We've seen car audio fabrication transition over the past few decades from flat plywood trim panels covered in headliner material or carpet, to true fabricators building entire car interiors and exteriors entirely from scratch. In this vein, installers are always striving for innovation and new materials that can be pulled from other existing and long-standing trades to take their projects beyond what was previously seen as state-of-the-art. For example, think about the introduction over the years of fiberglass, acrylic, paint, suede, vinyl, laminate and the like that have allowed us to express our drive for something new and different in each vehicle we build.
One material that has seen a lot more use in vehicle interiors in recent years is aluminum. It can be found in everything from instrumentation trim to foot pedals, gas doors, dash trim and beyond. Working with this metal versus a softer material such as acrylic or MDF may seem to be more in the realm of work that a CNC-equipped machine shop would perform, but it's actually not that difficult or different from many materials currently used in the custom fabrication world. And, it can either lend an OEM-like feel to an install, or it can set off even the most simple designs. Elegant, flat aluminum trim pieces can be created pretty easily by using standard woodshop tools - giving installers just one more material on their list of what's available to make their designs reality and make each project different and more interesting than the last.
We'll skip straight to the point, as I'm sure most of us know how to create a jig from MDF for a piece of trim and then transfer that jig into acrylic. However, this is a very important point, and it's the beginning of the process. To cut your final aluminum piece, you won't want to use an MDF jig since a liquidlubricant will be used to minimize wear on our tools. MDF is not resistant to liquids and can deform and become damaged, so a substitute jig made out of a hard plastic is used. I've found that 11/42" acrylic is ideal for its hardness and resiliency. This jig trims out a 7-inch VGA monitor and the factory climate controls in one piece for a seamless OEM-modified appearance.
Use a jigsaw blade with fairly fine teeth that is designed for cutting soft metals (such as the one pictured here) to pre-cut the material out of all of the cutout locations, again leaving about 11/44" to 11/48" material inside the guidelines. Be sure to keep a lot of pressure on the piece itself and don't try to turn the blade too sharply, as the blade can easily bind up and make the piece bounce (which can be pretty unnerving). Safety glasses and gloves are also a good idea at this point.
After using a Sharpie to trace the shape of the jig onto the aluminum stock for pre-cutting, begin by rough-cutting the outside of the shape on the table saw. You'll want to cut about 11/44" to 11/48" outside the guidelines. Aluminum up to a thickness of 11/42" can be cut using a standard 80-tooth blade, but you'll absolutely want to wear a face shield and gloves to ensure that no shavings get anywhere they're not supposed to. Be sure to measure your fence at both the back and front of the blade for proper alignment so that the aluminum doesn't bind and kick back. Use patience when feeding the aluminum stock into the blade.
Using a step drill bit, pre-drill 11/42" holes within designated cutout locations you traced from your jig. This lets a jigsaw blade fit through the aluminum so you can cut excess material from the middle of the opening.