Step 1: Planning

The first thing, as with any major project you are undertaking, is to have a game plan. For the scope of this project, planning will be different for each of you trying to do this. You need to vision what you want, some visions require little work, some require lots of work. For this project, mine requires lots of work because I am molding/building this "entertainment center" to the bottom of the trunk. As part of this, it requires me to cut the spare tire "hump" off the car and make the trunk flat in the middle. If you want to do this project without removing the spare then the job becomes easier.

- Write your idea out
- Measure twice, cut once is the general rule of thumb on projects where one mistake can be costly.
- Budget. Going into this project I had a figure far less than what its costing
- Tools, have em. I'll cover them during the project.
- Patience!!! when working with materials like fiberglass, you need to be patient. Don't rush the project, it will only look like crap. 

Item	Quantity	Merchant	Part #	Unit Price
All Purpose Fiberglass Resin (gallon) *	5	Home Depot	076308201265	$35.97
Fiberglass Hardener	1	Home Depot	076308201265	$4.97
3M "90" Adheasive spray	1	Home Depot	051131981768	$9.97
1.5" Utility Poly Brushes *	10	Home Depot	077089181326	$1.97
2" Blue Painters tape roll	2	Home Depot	051115036835	$6.58
Bondo-Glass	1	Home Depot	076308002725	$13.97
Acetone (Quart)	2	Home Depot	030192018156	$6.96
Vinyl Gloves (10pack)	2	Home Depot	662909011114	$1.98
Fiberglass Mat *	6	Home Depot	076308201296	$6.97
Fiberglass Cloth *	6	Home Depot	076308201289	$6.97
Paint mixing tub's *	3	Home Depopt	084305350534	$1.47
Auto Body Bondo w/hardener	*	*	*	*
Sandpaper (all different grit) *	*	*	*	*
Paint suit or disposable clothing

Step 3: Preparing/Fiberglassing the mold in the trunk

Keeping all the obvious work aside (removing panels, trunk components..etc) in order to make a fiberglass enclosure, you'll need to make the mold. To do this we are going to paint the fiberglass resin onto the car to create the mold.

NOTE: Fiberglass resin is NASTY. This stuff smells, is very sticky and near impossible to get out of clothing, let alone off your hands.

1) Get to the area you need to make the mold and using the Blue painters tape, apply the tape to the entire area. This is what we are going to paint on top of. Take special care to protect the area around where we are fiberglassing (i.e. tape trash bags to your exterior to save the paint). Also mask off an area larger than what you plan on fiberglassing. I assure you, this stuff will drip and get on areas you dont plan on it going. BE clean.

 

Be sure to use lots of tape, cover the area very well. If you are like me, I had to spend a good amount of time washing the plastic panels of Armor All...tape does not stick!

2) Grab a marker and mark off the area that you want to make the subwoofer mold. You will use this as guidelines for when laying the resin.

3) Once everything is taped get yourself some car wax (or spray Pam) and apply it to the blue tape. I didnt do this, I was dumb. What this does is when the fiberglass mold has been made, dried and hard, it allows it to pop out easy. if you dont use anything as a release agent, then the tape will stick to the fiberglass, and the tape is also stuck to the car...good luck getting it out, it took me about 1 hour.

4) Now mix up some fiberglass resin. Fiberglass resin by itself doesnt really get hard...its like a thick tree sap. It gets hard when you mix in the hardener. You want to mix the resin in a paintbucket using the directions. It's something like 1 ounce of resin requires 14 drops of hardener. You don't need to focus on the exact mixture, HOWEVER...too little hardener will just make the resin take much longer to harden, this is ok...but too much hardener will not only cause the resin to harden fast (we are talking like under 4-5min per 3-4ounces, but it can cause the plastic bucket you are using to hold the resin to melt.

The chemical reaction of resin and hardner generate heat....when you are applying the resin, you'll feel the warm heat. During certain phases of my project I mixed more hardener that resin and I could actually burn my hands it was so hot....be careful here.

Once its mixed up, you'll have to act fast...it gets hard quick. Do not mix more than about 32 ounces at a time or your just going to waste resin. Just mix a new batch when your ready.

When its all mixed up, grab a brush and paint a complete layer of just resin on the tape. Be sure to cover the entire area you marked off with the market and go about 2 inches beyond that. You'll trim all that off later. Apply 1coat of just resin and then another coat with fiberglass mat (don't use fiberglass cloth at this point). Lay the fiberglass mat down and paint over it with more resin. You want to really saturate the mat. It will turn completely clear when it has been fully saturated. Keep laying fiberglass mat, be sure to overlap the mat you already put down, until your entire area is covered (again go 2 inches beyond your markings). You want to lay at least 2 layers of the mat down.

Once complete, pack it up for the day. Let it dry for 12-24 hours.

 
Step 4: Remove the mold(s)

Ok, it's been 24 hours since you painted the resin. It should be rock solid, go ahead tap on it easy. It should be hard enough to let you remove the mold. The reason we are removing the mold with only 2 layers of fiberglass is so you can work on the mold outside of the car...its a lot easier trust me! You can turn and rotate the mold to apply fiberglass to the roof of the enclosure without it falling all over the place. If you used wax or PAM between the mold and tape , it should just pop out...if you didnt, go easy and keep on pulling the mold carefully, it will eventually give way and pop out. just be easy, while 2 layers of fiberglass feels hard, it can break easy.

Once the enclosure is out of the car, like before do more fiberglass. Keep applying resin and layers of cloth...this time use mat also. Alternate, one later mat, next cloth. Overall you want your enclosure strong!, most people say about 1/2 inch thick. I find this is about 5-7 layers of mat/cloth. I went through almost 3 gallons doing both sides. Once you get enough layers on them, let it dry again, most likely 24-48 hours to be sure. This is what you should have now:

Both sides with 5-7 Layers of glass. Dried for almost 5 days now


At this point, you can remove any tape that is still stuck to the back of the enclosures. It will be hard to get off (if you didnt use any release agent), but get as much off as you can. I'm still peeling some off, but the underside of your enclosure wont be seen.

Step 5: Cutting the molds

Ok, so  now you have your mold(s), each with 5-7 layers of mat/cloth. It's dried for 24-48 hours. You've removed as much tape from the back as you can. Now take your molds, see how they fit back into the trunk. Nice huh? it should fit in place. Now take your black marker again, and re-draw the area you want to keep/cut out, then take the molds back out of your trunk. You should have something like this:

Drivers side Fiberglass mold re-drawn

Now, learn a lesson from me...the above picture. Do you recall when I said to fiberglass a little bigger than the area you need? Something like 2 inches. You can see that in some areas I went out an extra 2 inches...and in others like 6-12 inches! This really sucked, it made it so hard to cut down to the black lines. The further out to the edge of your mold, it should get thinner in laters, easy to dremel/cut...but the further in you go it was 1/2 thick or so....using a dremel was impossible. I had to use the hack saw! then dremel, and more hack saw. In the end I spent near 5 hours cutting both my molds out.... Ok anyways...You need to cut your mold now. If you did like me, get a hack saw and start cutting, as you get close to the black line, switch over to a dremel (or die grinder) and finish the cut out... this is time cosuming, and also messy!!! Using a dremel turns fiberglass into dust...its like white powder. This stuff if toxic to breath so wear a resporator. Also, make sure you are wearing lots of clothing, cause if you get this on your skin you will be itching for a very long time.

Things to know about getting Fiberglass on your skin:

- Wash fiberglass off your skin with COLD water, not warm water. Fiberglass gets into your pores, this is what causes the itching. Warm water opens your pores, this is bad. Cold water closes your pores.
- Dont use soap at first. If you use soap you are just rubbing in the fiberglass into your skin...just keep rinsing for a bit
- When dealing with the resin itself, you'll find if you get it on your skin its very very very very...<taking breath>....very very very very very hard to get off. The only thing that gets fiberglass resin off you is Acetone, which is also toxic. I couldnt get it off my hands a couple times and decided to use acetone on my skin, BE WARNED THOUGH, this is not a good idea.
- Whats worse than getting Resin on your skin, getting it on your skin with hairs (arm hairs). At this point, if that happens, man up an grow some balls....grab a Gillette razor and shave that area of your arm, you'll thank me.

Ok, so now you've been either using the dremel , or if like me, both the dremel and hacksaw. You should have something like this now (note: You want to round your corners off! This picture was before I rounded the corners off. Also, you will have air bubbles, unless your a pro at doing this. just use the Dremel cutting disc or sanding disc and get rid of the bubbles. Depending on how big the bubble was, you might need to add some resin to fill it in, however, at 1/2 inch thick, you shoudl be fine.

Step 6: MDF Rings

This step I'm going to short change you on. You have 2 choices, either make your own MDF rings or buy them. I choose to buy them, here is why:

- Cheap
- Better Quality
- Accurate dimensions

Ok, so now here is the skinny on MDF rings. The rings are what hold the subwoofer...did I surprise you? There are 2 kinds of rings, flush mount (dual layer) and single layer. The dual layer is what you want, it makes the subwoofer flush with your enclosure. Single layer will make your woofer stick out (ugly). There are plenty of websites that explain how to make your MDF rings, just google around. For me, I hit up ebay and found a seller that makes MDF rings. They say best quality, best accuracy on dimensions and roundness...etc. I bought 2 10inch MDF rings from them and had them in about 1 week. The quality was great and the subs fit awesome! They cost me about $20 for the two. I also hear your local Tweeter will make them for you, not sure on the price though.

Here is a test fitting of the rings when I got them:






and you want to reverse mount them (which I am still considering), here is how they fit:

 
Step 7: Mounting the MDF Rings

I found this step to not only be the most fun step, but also the hardest. There are many things you need to consider when mounting your rings to the box:

- Clearance of the trunk latch
- Roundness of the cover of the box
- Support for the subwoofer

The woofer is going to mount to the ring, duh. Woofers can be heavy, in my case the BA G5's weight almost 35lb each. I assure you that the ring mounted to the box with no support would last all of 20minutes. To fix this, we mount the ring to the box using dowels, then we fiberglass the dowels in place, bonding them to the box. The result should be a ring capable of holding lots of weight (in some cases entire body weight if you want to try standing on it, which I dont recommend, if just heard people that have tested it that way).

First, figure out the general area of where you want your ring. What you need to make sure of is that the ring should be further out, past, all edges of your box. This is so when you pull the fabric over to make the top you have nice curves and everything has a tight fit. Once you found that general area you need to get that ring to stay there, this is where the dowels come into play.

Hit up your local home depot and get some wooden dowels, the thicker the better, but not so thick that you cant mount them to the ring. I think I got 1/2 thick dowel.

Next, hit up your local arts and craft store and pick up a hot glue gun and some sticks of glue.

All you need to do is start cutting dowels and using the hot glue, glue them into place. You should bevel/angle the ends of the dowels so they sit flush with where they connect to the box and where they connect to the ring. The hot glue is just to get the ring in place, DO NOT, i repeat, DO NOT try mounting your woofer to the ring or place any weight on the ring. The glue is just meant to keep the rin in position for the next step.

Also, when adding dowels, add plenty of them to support the weight of the woofer. I put lots on the bottom of the ring. Also the corners of a fiberglass subwoofer box are the strongest. Mount dowels from the corners to the ring. You want to support the weight of your woofer!

Once you have the ring all mounted with glue, test fit the woofer back in your car. Make sure the trunk closes and that you have good clearance depending on how your mounting your sub (normal or inverse). This step can take some time...make sure you spend the time because once you start the next step, your never going to be able to reposition your MDF ring.

Here are a bunch of pictures of my rings mounted with glue:


Here is a test fitment of the boxes back in the VR4:




Step 8: Fiberglass the MDF Rings

Sadly I didnt take any pictures (at least that I can find). Only one, the last picture just above.

Once your happy with the placement of your rings on the dowels, just like Step 3, make up some fiberlgass resin and cut some mat/cloth. You want to fiberglass the dowels. You dont need to cover the entire dowel, just the areas where thye join to the box and join to the ring. This is what is going to give the dowels strength and support. Use a good amount of resin and mat/cloth. Remember, no one is going to see the inside of the box, so dont worry about keeping it to clean.

I'm reposting the picture above...look at the drivers side box, you can see all the dowels have been fiberglassed.

 
Step 9: Covering the front of the enclosure

Ok..so now you've got a box(es) that has the ring(s) in place and the dowels all fiberglassed down. You've let it dry right? How about we fully enclosure this puppy now.

We are going to cover the top of the box with fleece and fiberglass it in place now.

Hit up a local fabric stop. Here in New England, we have a chain called "Jo-Ann Fabrics". Just head in and ask for fleece. They sell it by the yard or something. It's pretty cheap, I got enough fleece to cover like 5 boxes for around $10.00. The color or pattern doesnt matter, so if you want to get fleece with Scooby-Doo images on it, be my guest. I however opted for just plain ole black fleece.

Next, hit up Home Depot (or if you are smart, you've read this whole DIY before buying most of the materials so you only need to make one trip) and get some 3M "90" Adheasive spray. It's located in the same place as the fiberglass supplies. This stuff is STICKY...go ahead, try it on your fingers and then try to figure out how your gonna get it off. It sprays out like silly string.

Ok, get the fleece, and cut it up so that one piece can cover the entire front of the box, leave plenty of fleece, we will trim it off after. Start by spraying the glue on one side of the enclosure. Give it a minute to get all tacky (you dont need to spray the fleece). Once the glue on the side of the enclosure is sticky, stick the fleece on. Press it for a couple seconds until it sticks. Wait like 2 minutes and the fleece should be stuck to the enclsoure nicely. The rest is pretty self explanitory...just pull the fleece over the box tightly! and spray the glue on the box again and stick the fleece to it. You want the fleece to be very tight over the whole top of the box. You also want to leave about 2-3 inches beyond where you bond the fleece to the box. This is for when you start to fiberglass, youll find the glue wants to unstick cause of the resin. Take your time doing this step, you can always unpeel the fleece off and try again. Again, just keep the fleece tight. Once its all glued down, trim the excess fleece off.

Pictures speak best, so here you go:


In the following picture, I still had lots of trimming to do.








Step 10: Fiberglassing the front of the enclosure

How you doing? lots of work huh? You "aint" seen nothing yet.

Ok, time to pull out the resin and mat/cloth again. You want to cover the fleeced area to about the same thickness as the backside of the box.

Start by applying 2 coats of just resin with no mat/cloth to the fleece. during these 2 coats cover even the entire ring center. This is so when working with the box after you dont crack anything by pushing on the cloth in the center of the ring.

Here is just 2 coats of resin:



Next, start laying mat, resin, cloth, resin...etc. You no longer need to glass the center of the ring, HOWEVER, make sure you get enough mat/cloth on the edge of the ring. Depending on your final finish , if your going to carpet the outside, you can be uneven and a little messy (though I strive to be the cleanest), However, if your going to finish the outside with paint, you need to lay your glass with no bubbles and very smoothly...take your time here. This is no different than the first couple steps.

Make sure you lay glass past where the fleece meets the box. you want to enclosure this entire thing. The glue may try to unstick, just take it slow and youll get it. You should be a pro at laying resin by now (make sure to wear respirator!)

Here is about 6 layers of mat/cloth...let it dry!







Step 11: (not really a step) To carpet or paint, that is the question

Ok...here we are, we have come a long way. I consider you my friend, after all we have spent a long time with each other, wouldnt you agree? I've got some good news and bad news though.

Bad news...if you want to carpet the outside of your box, this is where we will pretty much wish each other well and part ways, cause I didnt carpet.

Good News, if you want to paint the outside, then pull up a chair, we still have a long journey ahead of us.

Ok, for those that want to carpet, here is what i suggest. Read a few steps on about how to cut the center of the ring out. I would then sand it down to get rid of all the sharp fiberglass parts and then look for a good tutorial on how to carpet the box. At that point, your done with the project. Read more below on how I will be cuting a hole for the wires and then fiberglass over the wires. You've come to the end of a long journey...congrats! send me pictures of your carpeted enclosure and I'll post them on my site.

Want to paint it huh....here we go.

Step 12: Cutting the hole, sanding, putty, sand, prime, OH MY!

Note: Everything in the coming steps I had access to an autobody shop. You can do this at home, but I will tell you that it will be much harder work. The painting concept will be the same, but the paint job I will do will be way better than if your using spray cans...etc. I recommend getting it to the stage where its ready for primer and hitting up a shop to paint them for you, even (gulp) Maacco

Get yourself some sandpaper. This will be hard to do by hand, so having access to a mouse sander or DA is key.

WARNING, WARNING, WARNING, WARNING, WARNING, WARNING

YOU MUST WEAR YOUR RESPORATOR HERE!!!! Breathing in powdered fiberglass is so harmful to your health.
YOU MUST WEAR LOTS OF CLOTHES HERE!!! Fiberglass powder on your bare skin will irritate you to no extent. Should you get fiberglass on your skin, wash with ONLY COLD WATER. Warm water opens the pores, you dont want that. Cold water doesnt open them. dont use soap and dont rub yourself clean, that only rubs the glass into your skin. Just let the water rinse over you. I learned this the hard way and had to deal for days with itchy skin.

Use something around 120 grit. Something enough to get the enclosure smooth...not baby bottom smooth, but smooth enough where your hands dont hurt when touching the box. Dont worry if you hit air pockets or anything, we will be bondoing the entire outside.  It should look like this:






Next, get yourself a dremel, or better yet, I used a Die Grinder and cut the center out. You need to be very careful as you get close to the edge where the ring is, you dont want to hackup the MDF. Patience here.....but to put it in persepctive, using a dremel woudl take about 1.5 hours to do both my boxes, maybe 2 hours....using a Die Grinder took me about 15min to do both boxes. Also, use some sand paper to help shape the circle, make it look like a circle :)

 
Now for more fun...BONDO! Ok check it out, if you were to just prime and paint this now that it is sanded, you would see all kinds of ripples and holes and bubbles and stuff that doesnt look good. What we need to do now is "shape" the box. We want it to look smooth and with nice round curves when done. We do this by applying, in my case, 2 coats of autobody bondo to the outside of the enclosure(s). Of course each coat should be sanded in-between.

Follow the directions for mixing the auto body bondo and then apply an even, somewhat heavy coat to the entire front of the box. We want to build a nice layer that we can shape nicely. After that coat hardnens (like 15min after you apply it) grab some 80grit and take it down, shaping the curves. You might get to low and start to expose the fiberglass. You dont want to do that. Apply another coat or just apply more bondo where needed. The goal is to have curves and nothing uneven.

Here is my ugly self applying Bondo:







SPORTING MY 3SI T-Shirt, New England Chapter style!

Doing this step takes time, and is dirty. Again, wear resporator when dealing with chemicals.



Pay attention to the edges, keep them nice and straight, small curves...etc. Make it look "proffesional". Take your time, sanding sucks! its tiresome, boring and well, yea it sucks.

Sand using 80grit this entire time

When you have it looking good, get some auto body putty (like bondo but thinner in texture, like muddy water texture). Putty fills in the holes and imperfections, it is also much easier to sand off. Sand the putty with about 140-180grit. Get it smooth, no hole or imperfections...again this takes patience. This will be the last thing you do before primer.

At this point, if you have a spray booth mix some primer up and prime, or take it to a paint shop.







Meanwhile - The floor

One of the reasons why I've removed all of my trunk for this project is because I need to make a new floor in order for this project to work how I want it. If I left the existing floor in the trunk, I would have the floor sitting even with the middle of the enclosures. I wanted a new floor, painted to match the setup.

Problem...the floor has a big hump in the middle of it, where the spare tire goes. So I figured I would cut it out and make the floor flat.

Problem #2...so I cut the hump out with a Air Puncher...only to find that the gas tank itself has that very hump (suck design). However, removing the hump gained me about 4 inches of space.

Once the hump was removed, I just laid tin-foil over the gas tank, and fiberglassed a dome over it. I'll then be laying dynomat all over the trunk.






Solution....build a raised floor that will tuck under the subs and come up over the hump, that can be removed. Remember, everything in this project should be removable.

I picked up some 1/2 MDF and build the floor. I took care to make it level, by adding some MDF under it. Once the floor was in place, out with the blue painters tape and then i started to design the sides and such. Keep in mind, we will be using bondo on it after, thats how we form the best shape. Once the tape is down, just like Step #3, start laying resin and FG mat/cloth. The floor portion doesnt need much cause it has 1/2 thick MDF, but the sides need thickness. You can lay the FG on the underside of the floor after you remove the shell.