Clear and durable Plexiglas can be formed with heat.
Plexiglas (very commonly misspelled "Plexiglass") is a clear polymer often used to make windows and skylights. It is a thermoplastic, meaning that it softens when exposed to heat. Plexiglas objects are made when sheets of it are heated until soft enough to form shapes using compressed air, vacuum pumps or manual force. The method of melting you choose largely depends on the type of shape that you wish to form the Plexiglas into. Simple bends and curves don't require the whole sheet to be heated, but do require the same high temperatures.
Instructions
1. Place a piece of Plexiglas in an oven and heat it to its forming temperature. That temperature differs depending on whether you are using Plexiglas G or MC (the two basic types of Plexiglas) and on what type of forming you need to do. You can form Plexiglas G two-dimensionally at between 290 and 310 degrees, while Plexiglas MC needs only 275 to 290 degrees for the same process. Three-dimensional forming needs a temperature of of 350 degrees for Plexiglas G and 325 for Plexiglas MC. Heating beyond these temperatures will fully melt the Plexiglas, but will prevent it from re-forming with its full strength and clarity.
2. Melt a small area of Plexiglas over a strip heater. This is a single long heating element used to heat a line along a piece of Plexiglas. The piece can then be bent along the softened line before being left to cool. This technique is only really useful for bends shorter than 24 inches; beyond that there will be a tendency for the bends to take on a bowed shape. The temperatures required are the same as when the Plexiglas is melted in an oven.
3. Form the melted Plexiglas quickly into the shape you want. The forming needs to be completed before it cools down below 275 degrees; the time taken for this cooling depends on the thickness of the material, but is generally less than two minutes.
4. Allow the Plexiglas to cool slowly. If you are melting the Plexiglas in or over a form, don't try and remove it until it cools to a temperature of between 150 and 170 degrees. It should, however, be removed from any form or support before it cools entirely; not doing so risks cracking the Plexiglas as it contracts.
