Guys, I'm in the midst of doing a little audio upgrade to the Cressida, and I thought that I'd spend a little time to give you more insight into building a fiberglass subwoofer enclosure. Working with FG is stinky and messy, but it's light, strong and a great material to use in many applications. I like to use it for enclosures because you can make a box tuck into tight spots. I have previously made a box for a mk1 MR2 to fit behind the seat. It was compact enough to allow 100% range of seat sliding motion and over 90% recline ability. Anyways, I wanted to use FG in the Cressida to fill up the right side of the trunk since I have a full size spare on the left side, and of course my car needs a fuller sound.
Here's a general list of supplies and tools.
- FG Resin
- Hardener (MEKP. Methyl Ethyl Keytone Peroxide, you can often buy this together with the resin
- Fiberglass mat
- Stir stick
- Scissors
- Hot Glue gun
- Wood for making a trim ring
- Painters tape (2" wide x L=15m, I used 3 rolls)
- Old wax (Nothing fancy, and not 100% required)
- Plastic sheet
- 3M Spray adhesive, Foam & Cloth
or bondo, Spot putty & paint
- Paint brushes (Get about 3, I like mine with shorter stiff bristles. That makes them good for pushing out air bubbles)
- An old container for mixing resin & hardener
- Gloves (cheapie one use throw aways)
- Wiring terminal & wire
- Dremel with sanding wheel
- Measuring tape for making the trim ring
- jigsaw for trim ring
- Drill with bits for screw holes, hole saw for wiring terminal if round, maybe a jigsaw for a square one
- Sander/grinder
- Soldering Iron/crimper
You will also need a subwoofer, but that is generally understood.
I recommend getting the tape, glue sticks, plastic sheet, brushes and gloves from the dollar store since these are going to be one use only.
You can see the cans of resin that I had purchased. I completely used both of them and my box is on the thin side. For the mat, I suspect that I used maybe 15sq.ft. I don't know exactly, that's just a guess. I've got lots here anyways.
Day 1Step 1: Find a suitable location for a fiberglass enclosure.I choose this corner of my trunk. The other side holds a full size spare, and I'd like to keep it there for the time being.
Step 2: Tape the hell out of it!Start by gathering supplies;
Use lots of tape as you don't want to have resin seeping though into your trunk carpet! I did 3 layers here. Work from the bottom to the top and overlay the tape by half it's width.
I ended up using 3 rolls of 2" x 15 meter rolls of tape. I recommend getting tape from the dollar store. There's no sense spending $4/roll at Canadian Tire for painters tape.
I also laid down some plastic drop cloth to help protect the surrounding area and to give myself some more room to work. I've also marked a rough outline to give myself a rough idea of where I want the edges of the enclosure to be.
I've also added a layer of old cheapo car wax to my tape layers. In fact this wax was so old it had started to grow mold? I had no idea that would happen! This helps to aid in making the FG easier to remove from the car
Step 3: More supplies!I cut up the fiberglass mat into strips and squares. This is an inexact science so the sizes are irrelevant, but the squares are about 4x4". The squares are for corners and sharp changes in shape.
Step 4: Get messyNow is the time to mix the resin and hardener together. You can follow the directions for the right amount to mix together. I like to put a little less hardener in the mix so that I have more time to work. I have made a sub box for a mk1, but I'm still a FG noob, so a little extra time works for me. I'm not in any rush. Brush one coat of the mixed resin and then start putting the mat on top and brush more resin into it until it's completely soaked through. Keep repeating the process until you have covered the entire work area. Repeat this as many times as you'd like. I've heard that 3 layers is good.
This shot shows the end of the second layer
Here is the third layer. There's still some white mat showing, but I've run out of resin.
More tomorrow!