep the alginate from setting and to remain sticky enough so it binds to the cotton. When the alginate has cured as the plaster bandages set, both materials will capture the cotton and hold the molds together so they can be removed as once piece.
But not any cotton fiber will do. We have searched high and low and have found the perfect cotton fiber for this technique. It is Kendall cotton. Its fibers are extremely supple and will easily be embed in an uncured alginate surface.
We have provided step-by-step instruction in how to prepare the cotton fiber for use with best practice alginate mold making method below:
|Step 1. Unroll cotton about 8-inches||Step 2. Cut about six inches in width|
|Step 3. Then cut that piece in half so that you have 2-pieces about 6-inch square.||Step 4. Grab on of the squares at each and separate so that the inside shows.|
|Step 5. Use the inside side to pat on to your alginate. This is the fuzzy side.|
Technique. Unroll about six inches of the cotton roll and cut into a six-inch square. Now separate the square into two halves by peeling them in half. The inside of the square has the softest texture fiber. Simply by gently patting the fiber square to the surface of the alginate you will leave behind enough fiber . . . it doesn't need to be a lot . . . to secure the shell mold. One half a pad 6-inch of cotton is all you will require for a torso mold. If the alginate has set, this method will not work. However, by spraying the set surface of your alginate mold with Algislo from ArtMolds, the Algislo will temporarily dissolve the surface enough to embed the cotton fiber.