Okay, so I decided to pull one of my subs and replace it with a new amp. To keep the symmetry of my trunk, I'm going to make a nice cover for it out of fiberglass to match the sub box on the opposite side. Since 'glassing is a skill that can often come in handy, I've decided to capture the entire project on film and document it here for all you Niconauts. On with the show.

Let's start with materialsOne container of fiberglass resin (I prefer Bondo brand but pretty much any will do)Fiberglass mattOne small can of BondoSeveral pairs of thin plastic glovesApprox 5 cheap paint brushesPam oven cleanerspray adhesiveMasking tapecontainers to mix resin inscrap pieces of particle board or fiber board3 or so sheets of rough sandpaper (or better yet a palm sized sander)3 or so sheets of 400grit wet/dry sandpaperA Dremel is real helpful maybe even necessary

That's all I can think of. Total cost provided you have the tools is around $50 or so.

Okay, so we'll start by taping up the area you want to fiberglass. It works best if you work from the bottom up as that decreases the chances of the resin seeping through the tape layers as it runs down the sides. Also cover your car well (both inside and out) as anywhere the fiberglass dries, it stays...forever. mine looked like this when i was done.



Prep your first brush by trimming it like the following picture. We're not going to be brushing the resin on so much as we're going to be "poking" it on and pushing it into the corners etc. Then get your matt ready by tearing it into approx 6" by 6" or so pieces. Tear it, don't cut it. It works MUCH better that way. Trust me.



Now liberally spray Pam onto the area you're gonna glass as it acts like a release agent making life much easier when the time comes to remove the hardened glass. Then hit the area with spray adhesive. Which will assist you in the next step which is covering the entire area in one layer of your torn fiberglass matt. The spray adhesive helps it stick vertically once it gets wet and starts picking up weight. When you've done all of that it should look like this;



Now get your gloves on and mix up your first batch of resin. Easy does it. Less is better. I usually cut the bottom out of a couple of plastic 2-liter soda bottles and mix up maybe two inches of resin at a time. It also helps to be as exact as possible when adding the hardener as with too little it can take forever to set (if at all), and with too much you'll find your resin hardening while still in the mixing container. If it starts to gel and harden before you can reasonably apply it you'll find yourself wasting money and your time should you find yourself having to start over. Once it's mixed start brushing/dabbing/poking the resin onto the matt, covering it entirely like this...



As soon as that's done add another layer of matt and then once again, cover it completely with resin like this...



Now it's time kick back for a minute and let it do its thing. It shouldn't take more than an hour. Two at the max. Of course the warmer and sunnier it is the less time it'll take you. Once it's hard go ahead and yank it on out. It might take a bit of muscle but don't be afraid of breaking it. Once this stuff sets it's one tough muvva. So now you should have something like the following pic only not quite as neat because mines been trimmed up and cleaned with my Dremel and a cutoff wheel which is what you want to do next. Oh and the pic's showing mine from the bottom.



Now make a frame for your amp out of your scrap wood. I took my amps width and length measurements and added an eighth of an inch to each so it would give it a nice trimmed look when I was done. It also helps if you have a router and are familiar with its use. Rounded top edges are a nice touch. Since you're even bothering to attempt this I'll assume you have basic woodworking skills so I'll skip the building of the frame. Mine looked like this...



If you'd prefer to use this info for building a custom sub box instead here's where it get's a bit different. First of all instead of two layers of matt like we've been doing, you'll want to use about six. The reason for that is that a 10" or 12" sub can really move some air. Your box needs to be strong and as flex/resonance free as possible to work properly. Also, instead of framing your amp, you'll need to cut out some rings to support your subwoofer. Now, for an amp rack just center your frame on the inside of the fiberglass "back"we made and use hot glue to hold it in place. For a sub box, use dowels to hold the ring far enough away from the fg "back" to allow enough room so the back of the sub has clearance if you know what I mean. Whichever way you're going, once that's done stretch a t-shirt (the more polyester in it the better) tightly across the front using spray adhesive on the back to hold it in place. If we're still on the same page it should now look like this;



Now get you're gloves back on, get some more matt ready and mix up another batch of resin. I should maybe point out that after each phase of applying resin your gloves, brush, and mixing container go into the trash and are replaced. Don't even think about it re-using 'em. It just ain't gonna happen. Believe me. So once you're ready, go ahead and apply a nice layer of resin to the top and sides, add a layer of matt to it, another layer of resin, another layer of matt and one last time, coat the entire thing in resin. It should now look like this...



and after it dries? Like this...



Now take your Dremel with it's cutoff wheel and cut your top opening trimming as perfectly along the wood frame as you can. Then cut an opening in the bottom large enough to fit your amp in there (If you're making a sub box, skip that last step for obvious reasons). The reason we're doing it this way will be obvious later. The idea is to hide all the wiring leaving it nice and neat looking from the front. So now we've basically got this...



Now it's "fun with Bondo" time. Mix up a good batch and spread it on thick enough to cover all the imperfections etc. Once it's dry, shave off the excess and determine whether you need more. Mine took three layers of Bondo before I was satisfied. Here's what it looked like when I was done.



And here's what it looked like after wet sanding it with 400 grit wet/dry paper. Keep it wet and be sure to get out every single divot no matter how small or you WILL see them after painting. It may be necessary to add small bits of Bondo to some to fill them back up level with the rest of the top. I usually just use my finger for that. It's easier that way. Here it is after sanding;



Now on to painting. For some of you this next tip will seem obvious, to others it'll make a world of difference however so here it is; There is a technique to getting a nice finish out of a rattle can and I'm gonna clue youin on it. Shake well, hold it approximately a foot away and....here it is...ALWAYS push the button before the paint contacts the item you're painting and don't release it until AFTER it has passed beyond it completely. In between is a nice steady stroke of moderate spped. So it's push button, move left to right, release button, push button, head back from right to left, release button, push button, back from left to right, release. Overlapping each strokes edge over the previous and always pushing the button before moving the can towards the item and releasing it only after the spray has cleared the other side. Once you get this down you will be amazed at the glossy, drip-free finishes you will produce. I only learned this two years ago and it was like a major revelation. I had never considered spray painting a learned skill before. Boy was I wrong. Here's my frame after the first coat.

And here it is after three coats installed in my trunk...



It's the exact same technique I used to make this sub box on the opposite side of the trunk;



And one last shot; A close up....



I truly hope that this might help some of you thereby justifying the time and effort involved in capturing each step and typing it out. Believe me taking pics isn't easy when your hands are covered in the stickiest substance known to man and this is easily the most I've typed in one sitting in years. I think my finger muscles actually hurt. And considering I haven't written this long of a letter to my mom since moving out of the family home over twenty years ago, if she were ever to stumble across this, I'd be a dead man.

Enjoy, and if you have any questions I'll do my best to answer them in a timely fashion.

Great post

Glyph wrote:Whichever way you're going, once that's done stretch a t-shirt (the more polyester in it the better) tightly across the front using spray adhesive on the back to hold it in place. If we're still on the same page it should now look like this;

I recommend against using spray adhesive to attach your molding cloth. What I've foudn happens is that the Fiberglass resin/hardener causes the adhesive to release/fail.

I'd take a little extra time and use hot glue. I made the spray adhesive mistake before. I spent a good two hours with a grinder trimming off the folds that occured due to the adhesive failing

Excellent point. I guess I should have mentioned that I don't apply the resin far enough around the back to contact the spray adhesive because you're right, it will cause it to release. It might be possible to use a staple gun? I think the problem with hot glue would be that it's not sticky enough to hold the t-shirt very tightly across the front. Never tried it though.

I think the reason the spray adhesive failed on my enclosure is that I had a transition from the MDF rings inwards toward the box. Meanign the Rings were actually bigger then the box.

That meant that I had to adhere the cloth right until the edge of the mold.

In retrospect I bet every method would have failed. LOL.

I just let it harden. Then ground off the spots that popped up. Laid a woven mat of fiberglass over the smaller holes and applied a pretty hot mix of 'glass. Then I'd just fill it in and then lay a larger piece over it to connect the hole completely to the surround area.

Oh, btw, I found a neat way to make faux carbon fiber.

Use black speaker grill cloth! Use woven mat. The black and weaves from the cloth shows through one layer of mat perfectly. Without looking really close you'd think it was carbon fiber.

I don't know if you're into that crap, bbut I thought it looked neat. Then I put a lot more layers on

I don't mean to criticize, but with that sexy fiberglass enclosure I'd go with a better sub.

YOu ever heard of TC Sound

Just as a point of reference their db-500 subs are on a level between the JL Audio W6 and W7 subs. Better then the W6, not quite as good as the W7.

Not too bad IMO considering the 12 is $109. LOL

-brien

Point well taken. I've had that Audiobahn for many years now. It's actually not TOO bad but it's sq does leave something tio be desired. I've really got my heart set on stepping up to a 12" Alpine Type-R. I've heard them and for a 12" it's nice and tight. Quick enough to keep up with double kick drums and boomy as hell when necessary. I'm far from having heard them all. But it's def. one of the best sounding imho that I have heard. It's comparable price wise to that TC on the net (e-bay). That TC sounds interesting but without the chance to hear one first....hmm, don't know.

Also, I'm assuming the db in the model name refers to decibels which means it's geared more towards spl than sq. I strive more towards sq or as I like to call it sql lol. I like it clean and pure sounding...but loud as hell.I checked out their web site tho' and it does look like they make some excellent products for a reasonable price. So does ED (Elemental Designs). Have you heard of them?

Glyph wrote:Also, I'm assuming the db in the model name refers to decibels which means it's geared more towards spl than sq. I strive more towards sq or as I like to call it sql lol.

Nope, doesn't mean that

TC Sound builds the motor structure to be as linear as possible. Meaning distortion free. They also just happen to build them strong as hell. So, they through a suspension on it to handle the long excursions.

So if anything, SQ is first, SPL second

BTW, I've got two of the 12s on the way

Very cool write up! I've been wanting to work with fiberglass lately too... mainly some door pods, a cupholder, and something to house a a/v switch that's sitting inside my armrest.

I've seen a lot of people use foil in their installs too. They'd have a layer of painter's tape and then a layer of foil, or the other way around I forget. How effective is that method of releasing a FG mold?

Love the clean layout of the trunk. Which CDT's are you running? HD's?

Laa methofds will work as long as you cover the carpet.

I usually forget about the Pam and just glass straight to the tape.

It's a bit harder to pull the mold out, but it will come.

Foil works well too.

Also, I recommend Blue Vinyl Tape over regular painter's tape. It has a built in wax that acts as a release agent

I would really recommend getting one of these The fumes from the resin is proved to cause brain damage and also sanding the fiber glass creates millions of glass particles floating in the air which when inhaled will cut your throat and lungs

karmapolice991 wrote:The fumes from the resin is proved to cause brain damage and also sanding the fiber glass creates millions of glass particles floating in the air which when inhaled will cut your throat and lungs

That's all part of the fun

Seriously though, Lay the resin up outside in a well ventilated area.

I always recommend that you use a mask when sanding though. For the reason you mentioned.

Also, a tip: put baby powder on your arms/exposed skin when sanding. This will prevent ~90% of the itching that would normally occur

Thanks for the tips. What about eyewear? Should specific goggles or glasses be used?

And for more info on carbon fiber stuff or on fabrication, I came across this site: http://www.racingcomposites.net/ lots of good reading.

Ive never used eyewear but i guess it couldnt hurt and cheap way to get a mask is to use a bandana or an old t-shirt while sanding its alot more comfortable and works pretty good too

Don't you worry about getting glass in your eyeballs? If it can make its way through your nose, down your throat and cut your lungs, then I'd think it could easily do the same to your eyes. Has anyone heard a case of that happening?

I advise against using a bandana. I read somewhere that even using those cheap disposable paper filter masks while sanding fiberglass can lead to worse problems. It has something to do with the filtering of the larger fiberglass particles and letting the smaller ones through. The smaller glass particles are more likely to stick to the larger ones. Take away the larger glass particles and you end up inhaling air full of the smaller glass particles which can enter your lungs and throat even easier.

Your right I'm going to school for chemistry i shoulda know better Number 1 rule is to always wear eye protection dealing with any chemical.

phuphyter wrote:Don't you worry about getting glass in your eyeballs? If it can make its way through your nose, down your throat and cut your lungs, then I'd think it could easily do the same to your eyes. Has anyone heard a case of that happening?

I advise against using a bandana. I read somewhere that even using those cheap disposable paper filter masks while sanding fiberglass can lead to worse problems. It has something to do with the filtering of the larger fiberglass particles and letting the smaller ones through. The smaller glass particles are more likely to stick to the larger ones. Take away the larger glass particles and you end up inhaling air full of the smaller glass particles which can enter your lungs and throat even easier.

That's the neat thing about our eyeballs! They're coated with a gel/liquid. This protects them.

You should have heard my optomatrist(sp?) gasp when I went staright from work to the appointment a year or two back.

Well, i was working with steel wool. There was rusted steel on my eyeball! LOL.

I asked her if there was any harm to be done. She can basically the only way is if you get a large chunk(like the size of an eyelash) and then you itch/scratch it.

I've never bothered with eye protection for just sanding fiberglass/bondo. Maybe only for cutting it though as that $hit is sharp

Daaaang that's crazy. [insert "the more you know" star here]

Funny you mention having rusted metal in your eye. I was watching TLC last night and Jesse James, the bike builder was talking about having rusted metal in his eye that had to be cut out.

Anyways, i'm actually doing some bondo today.

I've made a full fiberglass box(no pictures until it's done).

I was going to cover it in carpet. But I figured out that carpet seems look horrible no matter how well they are done

So what i'm going to do is sand and then bondo. Sand smooth, blah blah...

For the finish, instead of paint, i'm going to try duplicolor's Roll on Truck Bedliner.

If I can get a descent texture on it it should look pretty good. Much better then my lack of paint skills would produce atleast

Great article. We've forwarded a copy to your mom, just for ducks.

I'm glad to see my write-up is appreciated. But forwarding a copy to my mom seems an odd way of showing it.

phuphyter wrote:Love the clean layout of the trunk. Which CDT's are you running? HD's?

They're the CF 6.5" (Carbon Fiber) with the upgraded silk dome tweeters. They're absolutely incredible and I'd have to recommend them to anyone.

Defiant wrote:Great article. We've forwarded a copy to your mom, just for ducks.

Oh yeah? Wait 'til ya hear what I'm forwarding to your mom.

PoorManQ45 wrote:That's all part of the fun

Agreed. Can't be beat as far as cheap buzzes go

Thanks for all the interest and feedback guys.

Awesome! Thanks for taking the time to write that up.

I gotta give this a shot some day...

pure hotness. lookin real good

Do you have any pictures of how you did the wiring inside the amp rack?

I need to make a rack for two identical amps. It's going to sit on the floor of a station wagon between the back two rows. I've got enough space. I'm just unsure how to do the wiring.

Did you run the wires directly into the rack, or did you put quick connect plugs on the outside of the box?

Coming in late but better late then never I hear! Nice write up Glyph. Working on a single 8" FG box for a Porsche 993 right now. I'll have to post up some photos for this great thread. I have a few more layers to apply still but it's looking pretty good.

Upcoming project is a gauge pod for my drivers side pillar. The "bolt-on" pods look so cheazy. I think it will turn out nice covered in matching vinyl.

I've build FG sub boxes and door panels but have never tried an in-car panel like that. Never had a reason but I'll have to watch for the opportunity, looks very satisfying.

My $.02...I normally staple my base fabric to the enclosure. I usually use either speaker grill cloth or fleece. Fleece soaks up quite a bit of resin and gets pretty stiff by itself which is why I usually use it for enclosures and larger areas. I use the grill cloth for smaller stuff like the gauge pod I will be making shortly. Never thought of an old t-shirt.

Hey glyph: HAve you ever used roll on bedliner on fiberglass?

I used it on mine. What i just noticed is that my fiberglass walls are now flexing when I give them the thumb test! They didn't flex at all when I first built it.

The only thing that has changed is I put bedliner on it. Can you think of any chemicals in the bed liner that would eat the fiberglass?

It was Duplicolor rollon bed liner if that makes a difference.

Interesting about the bed liner. Do you have to mix the bed liner stuff or is it just a can you "paint" on? I've never used it. If it uses a hardener like the fiberglass I wonder if that could soften up the fiberglass until the liner sets.

Anyway, I wanted to post up a couple photos of my current FG project just to add to the thread. This particular box will sit in the back seat of a 1994 Porsche 993 (911 variant) and hold a single 8" driver. This photo is after 3 layers IIRC. Still hav a couple more layers to go.

In case anyone was interested here's a few shots of the completed fiberglass Porsche enclosure I mentioned above.

Is that carpet?

If so that is a kickass job! It looks very clean.

What'd you charge for something like that?