So Ive been messing around on my lunch hour at work and decided to dive into fiberglassing a box for my car, its a bit oversized for my current subs but thinking long term I spec'd it for W3's I'm just going to crank up the power and add some jute material to the inside to make up for the air space difference any way here's some pictures it hasn't gone half bad for my first fiberglass box
This is the frame I started with, just made it from scratch as I went

Here's the frame in the car, the entire well was lined with blue tape so I could mold it to the carpet, the rear around the hatch bulge was built with cardboard and tape, attaching to a piece of 3/4 Mdf in the bottom of the well

First layer of fiberglass, a second one was laid over it to make it rigid enough to remove from the car

Here is the rough base, took a bit of work to remove it but it came out perfectly

Outside of the box got another coat of resin to waterproof it, and both rings were mounted at the exact same angle (1st one took about 10 mins, 2nd one took about 2 hours to match it lol the center board was the base for my Plexiglas LED spot

Stretched with zebra fleece and stapled down to get the shape of the top

Nice thick coat of resin on the fleece to harden it (still need to do a layer of glass on the inside the fleece didn't take to the resin in all spots so its a tad weak but still has its form)

And this is where I'm at now, sub holes cut out and all stilts removed, just need that final layer inside and the box itself is done.

If you notice around the entire box I made a 3/4" border so I can cut a trim piece to flush it into the trunk. The center spot is getting the resin soaked fleece cut/ sanded out, a clean piece of zebra fleece will be glued in and a piece of Plexiglas will be mounted on top of it spaced 1/2" up, blank for now until I decide what I want to put on the Plexiglas. LEDs will be tied to the trunk light so its not on all the time. Overall I'm happy with the results, it will sit low enough for me to use my t top bag once again and it will be sealed for great bass response.
Thoughts? Opinions?

 

When you fabricate stuff out of fiberglass like this how well does it hold up over time? I've been wanting to make some custom air-intake boxes and I cant weld... so fiberglass was an option but I am concerned about the durability of those inside the engine compartment. Did you make a mold of cardboard and layer fiberglass on both sides of it? I love ingenuity like this. Great job.

 

It depends on how the glass is laid, in the engine compartment I'd imagine you would need to line it somehow, maybe a rhino liner outside? When you lay the glass it would have to be perfect resin to cloth ratio, no glazed resin look, ideally like the inside of a boat how you can see the fibers but they're hardened, and it would need to be thick, as far as the heat idk about that lol as long as there's no air bubbles and its a good thickness I don't see why it wouldn't work

when creating the base mold I only laid fiberglass inside the box, the outside is fitted to the trunk contours so if I built on the outside it wouldn't fit


And thank you btw

 

good looking setup so far. look forward to seeing how it turns out

 

Subscribed. Looks good so far.

 

Cant wait to see the final outcome

 

lookin good

 

just put the inner layer of resin on the top, gonna let it set then slap it with another top coat overnight

Im kind of torn on how to cover it all, the box and the trim will be done with the same material, i think it would look extremely odd having like the box black and the trim grey or vice versa, you guys think i should jsut go with grey like my interior? give it a flow effect? A buddy of mine said carbon fiber vinyl but....no. Vinyl in general would be a pain to stretch over the entire top

So grey? or any other suggestions?

 

Forgot to post progress, went grey on the box, trim will be the same, I had to stop at this point because my blade slipped and sliced my index finger open and I didn't feel like bleeding all over my hard work

 

here's the finished product, got the subs mounted and white vinyl placed in the center, blue LEDs mounted.

it hits damn hard for W1s, much deeper bass with great response all that's left is building my trim piece when I have time, the lights are also tied to the trunk light so when I pop the hatch they kick on, plexi will be finished soon too so the LEDs aren't so blinding

 

Looks sweet, what is your total time spent on this project so far? I've always wanted to mess around with fiberglass, just haven't done any reading on it yet. Not enough time or space now that I don't have a garage

 

where do you get your resin from?

 

bro you gotta help me make one, i got my box in the backseat and have no room for the ladies time for a trunk box lol, got the dimmensions from the post here on TGO, now gotta go get the wood cut out. or should i go fiber? idk what to doo? but i dont no crap about fiber!

***** very nice though man,

 

Nice box and I like how it sits down lower in the trunk. I just want mine to have a solid cover so i can still use my truck.

 

Oh wow I haven't gotten any emails on this for a while lol our shop uses select products resin but all my resin came from lowes its 3m brand and it comes in a gallon for like 40$, I used 2 gallons and a quart total

Total time spent was about 5 days at work so probably about 8 to 10 hours because of resin dry time, again you can shorten the time by mixing it hotter but if you go too hot it will bubble, crack and lay a weak spot in the box, and it burns like hell and starts smoking

Latex gloves, paint cups and stir sticks (plenty of all 3) are a must, and a good respirator too you will get dizzy quick from the glass and hardener, even outdoors. Honestly ill tell toying the same thing I was told you just do it. Dive in and get to it worst case scenario its junk and you toss it

 

Awesome, Can you send me the dimmensions you used for yours? i like how it came out, and how many layers of tape did you use?

 

There are no real dimensions involved, the wood piece was cut from scratch and I believe I made it 2 inches tall, the rest is just tape and cardboard and fiberglass, total volume wad never measured I just overpowered the subs to accept the enclosure, as gas as layers go I kept going until there was no flex in it, so probably about 6 but I do my layers thin usually

With the cardboard make sure you leave space for the hatch bulge, I went from my frame down to the edge of the carpet at an angle, your cardboard as to be rigid with no holes. Fiberglass is very forgiving so if you mess up it can always be fixed if there is a small hole don't stress about it just hit it on the next coat and pay special attention to it

 

with the carboard outline did you leave it and coat it with the fiberglass?

ok so let me get the steps right:

1: make a outline and put tape-carboard around the area where the box is going to be
2: spreak fiberglass around
3: wait till dry then add another layer
repeat till layers are ok (like 4 layers no?)
4: cut excess layers

and do the same for the top? or am i wrong?

 

Build your top frame
Tape off entire well area
(Optional) cut a piece of mdf board for the bottom of the well and lay it in
Place top frame in the car
Tape bottom edges of frame to existing tape
Use cardboard for the bulge area and tape
Lay down mixed resin
Lay fiberglass over resin and apply more resin to achieve the first layer
Dry
Repeat resin then mat then resin


Before you do any glassing the well should look like it has a tub in it, all the tape and cardboard should be smooth and look like it can hold water pretty much, when you do the glassing leave the cardboard in and let it dry to it you can peel it off last.

When you lay the glass down make sure it isn't soaked with resin it has a perfect look to it, no white spots ( air=weak points) and it should look like the inside of a boat where you can see the strands no glossy resin look

IMPORTANT : between each layer make sure not a single strand is sticking up it will ruin your next layer!! When you apply the resin use the brush tip downward like your basting something to spread the resin out and remove air bubbles

Once the basin is dry and sturdy remove it from the car.

You can either do a flat board across the top or angle it like mine, flat is easier, just sand the strands up on the frame flat and apply the top board on with the sub holes cut
Angled subs require the correct size rings, and stilts. Place the ring how you want and use the stilts to make it sturdy it will have pressure applied to it so if its flimsy it will fall. Take thick fleece and staple it to the center of the box and stretch in all directions until its firm, poke it and there's minimal to no play in it. Soak the crap out of it with resin but dovnot coat the hole for the sub completely, just around the edge so the extra can be cut out coat the outside and inside once the outter layer is dry it is the same as the glass part NO WHITE. Cut your sub holes out and carpet it. You can reference my pics for what I'm taljig about.

Once the top is complete use some resin around the top to base seam so its sealed before you carpet it

 

Where can you get the sub rings at? and Do you know how the cubic feet of the box? Thanks

 

They're easy enough to make with a router and circle cutting jig.

 

Just like al said, I have a template ring I use with the router, trace it and cut it with the jig saw then use the router on it, if you don't have a template you can make a 10' circle and cut carefully and go out about 2 inches and cut the outer portion. You can probably get a car audio shop to make you a set if they do custom work two rings can be banged out in 10 mins.

Ad far ad total volume I never measured it when I was done, didn't have the patience to fiddle with packing peanuts, if my math was right its 1.3 give or take, the variable is the angled portion, didn't account for that in my original design it was a spur of he moment deal, it works great with W1's and will also work for W3's, tad large for the 1's and a tad short for the 3's but that's nothing a bit of polyfill and overpowering can't fix, it pounds lol my wife can hear me coming down the road even without an over bassy song