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And so it begins
6/04/2005
I began the project with my friend Paul, he was building
an enclosure that molds to the side of his trunk for two 8"
woofers. We learned a lot through failure on his project as well.
It is difficult to get the resin soaked matting to stick to the
walls of the car. We found that if we cut the matting into smaller
strips, and use small amounts of resin we could get the shape without
it falling apart. |
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Here is my trunk lined with tinfoil
and ready for the first layer of fiberglass matting. |
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Preparing for the first attempt at
fiberglassing.
We laid out the materials on a piece of furniture
someone just happened to be throwing away next door. You make a
mess so make sure you lay down plastic if you care about your work
surface. |
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Mixing resin and hardener is something
that you will have to get a feel for. It is difficult to measure
out several hundred drops for multiple ounces of resin, so you
end up guesstimating - which at first had several outcomes. The
worst situation I have found is when you don't put enough hardener
in and your project stays wet for days. |
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Painting on the resin for the
first layer of matting inside the trunk. |
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Prepping a single piece of matting
for the second layer by cutting in the right places so that the
matting can fold over itself.
More cuts were necessary than this picture shows. |
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This is the first dried layer of
glass in the trunk of my supra. |
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7/08/2005
This is the completed bottom mold with the finished
sub ring installed. 3 layers of glass and 4 layers of resin were
used. I learned a lot from this process: for example it is important
to paint the surface you are laying the matting down on with resin
before you lay it down, this helps the matting stick better, resulting
in a smoother surface with less air pockets.
I had to use tools to grind the air pockets down so
that I could reinforce the walls with matting and more resin. It
was just more work that could have been avoided, and was on the
top half of the project. |
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This clearly shows the layers of
the joined sub rings. I made sure to rough up the surfaces before
adhering them together with liquid nails. Liquid nails is great
for gluing MDF (Fiberboard) together.
I made sure to pre-drill the holes for the subwoofer
before mounting it using dowels which suspended it at the appropriate
height above the bottom casting. |
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Use T-Nuts and matching hardware
to mount your sub to the finished enclosure. It is important to
hammer these in well, and if I were to do this again I would glue
them in or resin over them when I initially built the rings. I
ended up using resin to reinforce them later on in the finished
project. MDF is not inherently strong and they can easily tear through
it when you tighten the bolts down when mounting the subwoofer.
I would have also used the next smaller diameter mounting
hardware if I were to do this again. The larger size that I chose
conflicted with the rubber on the top side of the sub. |
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This is the fleece that I used to
cover the enclosure. Fleece is popular because it can stretch in
every direction which is necessary, especially with a circular project
such as this.
Note: Liquid Nails works very well
for mounting the sub ring, the hot glue that I tried before it did
not. If you do not have them mounted firmly then it could easily
fall apart when you lay the first layer of glass over the top. This
would result in a huge mess, and you would have to tear it all down
and remount the ring. Mine fell apart with hot glue before I got
to this stage. |
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3M Super 77 Spray Adhesive was
used with great success to tack the fleece under the lip of the
bottom mold. It was strong enough to hold up to the abuse of laying
the first layer of matting and resin. |
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7/08/2005
Here is the covered enclosure in my trunk with cardboard
templates that I constructed with the help of a band saw. The process
of measuring, marking and cutting with the band saw went very smooth.
The band saw is accurate and and kept the cardboard stiff, where
as scissors would have mangled it and made for a sloppy template.
The templates enabled me to make small ajustments
to get up close to the curves of the trunk. I cut the final pieces
out of 1/4" MDF which you will see together later as the sub
floor takes shape. |
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7/26/2005
Rubberized undercoating helps to dampen and seal the
well of the trunk.
I had some rust to contend with here, and used a chemical
I bought at an automotive store to neutralize it and dissolve most
of it. I then sprayed this area with rust-primer and then with the
undercoating.
The result will hopefully quiet the trunk a little. |
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The dried first layer of fiberglass
without mounting tabs.
Mounting tabs were added between the first and second
layers.
1. I put tinfoil in the areas of the trunk where i
wanted to mount the enclosure.
2. I coated the tinfoil with resin and laid down one layer of matting.
3. Placed the enclosure into the wheel well and placed another layer
on the top side of the box and pressed the two pieces together to
sandwich the enclosure between the two pieces. This will become
the mounting tabs, perfectly molded to the contours of the trunk. |
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I used a handheld rotary grinder
with a layered carbon grinding wheel to clean up the edges between
layers for a tight fit to the floor of the supra. I found this cleanup
process to be necessary to keep the top tight with the base. You'll
see how I sealed these two layers together a few pictures down. |
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Here is my sub floor, primed first
and then painted with a thick flat black oil base paint. I felt
it necessary to seal the MDF because if water gets to this material
it can tear it apart pretty easily.
To finish this up I had to pre-drill all the mounting
locations into the board and the car. I then countersunk the holes
for the mounting hardware, and finally installed Felt furniture
tabs which I predrilled and used to suspend the boards above the
floor a tiny bit and provide cushioning from vibration and wear. |
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Here you can see one of the tabs
installed. In this picture the third and final layer of glass was
installed and I had used the same grinding wheel as earlier to clean
up the imperfections in this layer of fiberglass.
The more cleanup work you do now the easier it will
be to correct with body later. |
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I used a different brand of resin
to seal the layers together. It worked out really well, as well
as came out glossy and smooth. I made sure to work out all of the
pockets of air, and made sure all of the resin went into the small
cavities around the edges.
This is why cleanup of this edge was so important
at each stage, it enabled me to get a clean join between halves. |
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8/17/2005
Here you can see the enclosure finalized. It is as
strong as it is going to be with 3 layers of glass and 4 of resin.
You could theoretically mount and install the box now, I wasn't
about to looking like that. |
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This is the enclosure with the
first layer of bondo body-filler applied. |
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8/24/2005
This is after 2 layers of body-filler and one thorough
job of using a wood-filler to fill in the remaining rough spots.
I decided that I wanted to get it in the car before
worrying about making it glassy-smooth just yet. I will do that
later, likely will this winter. For now I cleaned it up well and
painted it flat black. |
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Jump forward a bit and here it
is, mounted firmly to the car and with the sub floor installed.
Everything fit together as tight as it looks and that was my favorite
part. I really wanted something solid that would really be a part
of the car. At this point I knew that I had put everything together
right and it felt great. |
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8/28/2005
This is a picture of the first day of electronics
installation. My friend Luke is helping me complete the task of
running wires and mounting electronics. This was a great day for
me, because as you can see from the dates of progress, this project
has been going on steadily all summer long. |
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7/2010
Here is my setup installed with a 1.5 farad cap, a 900watt Kenwood mono pushing a disguised Alpine Type-R 12. The light colored 4 channel kenwood above it is one i've had since about 98' when I was in highschool and had my first car. I bought the kenwood KAC-746 from my friends older brother and it still works great. It's going to get upgraded eventually to give the Polk/Infinity interior speakers some more volume.
You might be wondering why my sub looks the way it does. It was subjected to water damage due to a season of leaking targa seals! I started by throughly RTVing both sides of the seals, then I cut open the cone and scored the inside of the aluminized voice coil and dropped a few layers of fiberglass cloth over it. It took and has been clean and reliable for the past several years. |
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This is my finished work, I bought a pegboard and 1" dowells and traced out a design with cardboard. It is removable and creates a vented, breathable lightweight floor surface that sits off the amplifiers. Nearly stock look with limited wasted space and increased storage.
Lately performance mods and tuning seem to be taking up most of my time and attention right now and so it's nice to have such a functional truck for the targa to sit into and a stereo in my car with such great sound. I can easily throw a bag or two of golf clubs in it.
I seem to have a reliable source of good condition Bridgestone Runflat 18's from my friends at a BMW dealership, say what you will but they do help give a little more confidence without a spare, plus they are fun to burn off at will, knowing you bought 2 full sets for the car for 100$
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Stuff you’ll need for your fiberglassing project
Fiberglass Cloth
Basically you'll have two choices at any place you go to buy fiberglass, matting and woven.
I've found matting works great for the big work, the heavy duty areas. Like the base of the unit you are building. You'll want to use the woven glass for the finer areas, such as when you are trying to put the final top facing surfaces on, etc. Woven stuff can be more of a pain to work with because it stretches and pulls apart different than the matting does. They are usually about the same price.
Buy a LOT of resin, it is usually about 35$ a gallon and you'll use more than you’ll first realize. You'll spend a lot more if you keep buying quarts. The resin comes with hardener, it is a small clear liquid that you mix with the resin and mix up very well. It takes some practice to learn how to get the mixture right for the curing time that you want. I would recommend playing with it first with some pieces of fiberglass cloth and accustom yourself to how long you have to work. You'll want it curing in 8-12 minutes, and this length of time is determined by the amount of hardener you use. If you use too little you will find that hours will pass and it won't dry... Well it will, sometimes it can take days if you don't use the right mixture, but it will usually always harden up eventually, and this is why absolutely imperative that you mix it up well. You do not want to have to deal with unhardened resin.
You'll need plenty of containers to mix it all up in, disposable plastic pails from a hardware store with graduated markings on the side will be perfect. You can usually get a few uses out of one if you let it harden all the way before mixing up another batch.
Find a bunch of stir sticks and some sort of flexible plastic applicator.
Latex Gloves are a MUST.
Get some thick plastic to throw down on whatever surface you are working on, you WILL make a mess and it is much easier to clean up this way. I used the same plastic for a few weeks and then just tossed it when I was through.
This should get you started.
Thanks for checking out my project. I hope that it might have helped
or inspire you to take on such a project, though it may have discouraged
you from it at the same time. This type of thing is a lot of work and
does cost money. I estimate I spent around 150-200$ on this project in
materials alone, not to mention all the time I put into it after work.
It was a fun learning experience and kept me busy while
my friends were working dinner shifts at the vermont summer resort I used to work at. E-Mail
me at craig@thirtythree.org if you have any questions about this project or if you have questions about the process I couldnt answer here.
