Things You'll Need
Kydex sheet(s), sized accordingly
Saw, circular or band
Sandpaper, fine grit
Kydex is a type of thermoplastic made of acrylic/PVC that comes in sheet form and in various colors. Kydex has a low melting point compared to other plastics, which allows you to complete projects quicker. Once you mold and cool the Kydex, the material takes on a rigid durability that makes it attractive for use in small molding projects such as sidearm holsters and knife sheaths. It is also used for larger molding products within the home, outside of the home and in various industries like transportation and fabrication.
Heat the Kydex. You need to heat Kydex using a home oven or heat gun before you can begin to mold it to whatever shape you choose. At 320-degrees Fahrenheit, the Kydex will soften and you will be able to work with it effectively. It will continue to soften up to about 390 degrees, but it will burn at 400 degrees. Kydex comes in different degrees of thickness, so lowering the temperature and allowing it to heat up slowly while keeping an eye on it will help prevent blistering.
Place the heated Kydex on or around the item you want to mold. For DIY projects like a gun holster or knife sheath, you want a tight, custom fit. To achieve this, wrap a thin towel or foam around the item before wrapping it with Kydex. The foam provides just enough space to easily release the item from the mold during regular use. Some molds require separate sheets for front and back portions of the Kydex mold instead of one sheet.
Cool the Kydex. Hold the mold in place using clamps. The mold will cool and begin to harden into the correct molded shape in 5 to 10 minutes.
Connect different parts of the mold. You can connect more than one piece of a Kydex mold using screws, rivets or other similar connectors and a drill (for screws) or other appropriate tool.
Cut off the excess Kydex material using a circular saw or band saw. Do not use high speeds to cut because the heat from the saw will melt the Kydex. Sand any rough edges with fine sandpaper.
If you start out with a large sheet of Kydex and are making a smaller mold, cut the Kydex ahead of time to make it smaller and more manageable before you heat it.
If you are using a heat gun around other materials, the heat gun may burn them if it gets too close.