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To make a temporary mold, use any of the materials such as plaster of Paris, water putty, or crack filler mentioned in the previous chapter on jigs. Mix the plaster or water putty with water and feel around with your hands to break up any lumps. This is important, or else the cast will be imperfect. Now pour the plaster into the box or frame until it covers the metal squid or pattern by at least in. If the box is only about an inch or slightly more in depth, fill it with plaster up to the top. After pouring the plaster wait about an hour before breaking the box or frame apart. Turn the plaster cast over and remove the metal squid or pattern. This is best done with a sharp, pointed knife and prying under the pattern at the head to loosen it from the plaster. You may have to cut all around the pattern with the knife if the plaster covered the pattern to any extent. It will now take about a week or a bit longer for the plaster mold to season and dry before it can be used. In the meantime, you can make a cover for the mold. This can be done by pouring another part in a box, with plaster or water putty, to make a flat, thick cover. You'll get somewhat better results, however, if you use a metal plate almost as wide and long as the plaster cast for a cover. It can be made of brass, copper, or other metal and be from ? to in. thick.
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