LEXUS SC OWNERS- THIS ENCLOSURE IS FOR SALE! My email address below- contact me for details. This page shows the COMPLETE ILLUSTRATED PROCEDURE for CONSTRUCTING A FIBERGLASS WOOFER ENCLOSURE into the SIDE PANEL of ANY TRUNK, PLUS FABRICATING A SATELLITE RADIO MOUNTING BRACKET and HIDING your SATELLITE ANTENNA in your SPOILER!

Page 1 - Measuring, fiberglassing and sealing SC woofer enclosure (which is now FOR SALE)
Page 2 - Finishing touches, baffle board & wiring the woofer
Page 3 - Fabricating a mounting bracket for the satellite radio and hiding the antenna in a spoiler

Here's a pic of my car, a VERY stock Lexus SC400, with the optional chrome wheels, spoiler and Nakamichi stereo. The only major addition (and hence the reason for this web page) is the custom fiberglass trunk enclosure for my woofer (pictured below), and an AudioVox PnP2 (now upgraded to a Sportster 4) SIRIUS satellite radio - (see page 3 for details on how I mounted that).

As I type this in late 2009, this custom enclosure is still FOR SALE and I'll pay a referral bonus, so please keep me in mind should you know of any 92-99 Lexus SC owners that want the most space-efficient woofer design ever for their car. See below for more details:

Perry's SC400 Fiberglass Woofer Project:

Table of Contents:
Page 1 - Measuring, Framing, Fiberglassing and Sealing the enclosure.
Page 2 - RAAMmat, cutting the front baffle board, mounting/wiring the woofer and smoothing the enclosure. List of materials used. Fiberglassing tips.

Be sure to check out the "Favorite Links" shown above to see the web pages that influenced me and explained the fiberglassing techniques I used to construct my woofer enclosure. They are very informative- check them out if you want to learn the basics of fiberglassing. To keep my page reasonably small, I’ll just cover specifics of the installation for my car, so it might only be of interest for those building enclosures into the sides of vehicles (in my specific case, the driver's side trunk of a Lexus SC400).

Here’s what the side trunk cavity looks like when the interior trim panel is removed. That taillight assembly on the left has some difficult curves- I should have used modeling clay to smooth it out. Notice the vertical structural panel to the right- the rear edge is not welded to the body, so I bent that edge towards the power antenna assembly to give me a bit more room.

I taped up some cardboard panels to smooth out parts of the cavity

Using tape and spray adhesive, the entire cavity is foiled off.

Here is the water test or the "how do I find out the interior volume of my enclosure" test. Based on many favorable postings from SoundDomain members, I planned to use a 12" Infinity Perfect woofer, which does best with 1 to 1.5 cubic feet of airspace. I mocked up a temporary panel in the position where the front woofer baffle board would be, braced it with some cinder blocks and then stuffed several garbage bags in the interior cavity. Then I filled them with water- I got up to six gallons (0.8 cubic feet) before I stopped. Since I saw there was still plenty of room left, I knew I had at least a cubic foot or more. Also, I started getting worried about a leak- could you imagine the damage that six gallons of water would do to my trunk?

As I was about to line the entire interior area with fiberglass cloth, I realized that there were many flat areas that might be better handled by using wood panels, minimizing the use of fiberglass. This was my first fiberglass project ever, so I was on the cautious side. Besides, I had just plunked down ten bucks for a 4'x4' panel of 3/4" medium density fiberboard (MDF), so I needed to use it up somehow! So I made up some cardboard templates to ensure they fit properly, and then cut and glued 6 panels together. This was just a preference of mine- there's nothing stopping you from using fiberglass for the entire cavity. Anyway, you can see all the glued panels of the MDF below. Outside of the car, it sure looks like a weird, flimsy contraption. If you use MDF for small flat surfaces, 1/2" or even 1/4" MDF is sufficient- 3/4" was definitely overkill. But one advantage was that the thicker MDF along the top and bottom edges provided a ready-made surface to screw the front board to.

Here are the glued wood panels (the "frame") with the first layer of fiberglass cloth glued into the curved areas. That small yellow foam roller you see was very useful for applying and smoothing out the tin foil, then for pressing the fiberglass cloth firmly against the adhesive-sprayed foil, and then was even better at quickly spreading the resin! They are 3" wide- I cut each one into 1" wide pieces and used them that way. I highly recommend them over a paintbrush. You need to work fast, though- the resin eats away at the foam and it starts to break apart in 5 minutes! I used small (3-4 oz.) batches of resin, which take about 5 minutes to spread anyway, so it worked out perfectly.

After 2 layers of (sloppily applied) fiberglass cloth, it is stiff enough to remove from the trunk (finally!). Here is what it looks like (the tin foil stuck to the outside can be wire-brushed off):

Here is the upper front corner after a "patch" job- I needed to create some clearance for the trunk lid support beam (you can see this beam in the top right corner of most of the pics above). I cut away the panel that was in the way with tin snips and a hack saw, and then placed a wooden dowel (a chopstick, actually!) to support a piece of mat that I spanned across to close off the area. It is just amazing how awful this all looks. Fortunately, this area will not be visible once installed.

Here is the box a week later- I've added several layers of fiberglass mat and cloth. This was my first 'glass job, so the layers did not go down very smoothly. I ended up with some air pockets, but if you slap enough layers over them, the structure stiffens up enough anyway. Notice the strips of MDF that I added to the right and left sides- this creates an area that I can screw (rather than glue) the front woofer baffle board to, making it removable at any later stage for repairs, upgrades, etc.

Here's the box after the final layer of fiberglass- some areas have 4 layers, others have 5, 6, 7 or more layers - the consequence of using smaller pieces of mat and cloth and overlapping them. There's no definitive answer to how many layers are enough- you'll just know it as you handle the enclosure and feel how stiff it gets with each successive layer.

Some parts of the box still leaked when I filled it up with water, so I made a "milkshake" - 66% Bondo polyester resin, 33% Bondo lightweight body filler. That combination is perfect for pouring into the box and spreading it all around to seal it (tastes good, too!)

Even the milkshake, as good as it tasted, did not seal one final leak- for that, I used Duplicolor Truck Bed Coating (you can see the can below).

The Truck Bed Coating definitely did the trick- I filled it up to the brim with 9.75 gallons of water (that works out to 1.3 cu. ft.) and nothing leaked out!

What a relief- at this point, the fiberglassing portion is over. There is still much to do, but at least there will be no more itching!
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See Part 2 on the next page to see the cutting and attaching of the woofer baffle board, and adding the woofer, of course...

If you have any questions or comments, or wish to buy this one-of-a-kind, rock-solid enclosure for your Lexus SC300 or SC400, please contact me directly at my AOL email address: SOCALPERY