I want to build a sub box for the center compartment in my C5 coupe. I've never done a fiberglass box before and would love all the help and info I can get. Can you guys give me some help?


Lance

 

help with what exactly?

done fiberglass before?

 

Yeah,never done fiberglass before. Any tips or hints? The box won't be seen so I'm not worried about that.

 

First. this stuff is messy and smells pretty bad.

I do my glass work in the yard. If I cant, I do it in the garage, and move it to the yard if it is possible so cut down on odor.
I have plenty of resin drips all over the garage floor. it is like trying to build something using paper towels, and syrup for the glue.

there are 2 types of fiberglass materials.
Mat= which is a mess of fibers kind of pressed into a cloth. good for building up an area.

Cloth= nice weaved cloth, sharp scissors to cut, and hard to do difficult shapes in one piece. Usually have to sand out flaw with this. like doing a corner of a box, and overlapping the inside and outside. it will bow up at the top. there are ways to get it right, but this is usually what happens first time out.

Resin. you can buy it at home depot. you get hardner with it. I use lots of hardener, so you may want to pick up an extra tube... the more you use, the faster it dries. use too little, it dries in 3 months-maybe. Also depends on outside temp. if mixed good IMHO, it will dry in 30 mins. I usually get 5-10 mins on my mixes before it turned into goop then hard.

I would suggest you go out and buy the stuff to try it out in the yard. make something similar to what you want to do. Do it small scale, whatever. this way you will have an idea of how it is to work with this stuff.

You need old clothes you wont mind throwing away (head to toe). rubber gloves. might want a mask(yes if sanding). pants and long sleve shirt. dont get it on your skin. it takes forever to get it off. and once activated, it burns.

as for getting glass to do what you want. you can soak the cloth in the resin and lay it up on what you want to shape. or you can lay the cloth, hold it with tape (use excess cloth), stables... whatever... and brush in some resin. usually the brush strokes will tear apart the cloth once saturated and make a mess. use a dabbing motion with the brush to avoid this. the cloth streches as you work in the resin. if you use a method to lock the clotch down (stables) you will end up with slop when you are done with the resin. you have to plan this into your work.

as for making a box in the car. remove everything in the car. Tarp off everything in/out of the car. I mean everything.
then you can cover the compartment with a release agent of some type. wax paper. I think foil works. seen some pages with duct tape used.
you can then lay in the cloth/resin with the methods I described above. and go slow to slowly build up a platform to work with. once dry and stable enough, pull it out and complete it somewhere else.

it will take plenty of glass to build up strength.

Other methods are make a cardboard mock up of the box and fiberglass right over it.
I have done thin wood, and fiberglass over it.

Then you have the sub speaker itself to deal with. a wood ring and some dowels to get you an angled sub. I think the material used to strech over the top is some blanket material fleece to get a nice arch over an angled sub? I have used old t- shirts. I staple them into the box and ring, and resin that. then I go over all of the T shirt with more glass completely covering it, because the t-shirt becomes very brittle.

Thats about all I can think of for soing this. the rest is on you for the design, construction, and how it all works out.

One last thing, some guys work really clean. They can lay up a perfect box.
I get frustrated working in such a mess, I just clump it up (non cooperate) and let it turn into what ever it is going to be. I work backwards and shape it back to what I want with a power sander, and do a few more passes on it with glass to rebuild what I removed with the sander. I like to think of it as sculpting.
It will frustrate you, no doubt.

 

Good write up and so true,lol. It's too time consuming for me,lol. I have done a couple of side enclosures and I called it quits in the glassing dept.

 

ive had my new car since feb and subs are still in the temp box soley cause i dont wanna glass it due to the mess

 

If the last three posts haven't scared you away already, click here for an illustrated DIY.

 

Thanks guys. I definitely want to give it a try.

 

Lance,
Go to www.caraudiohelp.com. They sell a couple of videos on fabrication that are VERY GOOD. You'll be able to build any kind of an enclosure. Good instructions, material lists, and nice demos. Worth the money. Mike Coletta

 

go for it!
My last fiberglass glass project was on a guitar. I reattached the headstock to the neck after all other wood glue attempts failed. it is currently hanging on the wall by the headstock.

 

If you take pride in doing some of your own work and like to do new things, jump right in! I built an enclosure for my '02 Z-28 and I never had done a bit of fiber glassing before and mine was probably more complicated than what you are doing. It is the only sub enclosure in a Camaro that I know of that did not take out the spare tire and jack nor interfere with Tee-top storage. There was nothing straight or square on it except the ring for the sub itself.

To add to the excellent and hilarious write up provided by the first responder: some people are very sensitive to the smell of the monomer (styrene) so until you know what your reaction is do it out side and/or with excellent ventilation. A cheap organic gas mask may even be advisable. Ditto any fiberglass dust with sanding or handling. Cheap paper painters masks will do fine for that. Some are even sensitive to the dust on their skin so long sleeves and gloves are a must.

I used latex gloves for everything and mixed the resin in medium sized Dixie cups and like the author put in extra hardener to get a 10 to 15 minute hardening time. That way you can get a number of layers done quickly. Once it starts to harden just dump it in the trash. You will make a bigger mess trying to use it up to the last second than just making a new batch.

I also got some LONG tube socks and cut out the toe and used them for work sleeves to protect my arms and keep my work shirt (yeah, I have a dedicated one just for fiber glassing) from getting too stiff.

I found that you need to get the more or less flat surfaces about 3/8" thick to pass the thump test. I could rap any surface on the box and all you got was a dull thump. Any resonance was too much for me. Think a dead hammer on dirt; not a drum!

I really preferred using the cloth over the felt fiberglass. It is thicker, holds more resin and builds thickness faster and then used the felt to get a smoother surface for a final finish but I did not go for a gel-coat finish. I glued interior matching felt cloth on the fiberglass.

Let me know if you have any questions or want any pictures. It was quite an experience and the results were very pleasing to me but it was a messy start until I got the proportions and the technique down.

 

why are you making a fiberglass box? Mdf is much easier, cleaner, cheaper and will sound better than a FG box

I only make FG boxes when mdf is not an option

 

If you can fit it in. Or a combination of figerglass and MDF. Sometimes you just can't get enough volume and fit it tight with just MDF.

 

Always gotta be that guy in every thread. Thanks for the help guys.

 

all i can say is it is much harder than it looks and expect failure the first time!

I just did tweeter pods for my Mustang and the first one was a nightmare and looked terrible...the second one was much better.

 

I did custom car stereos for 15 years, it's not that difficult (just time consuming). If your going to make it in the center compartment you can line the inside of the compartment with tinfoil, then make your first layer on the inside, and then take it out and work on it outside of the car. Once you have the shell made you can add a frame on the inside and start fiberglassing it in, then add the top and fiberglass it in or make a screw down top (if you build the frame in). You need to see how many cubic inches your sub is going to need because that's going to dictate how big of a sub you can use. I've had good luck with Kicker L5's due to the lower power requirment, the enclosure can be smaller, and the square sub gives you a little more bang for your buck. I've made countless custom kick panels out of fiberglass and they look just like factory. You should check out Sounddomain.com, they have more info than you'll ever need. Take your time on the enclosure because if it leaks or flexes you'll lose spl.

 

Another thing you can do for the initial shell is use fleece instead of the fiberglass matting. If you soak the fleece with resin it'll give you a nice thick shell to start with. Don't worry about the top edges at first because you can just cut them down with a grinder and disc to get the basic shape down. Like one of the other posters said, make sure you cover everything before you start because if you get resign on it, you won't be getting it off.

 

Hey Lamce
I had Jason built me a box and then had a custom top and sid ecompartment covers made. The top of my sub box was made in 1/8th inch plastic and then done in the black hydro carbon finish.
It loookes awesome in the car. Just another option for you

 

That does look really good. I really want to go with the carpet to match the interior. Going for as stock a look as I can get.

 

you should have the top done in leather to match your new seats.