Sub Box & Amp Rack

Photoshop of the final Project      ACTUAL FINAL RESULT

Materials Needed:
Masking Tape, Aluminum Foil, Polyester Resin, Hardener, Fiberglass Matting, Spreaders & Brushes,
Latex Gloves, Sandpaper, Body Filler, Cardboard, Plywood, MDF Board, Paint.

 Cardboard Templates:

Mock up templates of the "faces" of the boxes so you know how much materials you'll need.

Masking the Trunk:

1. Mask the trunk completely in the area you'll be fiberglassing. Extend the tape at least 3-6" from the area you need to be safe. YOU DO NOT WANT RESIN ON YOUR CARPETS!

2. Cover the initial Masking with Aluminum Foil. Don't skip this step. The foil helps the initial mold "pop" out of the car.

First 2-Layers:

Begin laying the first two layers of glass inside the car. Do not try to pop the mold out until both layers are completely hardened! (I waited 24hrs to be safe)

Popping the mold:
In this picture you can see that even with 2-layers it's still see-throuh... you'll need to add more layers but first pop the mold out of the car. GENTLY pry at the mold and pull it laterally across the bottom of the trunk to release it from the foil. Most of the foil and some tape will stick to it. Peel off as much as you can, but don't worry if you don't get it all... It'll be covered by paint/carpet by the end of the project.

Final 3-layers:
After adding 3-more layers of woven matt for strength, the mold is now opaque and at its strongest. To smooth out the back from the leftover tape/foil, brush a thick layer of resin across the back. Once that Dries it can be sanded, and painted/carpeted. The mold is now ready for the face to be added.

Cutting Access Hole
Cut an access hole in the back to feed your wires into. Make sure its big enough for your hand to fit in! It won't be seen once mounted in the car, so don't worry if it's not perfect.

Amp Rack Framework
Using 1/4" ply, construct the framework for the face of the amp rack. You can see my outlines of the Amps in pencil. Also, cut out holes to feed the wires up to the amps. I've also built the perimeter frame work which is supported with "L" brackets & Wood glue until it's glassed in for good. It sits 2.75" tall so that it will clear the amps when the Face Plate is mounted to it.

Amp Rack Face Plate
Using the amp rack as a template cut another piece of 1/4" ply in the same shape, and cut the "viewing/vent" holes in the face.

Test Fitting before final trimming and fabric layers
Test fit the pieces in the box, and mark where you need to trim excess glass off the box. You want the face plate to sit flush with the sides and bottom of the box. The gap in the top will be filled with fiberglass.

Filler Piece
There is a small teardrop gap in the side of my box that I wanted to sit flush with the face. I decided to make a filler out of wood since it's a little more difficult to stretch fabric flat over that area. Fabric was then laid on top and using resin it will create a first layer for glass to go on top of.

Fabric Layering
Using Fabric (because its cheaper than glass) start laying it over the gaps in the box. Pull it as tight as possible and brush resin across the whole piece. When it hardens you will need to trim the excess off and continue to fill in gaps until you have all the corners and edges as smooth as possible. You will have to do this several times (that's why I use fabric). I find using a 4.5" Angle Grinder with a grinding disk the most efficient way to cut and smooth pieces of the box.

Using Bondo, try to fill in the rough spots and imperfections in the glass. It doesn't have to be perfect. You just want to get the surface as smooth as possible so that the paint (and carpeting) will have as few peaks and valleys as possible.

Start spraying your first coat of primer over the box.
I do the second and third coats of primer in a different color than the first so that i'm sure I got full coverage across the entire area of the box.

Paint the entire box in the color of your choice. I chose flat black because it will draw the least amount of attention to any parts that aren't covered in carpeting.   

MEASURE MEASURE MEASURE... after that... cut the carpet to the size you need to start to cover the areas of the box that will be visible from the trunk. Cover and cut the face plate openings. Pre-drill and secure the face to the box for final fitment with 1" screws. This box is now ready for installation of the amps and wiring!!


I won't detail every step with instructions since you'll be able to follow along with pictures
Similar to the Amp box. Tape, Mold, Trim, Bondo, Glass, Carpet:


WIRING THE SYSTEM: (this doesn't detail every-step, but covers the main parts)

Main Power cable (don't smack your head into the hood like I did)


FRONT DOORS: (follow all the pics to properly remove the door panels)

I then used a hole saw to create a hole to mount the tweeters: