Well I have written up a little how to for building up a fiberglass box....
How to build your own fiberglass box.
First off measure out the space you have to install the box, it is better to measure twice and build once. There are 2 different ways you can build the bottom of the box. If you want to make it conform with the contours of the car then you will need to lay out plastic to protect the interior from resin and then hand lay 3 layers of resin and fiberglass mat to the plastic. Let it cure before removing it from the car. The other way is to use wood for a flat bottom, 3/4 “ MDF is a good choice.
Second you will have to cut out rings to mount the subs into. Make those out of MDF as well and sand them smooth.
Next mount the rings in a fashion that you want. The more curves you have the more sanding you are going to have to do, so keep that in mind. For mounting the rings I used 2” strips of wood to make legs and then glued and screwed it all in place.
Next take a fabric that stretches both ways to cover the whole thing ( I used a nylon material ) and staple it in place ( I used a staple gun ). Mix up some resin and brush it on and let it cure.
Once it is cured well, start cutting fiberglass matting into roughly 6” by 6” pieces and cover the box with the matting and resin. Do this about 7-10 times to build up a good thickness and make sure you let it cure between coats and sand down any high spots when needed to help keep the box fairly smooth. When you are on the 2nd or 3rd coat you can cut out the areas where the subs will mount where as there will be no need to build up the fiberglass where you won’t need it. Once you get the glass built up enough, then move on to the next step.
Now you take a fiberglass reinforced body filler and cover the entire box. This makes it easier to sand smooth, especially if you plan on painting the box. Once you get that sanded fairly smooth move on.
For the last coat of material I used a real thin skim of Bondo to make all the curves real smooth. Try not to use a lot of Bondo. If the fiberglass reinforced filler was used right then you should not need much Bondo. Sand it all smooth with 80 grit then working your way to 220 grit to get rid of all gouges in the material.
Now prime out the box with a good sandable primer and then wet sand it with 800 grit to make it real smooth and then you are ready for paint.
The whole job will take a long time, but if you are not in a rush and go slow with it, you can have real good results, and save a lot of money at the same time. I spent roughly $120 on materials for mine.
If you have any questions, please feel free to ask me, and I will try to answer all of them.
Good luck and happy modding....
____________________ 2001 Focus Street Edition, tons of mods but I will never be done....
That's an awesome how-to!! Great pictures and thorough explanation! If I didn't have subs in my car already , I would definatly consider this, theres never too much bass for me
____________________
It's not about what you have under the hood, it's about who you have behind the wheel...
This is the exact "HOW TO" i used !! Im totally stoked on how my box came out, and the sound is better than the carpet'd box i bought with the subs. Thanks for the How to !!! Here is a pic in case your curious on how it came out
____________________ "They wanna fingerprint me, and give me some years, they only get one finger while im shifting gears" - Looda
That looks hott! I want to do this when i can afford to get a new system, but don't wanna loose trunk space. a friend showed me how his sub was backed up/over against his wheel hub so that his trunk was still wide open. (so it was positioned between the wheel hump and the hatch).
I'd wanna do this one on either side, but that covers the whole trunk from hatch to seat, but only over the wheel wells, and has them angled so they point back at a bit of an angle. know what i mean?
think that's doable guys?
____________________ 01 ZX3 in French Blue
Fog Light Mod // Intermittent Wipers // Clear Side Markers // Back 3 Tinted // Painted HVAC vents (courtesy of MustFCS) // De-badged // Eurostar LED Tail lights // SilverStar Head light bulbs // Upper Grill Light Delete
mustfcs wrote: Well I have written up a little how to for building up a fiberglass box....
How to build your own fiberglass box.
First off measure out the space you have to install the box, it is better to measure twice and build once. There are 2 different ways you can build the bottom of the box. If you want to make it conform with the contours of the car then you will need to lay out plastic to protect the interior from resin and then hand lay 3 layers of resin and fiberglass mat to the plastic. Let it cure before removing it from the car. The other way is to use wood for a flat bottom, 3/4 “ MDF is a good choice.
Second you will have to cut out rings to mount the subs into. Make those out of MDF as well and sand them smooth.
Next mount the rings in a fashion that you want. The more curves you have the more sanding you are going to have to do, so keep that in mind. For mounting the rings I used 2” strips of wood to make legs and then glued and screwed it all in place.
Next take a fabric that stretches both ways to cover the whole thing ( I used a nylon material ) and staple it in place ( I used a staple gun ). Mix up some resin and brush it on and let it cure.
Once it is cured well, start cutting fiberglass matting into roughly 6” by 6” pieces and cover the box with the matting and resin. Do this about 7-10 times to build up a good thickness and make sure you let it cure between coats and sand down any high spots when needed to help keep the box fairly smooth. When you are on the 2nd or 3rd coat you can cut out the areas where the subs will mount where as there will be no need to build up the fiberglass where you won’t need it. Once you get the glass built up enough, then move on to the next step.
Now you take a fiberglass reinforced body filler and cover the entire box. This makes it easier to sand smooth, especially if you plan on painting the box. Once you get that sanded fairly smooth move on.
For the last coat of material I used a real thin skim of Bondo to make all the curves real smooth. Try not to use a lot of Bondo. If the fiberglass reinforced filler was used right then you should not need much Bondo. Sand it all smooth with 80 grit then working your way to 220 grit to get rid of all gouges in the material.
Now prime out the box with a good sandable primer and then wet sand it with 800 grit to make it real smooth and then you are ready for paint.
The whole job will take a long time, but if you are not in a rush and go slow with it, you can have real good results, and save a lot of money at the same time. I spent roughly $120 on materials for mine.
If you have any questions, please feel free to ask me, and I will try to answer all of them.
Good luck and happy modding....
hi. i wuz wondering what type of resin did you mix up to cover the fabric. and what type of fabric you used to cover the box... thanks tim
Well....He used fleece, You can also use spandex, polyester or anything stretchy. then thicken it up after the original coat with chopmat form behind. The resin and hardener are not cloth specific.
There are many kinds of resin out there. Polyester resin, etc and many more. Home Depot I thik is polyester. Its a thinner version.
____________________ Captain Morgan and Dr.Pepper are my homies....
About how long would you say it took to sand the whole thing to where it was perfect. You mentioned it took a long time but how long is long? The reason I'm asking is my current box that I had in my Avalanche I think is too big.
It's 19" high, 49" long and the top side or front face (depending how it sits) is 20" It's a pretty generic rectangle box but it worked perfect in the midgate of my truck. I just thought that if I could somehow use this box I could get my system in faster.
You have that program right? I have a 2006 ZX4 4 door and I have (4) 12" subs and I was thinking of putting 2 in the smaller part of the trunk then putting the other 2 by the wheel wells in order to still be able to get at the spare. I also wanted to do something cool with my amp and some neon. I could prob come up with a design but if you wanna give it a crack that would be cool with me. I don't know much about measurements or anything like that so it might not be doable.
