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Hi all. So this is my 4th fiberglass project and I wanted to share. There is much speculation on fiberglass as many people don't know how to work with it, how to create the mold, how to get that disgusting smell out of your car (or prevent it in the first place). I hope to be able to answer all your questions.
Right now I'm in the build phase. This is my winter project so I hope to update this post regularly as the system comes to light. My car is a 2011 Acura TL SH-AWD with tech pkg. My plans are to remove the stock sub, dynamat (with the generic brand) the entire trunk and rear deck, add two JL Audio 10W7-AE subs, add a JL Clean-Sweep prior to the factory amplifier, run a HD-1200 amp, upgrade alternator and big three, and hopefully get the install done in a few months. I have been tinkering with DIY car audio for about 15 years now, I have the MCEP book that I use to reference, but have never taken the test. All my experience is from living, messing up, and learning. I don't mess up too much anymore so here's to all those who think they can't do it ... yes you can, but fiberglass takes time and patience. So here it is .....
My first build I used the masking tape / tin foil / garbage bag method, but after you let the fiberglass sit and dry in the trunk, even in daylight with all the windows open ... your ride stinks like resin, I've never been able to find a way around this .... until now. I built the shell out of 3/8" balsam wooden dowels. You can find them at Lowe's or Home Depot ... or probably any other bigger hardware store.
This part of the trunk is curved, so I simply "stacked" the dowels on top of each other then hot glued them. A multi setting glue gun works best.
Just building the shell out. Notice where the cover for the spare tire is ... the finished product will have a nice gap allowing me full use of the tire well and ample storage still.
Just laid some junk mail down to collect glue drippings, they serve no purpose in the build of the box itself.
Took it out to make it easier to build. Will keep putting in and out of car everyday to ensure it fits. You will want to leave a good 3/4" to a 1" gap on all sides, top, and bottom because as you add layers of fiberglass the thickness will get bigger and bigger, just FYI.
Building around that one part sticking down was a pain ... keep scrolling, all it is is measurements and hot glue. I did get them too close so the nice thing about hot glue is just turn the gun on high and press it against your "welds" and they break apart nicely.
Notice the gap for that piece above?
Fit test .....
Building "out" the next portion
Fit test failed, box is too wide. It won't fit after I glass the box
See .....
My view when I open the trunk, I still have tons of space. There is about a 1.5 inch gap between the bottom of the box and the space access thanks to the ridiculous shape of the sides of the trunk. It worked to my favor
Ok so notice the long dowel rod, that will back up (about an inch away) from the annoying part hanging down. From there I'm just going to build a little "pocket" in the box.
The box is hard to see but it's there, I got carried away building it and forgot to snap a couple pics. The last portion of the box is building it up to the roof of the trunk. I want to create a look of a wall with two massive subs when it is finished.
This is the bottom of the box, when you buy material to wrap it, you want it to stretch. I've found that fleece works best. It can stretch to great lengths without tearing. I bought 3 yards at Hobby Lobby for $17 on sale and it was more than enough to wrap the entire box. When stapling it into the dowels, make sure the staples go all the way in. Otherwise when you add the fiberglass, small raised bumps (like a staple) with create air pockets. Air pockets weaken the box and are bad. If you get pockets you'll have to sand them out. If you get many of them like I still do sometimes, just position the box so the holes are facing directly up (with gravity), then mix another batch of resin and simply fill in the holes. Allow it to dry and problem solved. It's not the correct way but the resin is liquid and gravity will cause it to "pool" in the air pockets. You might have to sand the fiberglass down to expose the pockets but unless you love sanding and creating massive amounts of dust, just expose the holes and fill em up. If you go this route use some extra hardener to speed the process. Now would be a good time to mention when sanding fiberglass to wear safety glasses and most importantly a respirator designed for small particulates. You can get these at Lowe's or Home Depot also in the paint section. Resin and fiberglass will be in the paint section, usually on the lower shelf or floor, and glue guns and sticks can be found by hardware.
Obviously the back of the box. Notice the nice square pocket for that piece sticking down. In the next few pics you'll see I couldn't staple the fleece to the outside of the square as my staple gun wouldn't fit, so I just stapled it to the inside of the box. I'll have some holes to fill in but they are easy. If you get holes, tape them with painters tape then add fiberglass flakes and resin from the other side.
Staple anywhere you have a dowel to help shape the box, once you add a coat of resin, there is no more shaping!
The box is upside down, just showing how I covered up the pocket ...
View from the back of the box. Notice the dowel rod in the square. This will create small holes where it comes in and out. I ended up just putting hot glue over the holes then resin with fiberglass flake on top of it because I lost my tape and Lowe's was closed already lol.
Finished, ready for resin ...
Nope not yet ... I put this pic in here to save all you noobs a huge headache . It's hard to see but do you see how the fleece is kind of crinkled in the corner, almost as if there's a ripple? Well, indeed there is a ripple, and ESPECIALLY for the first coating of resin and fiberglass, YOU DON'T WANT THIS. This is your mold, so unless you want your box to be rippled, re-staple it!!! once you coat this with resin, if you're not happy with the shape, you get to do lots of sanding OR cut it out and redo .... which still requires lots of sanding because now you won't have a smooth surface where the two areas join anyways. I take shortcuts here and there but don't take a shortcut here, make sure all your fleece is pulled taught for your first layer.
All in the paint section. Buy the cheap brushes. These cost me 98 cents a piece. When applying fiberglass, you don't want to "paint" it but rather "dab" it. Dabbing it get's air bubbles out. If you "paint" the resin on, unless you secured the fiberglass somehow, it will move on you and create headaches for you. All of this can be found in the paint section. Also notice I'm using fiberglass cloth. They sell fiberglass mat also, I've just found the cloth to be easier to work with and less messy. The mat is easier to shape with though. The cloth is stronger in the end ... each has pros and cons, I just like working with the cloth, to each their own.
Bottom ...
Side. Note the texture after I added the resin. This is because I'm adding it directly to the fleece just to help shape the box. This is the longer and harder way. Really there's not much need but I guess I'm just OCD like that. You can cut the fiberglass and lay it over the fleece and resin both of them together and there is much less sanding involved
Top ... notice the dust. I've already sanded the edges in preparation for wrapping them with the cloth. The smoother the surface is before you put extra layers on ... the less of a headache it is. Remember though, fiberglass takes time and patience. If you mess up, take a step back and take a deep breath. Fix your mistakes instead of trying to go the lazy route. Fiberglass is unforgiving once it dries. The smoother the better.
Notice the inside of the box is untouched fleece, you'll want to put fiberglass over all the interior sides also. This not only makes the box stronger but also gives the bass something to bounce off of when the subs hit. If you leave the inside looking "pretty" the fleece will absorb some of the frequency of the subs. You want a nice hard and solid surface especially inside for the subs to operate efficiently.
In the coming pictures, I used 1/4 inch dowels and glued them all over the inside. This acts as an extra skeleton and makes the box that much stronger. If possible, only glue them at the tips, not down the entire rod. If you have a gap under the 1/4" dowel, that's good. Use the brush and dab the fiberglass under it as best as possible and try to get all air bubbles out. Once the glass completely hardens, if it completely surrounds the rods, your box will be that much more solid. I let my resin dry at least 12 hours before moving on to another section. Slow and steady, but it will be strong.
Bottom ... well sanded too.
Side ...
Other side ... got some air bubbles on this one. I'll have to sand this one down .
See the 1/4" dowels now?
I circled the discoloration here. Because my box is oddly shaped, when I walk away and come back 12 hours later, this is what I find. This is caused by all the resin dripping down to the low point due to gravity. There is fiberglass mat under here so I'm not worried about it, if anything it just makes it that much more solid. This is a interior side, side being the key. This is the part that sticks out the most so when the box was on its side drying with the resin running into that low point, that far side is just super strong now.
Other side, just needs some light sanding and some dowel rods and I'll put a coat on. The resin again pooled where gravity was leading it to. The box is upside down right here so this just happens to be the top lip.
See the circled part, I had extra resin after doing the top side interior, so I laid some mat down real quick before the resin started to clump and dry and poured it into this small area. I'm now able to put almost all my body weight on the back of the box without it flexing. Almost ready to mount the rings and finish the front.
That's all I have done for now. After 3-5 coats on the outside, there's really no need to add more unless you just like sanding . I'm reinforcing this box from the inside with multiple layers on the inside. I could care less how the inside looks as long as there aren't any jagged edges that might harm the sub.
Some tools that will help tremendously are an oscillating saw with a carbide blade for cutting the fiberglass once it hardens and protruding staples, a rasp sander for the really big drops of resin or fiberglass mat, I have a disc sander for large portions of the box, and if you're making your own speaker rings, a router with appropriate bits. I have a router but I ordered my rings custom made off eBay. I'm almost ready to start mounting them. Any questions just ask, I'll answer them the best I can!
Ok, I've been working on the box here and there for the last month and here are more pics! I did finish the rest of the interior of the box then started here.
This is how I measured the volume. I don't care for packing peanuts because there is too much air space between them. Yes ... peanuts is less messy, but it costs money and can lead up to a good cubic foot of error in your box. With finely shredded paper, I have a pretty solid idea down to about 2 or 3 liters of air space. Don't forget to add the amount of air the backside and magnet of your sub(s) will displace! You have to add this into the specs of your box. As for where I got all this paper you ask? It's about 2 months of junk mail. Who ever said junk mail wasn't good for something right!
This is my shredder. Cost $100 at Target. It's a beast, I've had it for quite some time. I just lubricate the blades with clipper oil (that barbers use) about every month. I do shred all personal things just as a precaution, but never any problems and it lasts.
That line on the top of the box, that's the line I made with the oscillating saw with the fiberglass blade on it. You can cut it with a jig saw too but man, this oscillating saw I bought while building this is absolutely amazing. The cut is so smooth you can run your finger down it with no troubles. I did have to use the jig for the places there were the bigger wooden dowels like in the corners, but I used the oscillating to get through the fiberglass first.
Smooth as butter!
The first support leg for the sub ring, pressed on with hot glue on high setting. Just place a nice sized drop on the box and press the dowel on. They were obviously pre-measured ....
The top support of the left ring ...
The completed front end. I chose to put the subs side by side because I wasn't sure if the annoying square block in the arrow would hinder the huge magnet on the back of the W7 subs. Looking back now in retrospect, I think it will sound great as the subs are pretty much directly behind the driver seat ... in the trunk but still, because of the angle of the box, the subs face directly back with no angle, the sound should bounce back perfectly.
Don't flame me too hard for the leopard print, it was on sale at Hobby Lobby for $6 a yard. It's just getting covered anyways. Not trying to buy $15 a yard fleece only to glass it over ... fleece is fleece ...
First coating of glass. I just used an entire pack of fiberglass mat and placed it over the box and it fit perfectly. Cut and dress the corners then glass it. I worked so well I didn't even have to dab the resin on, I was actually able to paint it on without the mat jumbling up.
Fast forward to the third coat. I am sanding the dimpled spots between each layer. It's turning out to be amazing. I should note that when attaching the fleece, it takes some elbow grease to staple it into the existing fiberglass. Try to staple as close to the edge as possible then drape the mat a good 3 to 4 inches past the edge. This will make it strong and less likely to create a leak in the future.
About to put the 5th and final layer of glass on! I'm sooo ready to be done working with the fiberglass!
Final layer complete!
Notice how far down the side of the box I went with the mat. The front of this box is super strong!
Top side. You can see where the mat stops, I just had some extra resin with the final coat and filled in a few dimples. Last things to do is sand it smooth. I might use Bondo to fill in some dimples to make it super smooth. Yes, you can get this at Lowe's also, right next to the resin. I also will pour a bunch of resin inside the box and lay it face down and let gravity do it's job and completely cover the fleece inside since it is untouched. It will also run into the corners just in case there's a leak in them (which is where a leak will usually occur). All the fleece on the interior of the box will then be covered. Then I think I'll let the audio shop carpet it. Too messy for me. I've done it but they do it better, especially with all the angles.
All in all, a little over 4 gallons in resin and probably 15 mats.
I'll post more as it nears completion. Maybe after it's carpeted. Yes it was time consuming but again, anyone can do this, it just takes patience. It's gratifying knowing I did it myself too. Any questions don't hesitate to ask!
Also on the headlights, I plan on taking the lens off a old set and swapping them over while I have em open for the new (used) diffusers I got from Rockstar.
I've waited way too long for This hahaha
So I finally got around to ordering the Asin Kit. Now it's time for MX, have a bunch of other parts on order as well.
I finished the box back in 2016 but cut the front off and replaced it with three JL Audio 10 W6 AE subs with three 600/1 amps. The system sounded amazing and was super clean and clear, but I couldn't "feel" the bass. Don't get me wrong, I had a good back massage but it just wasn't what I wanted. My brother bought the setup off me and I am in the process of building another setup. Again, I simply just cut the front of the box off so I have my back mold saved. I am in Alaska working the winter season but hope to build a box that will house two Kicker solobaric 15 L7 subs at 2 ohm. The fitting will be tight but I hope it will be worth it. I've been a JL Audio fan for 20 years and still am, but it comes down to air movement for me. With three 10s, I had a surface area of about 230in^2. Two 15 solobaric will give me a surface area of about 450in^2. I'm not certain if I put it in the above post or not but I have a Mechman 240 amp alternator in the car with the big three upgrade, as well as sound deadener lining the entire trunk, under the spare, and trunk lid, under the rear seats, entire floorboard including front seats, and front doors. I only have the rear doors to deaden. I had a small rattle in the side mirrors but corrected that issue by putting silicone in the crack. I cant fold my mirrors in now, but honestly have never had to so it doesn't bother me. I also have a small vibration in my right rear tail light which I will address after the 15s are installed.
01-15-2016, 08:38 PM
. It's hard to see but do you see how the fleece is kind of crinkled in the corner, almost as if there's a ripple? Well, indeed there is a ripple, and ESPECIALLY for the first coating of resin and fiberglass, YOU DON'T WANT THIS. This is your mold, so unless you want your box to be rippled, re-staple it!!! once you coat this with resin, if you're not happy with the shape, you get to do lots of sanding OR cut it out and redo .... which still requires lots of sanding because now you won't have a smooth surface where the two areas join anyways. I take shortcuts here and there but don't take a shortcut here, make sure all your fleece is pulled taught for your first layer.
.
. I'm reinforcing this box from the inside with multiple layers on the inside. I could care less how the inside looks as long as there aren't any jagged edges that might harm the sub. 
