Polystyrene Foam

From RISDpedia

General Overview
AKA Pink / Blue Foam or XPS extruded polystyrene foam. Great for quicker models. Significantly less expensive than the yellow foam. Easily shaped with any SHARP knife. Dull knives will push and pull the foam and give an ugly texture. Soft and very light weight.
Tips, Tricks & How-Tos
Can be cut using the Hot Wire, and using a template, you can easily cut the exact shape you need, or easily make many of the same shape. Great for quick models. Sanding with a medium grit sand paper can leave a nice smooth finish, like that of Neoprene. Gluing Gluing is most often done with 3M Super 77, (Spray 90 will melt it). Make sure to spray both sides you want to bond, then wait until it feels almost dry then press them together. Also make sure not to spray the 77 to closely as the propellent can melt it as well. Double sided tape is also a good solution for attaching the foam for a short time period. Plaster can be applied to the foam in order to create a smoother surface. Wood filler is another alternative for creating a smoother surface. Use a watered down mixture, and add many, MANY layers.
Not Recommended
Usually not suitable for final models. Be careful around computers, foam dust is highly static and can get sucked in and damage them. Do not Spray Paint. (A water based spray-paint such as Krylon H2O will work with out melting the foam if sprayed from far enough away.) Bondo will melt it 3M Super 77 if sprayed too close, the propellant can melt the foam. White glues, and yellow (wood glues) should not be used to glue foams. typically these glues need their water to evaporate in order to dry, and the foam does not let any air in, so it may take for ever to bond. Do not epoxy. Rubber cement will melt the foam as well.
Safety Information
Note: All safety information contained here within is pure recommendation, and its sole purpose is to help students work safer. This should in no way be considered a professional statement or a replacement for reading product information. Please read all instructions included with products before use. Always wear a dust mask or respirator with particle filters when sanding styrene foam.
Availability
Metcalf Store, 1 or 2 inch thickness. $1 per Board Foot Home Depot
External Links

NOTE: All information contained within this article is pure opinion. Although this article is intended to help students, it may contain faulty or misleading information. This article is not to be considered professional opinion or advice, and is in no way a replacement for reading all safety/instructional documentation. Always remember to protect yourself when handling/using hazardous materials, as well as test new techniques before using them on projects/work intended to be handed in or used. RISDpedia and its contributers take NO responsibility for the information contained within. RISDpedia is not an official site of the Rhode Island School of Design.