Thursday, January 21, 2010

Cast Plaques

Create a plaster plaque for a one-of-a-kind gift.


Cast plaques are used when making decoupage projects, school and birth mementos. They can be given as unfinished gifts if you have a fellow crafter in the family or among your friends. They can also be bronzed, or have gold or silver leaf applied around the edges. Plaques can be cast from most rubber, latex, vacuum-formed plastic, plaster or sand molds. Some molds require a release agent, while others are flexible enough without one.


Instructions


1. Add plaster to water in a large mixing bowl, according to package directions. Mix slowly for thirty seconds until all water is absorbed, using a rubber scraper to reduce the number of air bubbles mixed into the plaster.


2. Apply appropriate release agent to your mold. According to plaster artist Michael Delahunt of ArtLex.com, "A release agent for plaster can be a thin clay slip, or several applications of a soft liquid soap or a thin oil. When doing life casting, petroleum jelly works well as a release agent, and it protects the skin too."


3. Level your mold. Australian mold-makers, of Aldax.com, recommend, "...half fill a large open plastic container with sand and level the molds on the surface of the sand for pouring."


4. Place the plaque mold on a vibrating surface, such as a dryer on the air fluff cycle, to force any air bubbles out of the mixture.


5. Allow the plaster in the mold to cure according to package directions.


6. Turn the mold over and gently bend or twist it to pop the plaque onto a towel or other padded surface.


7. Remove any rough spots or crests formed by a over pour using fine sandpaper. Use a steel scraper ground to the desired angle to "...taper the edges of the plaque on an angle. This is called putting a draft on the model," according to plaster artist Dan Kijak. He continues, "Scrape the edge of the plaque with your steel scraper all the way around to give it the proper draft. You need at least 1/16 inch draft. That makes the plaque 1/8 inch wider on the backside than the front."







Tags: release agent, according package, according package directions, package directions, plaster artist, steel scraper