Worklog: Fiberglass sub box's

**SexySamSam** · 11-08-2006, 11:30 PM

Okie dokie, Heres the story. My Buddy Samuel, Yes he has the same name as me, Has a 93' Honda Prelude. He origanly Had a 4.7cb foot box in the trunk with two pheonix gold 12's DVC. He's putting the car in his garage for the winter because a canadian winter is no place for a import. So we got to thinking what can we do to the car during the winter. We decided to make some fiberglass box's so he can have a trunk back. We did some research on the net and read every worklog on this site of previous people who have made some. (mp3car in the sweetest site ever) We got all the supplies needed to do so, thanks to Sam's mom who works at home hardware so we got everything for price so it's like half price.

This is the old box

They will be built in the corners right by the tail lights facing to the front on the car slightly

We lucked out when it comes to the speaker rings, our school has a CNC machine that they let kids use for personal projects. Sam drew up the rings in autocad and the next day got them cut.

http://video.google.ca/videoplay?doc...=speaker+rings
Heres a video of the CNC machine at work

They came out perfect

Today we got the supplies and had some spare time so we went to work.

Thats me

Thats Sam

We taped off the area with about 3 layers on masking tape so that the resin won't soak into the carpet. We took a little trip to Wal-Mart to buy some elmers spray adhesive and a **** load of fleece.

Sam's cat decide he want to help by laying right in the way when we were trying to get the damn fleece.

We then covered all the masking tape in glue and then applied the fleece so that it will take the shape of the car.

We were going to start covering the fleece in resin today so that we can apply the other layers on that but it was getting late, who new it took so long to cover hald a trunk in three layers on masking tape. We are going to start fibreglassing on friday after school, we will update that night.

**megalomania** · 11-09-2006, 01:03 AM

EEEEEEEEEEEEEK!!

STOP RIGHT THERE!

There's no reason for you to bother laying down the fleece like that, in fact don't even bother with the fleece. Throw it in the trash, and go down to your nearest walmart and buy the thinnest spandex you can find. As well as that it's not necessary to lay anything like fleece down when you just need a piece to fit the contours of your trunk. You've already got a mold so use it your advantage and lay the fiberglass down over the taped up and covered carpet. You'll get a perfect fit that's much stronger than some resin soaked fleece.

Order up some different grades of fiberglass. I don't know how many curves your planning on doing, but if it's anything complex don't plan on being able to use you typical 6 oz. fiberglass weave on it. You'll want something more or less around 2 oz. So start off with 2 oz. 3 oz. 4 oz. 5 oz. and your garden variety 6 oz. Take thread fill into consideration and move from your heaviest fiberglass to your thinnest before your final layer, and you'll minimize filler work.

Remember to use weave fiberglass on any part with curves, and for the more complex curves go to a lighter grade of fiberglass.

For the very bottom of the subwoofer box you could get away with using matte fiberglass (looks like interlaced shards of glass) since it is a fery flat surface. In fact I'd more then likely recommend you use matte fiberglass for the bottom since it's such a flat surface, bot for the sides of the box be sure to use weave fiberglass.

One more thing to keep in mind would be to use multiple layers of fiberglass for strength. In a sub box you want strength, and you simply can't rely on resin soaked fleece for strength. Lay down a thin layer of spandex and cover it up in a resin for your shape, and then move straight up to multiple layers of fiberglass. Make sure you lay down multiple layers of fiberglass!!

The only other tip I could give you would be to go down to your nearest hobbystore and buy some cyanoacrylate glue and kicker. Use it to secure your spandex to the wood frame. There's no point in covering up staple holes when staples arent necessary.

**Shadow** · 11-09-2006, 08:18 AM

buy the thinnest spandex you can find

Spandex is mostly lycra which is damn near liquid resistant which makes it horrible for soaking up resin. One layer of fleece is as strong as 3 layers of mat.

I used a wool moving blanket for an enclosure once. I could drive over the mold with a car it was so strong

**LaxPlaya8513** · 11-09-2006, 09:48 AM

i generally don't use a mold for the inner area. Just fiberglass matting torn into pieces and resin layering them little by little. Then reinforce for about 4-5 layers or until it reaches a fairly strong point. Then taking the rings i mount them using dowels and pull fleece over that...but for the molding to car portion i don't use fleece...

**SexySamSam** · 11-09-2006, 11:51 AM

We are doing it pretty much exactly like you did. We're using fleece for the first layer because we read you can and we have 2 days for it to dry then we will put multpiy more layers of matte on.

**Dennis5587** · 11-09-2006, 02:04 PM

yeah, but why bother?

why not just tape, tin foil, then fiberglass over that? After 2-3 layers you can take it out and work on it from there... or can you not get it out because the trunk opening is too small?

**RedGTiVR6** · 11-09-2006, 02:12 PM

This is what we did to make our kicks:

Tape > Seran wrap (with the spray glue to hold it in place) > tin foil (more spray glue) > Mat

We didn't use mat, we used DynaGlass (or a similar named product in your area).

This gave us all the strength we needed so that when we pulled it out we didn't have to worry about it twisting and contorting so it wouldn't fit back in right.

I see where y'all are going with the fleece, but not needed at this point, use it when it comes time to get the shape from the sub ring back to the tub you've just made.

btw - props for giving this a go! I think you'll find it quite addicting, and no, I'm not just talking about the fumes either.

**comet28024** · 11-09-2006, 02:27 PM

Everyone uses fleece in this forum for subwoofers, but when I did my 6x9's in my volvo I made the enclosure out of believe it or not pantyhose. They hold resin pretty well and are really cheap. Also, you can form just about any shapes out of them you want. Anyone else tried this?

**RedGTiVR6** · 11-09-2006, 02:33 PM

for something small, light weight, and not needed to be extremely stiff, they work well. However, they don't provide the best strength overall. They hold next to no resin and will give pretty quickly.