Gonna need some fiberglass help soon...

I want to make a custom enclosure for my subs in my trunk. I have two twelves, and want to make something like:

http://memimage.cardomain.com/member_images/7/web/559000-559999/559749_92_full.jpg

Not quite that far apart though, but it gets the idea across. And I would want the amp behind the enclosure. And if you cant tell in that drawing, both are kind of angled inward.

Only problem is, I have no idea where to start.

Anyone got any resources or tutorials you could link me too? Or wanna to take the time to write one?

Or just any tips on where to start?

Thanks,
Tim

I'll help you out man. I do it the classic way, and avoid the kitty hair.


First you need some polyurethane foam, it can be expensive, so I have a reccomendation. Go to a commercial construction site, and look for some yellow somewhat "hard" foam. To see if it will work, mix up some bondo or epoxy and put it on it, let it cure. Thats the test, and 95% of the time it will work when laying the fiberglass.

Get a bunch of the blocks, take off the backings so its pure foam. Glue them together with bondo until you get a rectangular box the size that you need to carve out of. Take a sawzall or resiprocating saw and cut out the basic shape.

After the basic shape has been formed, start sanding it into a better shape. After the shape is formed cut out the holes for the subs. Try to find some wood circles if you can to place in the holes to insure a perfect fit for your subs.

Now the fun part, mix the fiberglass with the epoxy. I can go through that if you need. And drape it over the foam mold. After it starts to kick (get hard) cut out the circles with a sharp razor. If it starts to pull, let it cure a little more. Then repeat about 5-8 times, depending on the strength.

Theres the basics.

That's pretty much the way it's done... You can get insulating foam from a hardware store, Home Depot should have it in big 4x8 sheets. Get a can or two of 3M spray adhesive, and give it a good liberal coating to glue the sheets together in a stack as needed. The easiest way to get a good rough cut to start with is using a snapoff blade style utility knife, and then working with a coarse grit sandpaper to smooth it out. Getting some of the contours right can be really tricky, especially when you have to make two of them identical.

You'll want to get a block of wood for sanding, a chunk of 1" dowel can be really handy too, and I've used a large softball before to get a nice rounded shape for sanding. It often helps to cut slits in the edges of the sandpaper to get it to fold nicely around the ball.

Don't be afraid to slather more resin on, it'll give you more surface you can sand down, and a lot more margin for error.

Is the foam the easiest way to go? Because I have seen a couple in progress projects on various site where the guy has has built a wooden frame and streteched fabric over it.

That's pretty much the way it's done... You can get insulating foam from a hardware store, Home Depot should have it in big 4x8 sheets. Get a can or two of 3M spray adhesive, and give it a good liberal coating to glue the sheets together in a stack as needed. The easiest way to get a good rough cut to start with is using a snapoff blade style utility knife, and then working with a coarse grit sandpaper to smooth it out. Getting some of the contours right can be really tricky, especially when you have to make two of them identical.

You'll want to get a block of wood for sanding, a chunk of 1" dowel can be really handy too, and I've used a large softball before to get a nice rounded shape for sanding. It often helps to cut slits in the edges of the sandpaper to get it to fold nicely around the ball.

Don't be afraid to slather more resin on, it'll give you more surface you can sand down, and a lot more margin for error.

I believe you are speaking of the blue foam? That foam is a polystyrene foam and does melt when the resin gets chemically hot, or any chemical gets "hot". You will end up laying you fiberglass and it just melting through.

Is the foam the easiest way to go? Because I have seen a couple in progress projects on various site where the guy has has built a wooden frame and streteched fabric over it.

If your good with wood go with shitty hair (kitty hair). Its a hell of a lot easier than the old school fiberglass, thats why I dont like it. What makes it fun if its easy?

If your good with wood go with shitty hair (kitty hair). Its a hell of a lot easier than the old school fiberglass, thats why I dont like it. What makes it fun if its easy?

Either way its totally new to me, so the fun would be learning it, and hopefully doing it right. Anyway, I am trying to keep the price to a minimum, and I can find wood for pretty cheap, and just need to find the chemicals. What would be the chemicals and stuff I would need? Whats this kitty hair you speak of, and how does it work?

I'll explain later Tim, I'm off to work.

Actually, polystyrene is fairly resistant when it comes to heat, unless you're casting a boat hull or something with many weaves of fibre. As long as you coat it with something, it should would out. A friend of mine uses this method, and gives it a spray coat of an acryllic enamel to seal it and make the mold.

I was going to suggest fabbing the wooden box and stretching the material since its your first time(although I've never done it). From what I've seen, it looks just as great while saving time and money. You will also be more likely to match the speaker enclosure.

Build the back of your box with MDF, out out rings for your subs out of MDF, this is just what it sounds like, a ring that your sub fits into and is about 1" wide from inside circle to outside circle. Use scrap peices of wood or what ever and position the rings where you want them, hot glue them in place with scrap peices of wood. Use Fleece to stretch over and stapple to the sides of the box and to the rings. Coat it in fiberglass resin and let dry. Now build up using fiberglass mat about 1/2- 3/4" thick. Dont fiberglass the fleece on the insides of the ring. Use a knife to cut out the fleece on the insides of the rings. Now sand it with an electric sander and smooth with bondo, final sanding by hand. This is alot easyer than trying to do it with foam.

check out www.the12volt.com as well. it's a plethora of knowledge about fiberglassing as well.
i'm wanting to do my own sub box also and have been researching for about 2 months now.

I am in the process of starting a custom composite fabrication shop , I have built many show winning cars that have had completly fiberglassed interiors, plus we specalize in fabrication of custom fiberglass enclosures, as well as custom body parts. all parts can be wraped in vinyl, carpet, or can be layed up in carbon fiber, or platnum carbon fiber (aluminized) or can be painted.. I would be interested in discussing what you want in more detail so that an accurate price can be established.. feel free to email me for more information..I have pictures of previous work that i have done that i can email to you at your decression..

O.K., the audio guy's pissing me off. spam somewhere else, asshole.