Casting will be most successful for resin part geometries that are of a constant wall thickness. Large or very thick parts can cause problems with total resin elimination.
You can bench the part by use of sand paper, buff and jewelers rouge. Clean the area where you attach the sprue with alcohol. Sprue the part on the tree in a normal fashion. Use a Platinum Investment. We have tested the Ransom & Randolph Platinum Investment called “Platinum Investment and Binder” with excellent results. A list of R&R deals can be obtained by calling 800-800-7496. Use the regular directions for flask preparation, investing, and burnout. With regard to burnout, follow the enclosed directions to a temperature of 1600 degrees F (871 degrees C), and then raise the oven to 1850 degrees F for an additional 3 hours. Make sure that your burnout ovens are capable of maintaining this temperature. Also it is advisable to have good air flow during burnout. With oven that can maintain an atmosphere, try to keep the oxygen level between 12 and 18 percent.
Before casting, you can bring the temperature back to room temperature and blow the flask with compressed air (recommended) or just bring the flask to your normal casting temperature and cast the flask.