How to make a Custom Fiberglass Enclosure(s) for the Mustang

SquirrelNutz154 · 11:15 PM

Alright guys, I'm working on a couple of custom fiberglass enclosures that are made to fit in the sides of the trunk of the mustang. I have a convertible and need the room. One is almost done, it just needs some sanding and painting. The other I just started yesterday. I took some pictures along the way and will make them into a how-to for you here. Be patient...I work a full-time job, so it could take me up to a week and a half to complete.

Before I start, I want to warn anybody thinking of doing this. It is an absolute pain in the ass. I more or less equate it to a swift kick to the crotch. It is NOT cheaper than getting a premade box, even though you're not paying for labor. It is NOT easy to do. It will NOT come out absolutely perfect if its your first time. It is NOT clean. And if you have a big thing against being really itchy, DON'T DO THIS. With that said, if you're crazy about your car like I am, and want to take it to the next step.....proceed.

Disclaimer: I am not a pro. I'm just showing you how I did my set up. Do everything at your own risk, I'm not responsible if you screw up something.

SquirrelNutz154 · 08-08-2004, 11:49 AM

Materials and Costs
(These are what I used and paid for. You might find it cheaper or use less materials. It obviously varies a lot.)

-(4)Fiberglass Mat $6 each
-(2)Fiberglass Cloth $6 each
-Fiberglass Resin (1)128 Fl. oz. $30
(1)32 Fl.oz. $10
hardener included
-between 5 and 10 crappy brushes (they get ruined) $15 or so
-pack of latex gloves $5
-Bondo (1) 7lb 9oz container $40
hardener included
-Plastic spreaders $3
-Sand paper-some heavy, medium, fine grit approsimately $10 total
-MDF 1/2" thick, approximately 2'x4' $5
-tin foil
-packing tape
-Bucket (will get ruined)

My total cost was about $150. Like I said, premade boxes are cheaper. As for fiberglass enclosures, this is definitely a bargain. Having one professionally made is very expensive. You could end up spending more or less, of course.

SquirrelNutz154 · 08-08-2004, 11:58 AM

I've attached some pictures (I hope I did it right) so that you can see what we're making. You can also see the advantage in going fiberglass over the premade box. I could not put anything in my trunk before, but after the fiberglass, I will have a lot more space. Plus, I think it looks nicer. The pictures of the fiberglass in the trunk was before I did a lot of bondo and sanding. The picture of that same box on the ground, a lot smoother and primed will give you a better idea of what the final product will be like.

By the way, I forgot to say this earlier....if you want to make a comment, ask a question, or suggest something, please start another thread or put it elsewhere so we can keep the "lessons" all in order and easier to follow.

SquirrelNutz154 · 08-08-2004, 12:07 PM

Alright, first off, I fitted the fiberglass to the side of the trunk by removing the panels on each side. They pull out very easily, you just need to remove one retainer clip at the top. This allows you to mold the fiberglass to the panel itself, allowing the most volume while saving space.

Now you want to pick which side you want to do first. For this thread I am showing pictures of the left side being made. Lay the panel from the left side on the ground, and begin covering it in tin foil. This keeps the fiberglass off of the panel itself. I use tin foil because it form fits the panel really well, and stays in place. The seams can be covered by packing tape. Many people use cooking spray on the tin foil to make it easier to peel off the fiberglass later, but I think that makes it too slippery.

...Here are pictures of these steps

SquirrelNutz154 · 08-08-2004, 12:12 PM

Now, be sure to be wearing clothes you don't care about. They'll get ruined. PUT ON GLOVES. This is a very big case of do as I say, not as I do. I can't work with gloves on, I liked being able to feel what I'm working on. Fiberglass is extremely itchy and can cut you easily. With that said, I highly recommend wearing some thick latex gloves. If you don't believe me, look at the image I attached. This is my hand covered in fiberglass. It hurt and itched. So, unless you're a dumbass like myself and must use your bare hands, wear some gloves.

Falcon · 08-08-2004, 12:16 PM

sweet thread, looks great. Hopefully someone will get in here that has the power to make that a how to.

SquirrelNutz154 · 08-08-2004, 12:19 PM

Okay, now comes the part where you begin laying the fiberglass on the body piece that is covered in tin foil. For this, I recommend using fiberglass cloth, not mat. The difference between the two is that cloth is strong, but will not conform to curves too well. Fiberglass mat is very easy to conform to curves, but is not strong. Since we have the body panel we can lay the pieces on, we'll use cloth for this.
Take one of the packages of fiberglass cloth. Begin ripping pieces off and laying them on the body panel. Ripping is much better than cutting, as it allows the fibers to mesh better. Continue laying the pieces out until you have completely covered the side of the body panel that faces the inside of the trunk. I used one entire package of cloth on this.

pictures...

SquirrelNutz154 · 08-08-2004, 12:27 PM

Now we need to apply the resin to the cloth to make it hard. Pour a few cups of fiberglass resin into the bucket (you don't need to measure it perfectly....just kinda estimate) The resin will not solidify on its own. You need to add some hardener that is supplied with the resin. Read the directions and mix it accordingly. The more you add, the faster it hardens. I just kind of estimate it, but I have done this before and kind of know how much to do. You definitely don't want to add too much, or you'll have a solid bucket of fiberglass, or add to little and have to wait a week for the damn thing to harden.
Immediately after adding the hardener, mix it up quickly with the brush. Then begin applying the resin/hardener mixture to the cloth itself. Really glob it on, its much better to use too much than to use too little. You do need to do this fast though, and it is a hassle, as the fiberglass begins sticking to the brush, you, and everything else imaginable once that mixture touches it. After you have coated the fiberglass cloth with the resin, try to smooth it out with your hands. If it sticks too much to your hands, spray cooking spray on the gloves, and thatll fix it. Once the cloth is covered and smoothes, just let it dry. If you mixed it correctly, within an hour or so, it should be fairly solid.

SquirrelNutz154 · 08-08-2004, 12:31 PM

Once the piece is completely dry, pull it off of the body piece. Most of the tin foil will come with it, and its a pain in the ass to pull off, but its what you gotta do. This point is where I am at right now. Ill attach some pictures of it at this stage, including one of it next to the other one thats nearly finished. I should be getting more done on it today, and will post picture of that later on. Once again, any comments, question, etc, throw it on another thread or make another one so this thread is clear.

Dom · 08-11-2004, 09:06 PM

Nice guide. If you could get all the pictures and test together and submit it to Brent, I think he would put it up as a guide on the articles page.

Until then this is stickied.

SquirrelNutz154 · 08-11-2004, 11:36 PM

Yeah, I need to get back to work on that. It'll be within a few days. I got a little sidetracked......my good friends at CDC just got me my brand new shaker system and chin spoiler. I need to do some finishing touches on the installation tomorrow, then pics will be up, then ill finish up the sub enclosure.