# Another fiberglass box tutorial..



## dawgdan

Been working on this one for a little while, finally got the page up. Lemme know what you think.

http://www.gadrivers.net/~dwicker/fiberglass.html


----------



## ocuriel

Very nice. That is going to be very helpful for a lot of people.


----------



## dawgdan

Thanks. I have always been a chronic researcher, and I didn't think many of the tutorials out there had enough detail on what to buy and how to use it. I know it's not 56k-friendly, but hopefully it will be of use to some folks out there.


----------



## solacedagony

Awesome tutorial. It makes me feel like I actually have the courage to give it a shot!


----------



## Beau

Please accept my praise and thanks. I will be venturing into fiberglass at some point in the near future. 

Now all I need is your home phone (j/k), so you can tell me how to fix what I've botched.


----------



## Lothar34

Your milkshake is the best.  

j/k
Nice writeup. Please don't take it down ever because I'm sure I'll need it for reference someday.


----------



## dawgdan

It'll be up for as long as my buddy's server is up. Thanks for the props.


----------



## npdang

That is a very nice tutorial... feel free to copy it over here if you want


----------



## Relax

Lothar34 said:


> Your milkshake is the best.
> 
> j/k
> Nice writeup. Please don't take it down ever because I'm sure I'll need it for reference someday.



Just save the site to your harddrive- go to favorites, add it as a favorite and click "make available offline." Or file save as: and then maker sure you have complete webpage as the selected save type.


----------



## FoxPro5

Oh man, perfect timing for me! One of the best tutorials I've ever seen! Thanks for the time spent doing that and posting your work. You know it's done right when the final product just looks like it belongs in the car.


----------



## scott_fx

great tutorial! thanks, i'll be bookmarking this!


----------



## dawgdan

B-Squad said:


> Oh man, perfect timing for me! One of the best tutorials I've ever seen! Thanks for the time spent doing that and posting your work. You know it's done right when the final product just looks like it belongs in the car.


Heh, wow, thanks for the compliments. 

I'm no expert, but I was pretty pleased with the final results. 

FWIW, I can't really stress enough the importance of the Knytex biaxial I used. Every other tutorial I've seen and pretty much every other box out there uses plain chopped strand mat. I used chopped mat on some surfaces for this project.. and I only used it because I had to. Knytex is absolutely superior in every way, except when you're trying to do any upside-down surfaces. I don't have the patience to lay 8-10 layers of chopped mat, and the Knytex is totally flex-free with 4 layers.


----------



## demon2091tb

What exactly is the Kyntex?

Very nice tutorial btw, nicely done.

I used Extra strength Chopped matting, and 4-6 layers of it gave me a 1/8" of thickness, does the Kyntex stick to the surface or something special, never heard of it.


----------



## Relax

Where can you get Kyntex also?


----------



## dawgdan

It's all in the tutorial, near the top of the page.  There's all kind of commentary about Knytex, why Bondo brand resin sucks, etc.

"What is Knytex, and why use it? Knytex biaxial fabric is made by Owens-Corning. It is made up of essentially two layers of fabric – one side is stranded, and the other side is woven, and both materials are stitched together. Its primary use is for structural reinforcement in boat hulls. In this project, I used it as an alternative to regular chopped strand mat that's often used in fiberglassing projects (including this one). Chopped strand mat is great for certain purposes - tight turns, tweeter pods, and smaller fiberglass projects. But for making a subwoofer box, a thicker material, like Knytex, is preferable. Why? First off, Knytex is incredibly strong. When soaked with resin, using Knytex as reinforcement results in a much faster build-up. For impatient souls like me, this is huge. Three or four layers of Knytex will be as strong or stronger than 7-10 layers of regular chopped strand mat. In addition, for as thick as it is, Knytex bends around corners fairly easily. This stuff is excellent for building up a thick layer very fast."

You can buy it from uscomposites.com under "Specialty Fabrics". I bought 3 yards of the 17 ounce fabric.

It doesn't really do anything special except make for a much faster buildup. It lays up with resin very easily on flat and curved surfaces as long as they don't venture into being upside down (it's got too much mass to stick to a surface upside down). Once you try it, you'll see how much easier it is.  Seriously, a night and day difference.


----------



## WLDock

*"For over 10 years, I've been into car audio. I've always built big, rectangular subwoofer boxes that take up most, if not all, available trunk space in the vehicles I've owned. After getting married, settling down, and buying a house, it turns out that I need my trunk quite a bit more often than before."*

Oh my...you pulled my card with that. I have a 2 and 5 yr old and early this year picked up a nice used 300M and still find myself looking for space. That car has a very nice sized trunk but a box would ruin the layout. A side fiberglass box is the only way to really make use of the side space.

Thanks for the effort!


----------



## tyroneshoes

Nice job and great write up. Especially because I think we have the same exact car (6?)


----------



## dawgdan

You got it.


----------



## FoxPro5

How did you secure the box to the car??


----------



## dawgdan

Heavy-duty velcro. It already was a pretty snug-fit, and it doesn't really budge at all. That area of the car doesn't have a really good spot to sink a screw into, but I may do that anyways.


----------



## solacedagony

Where did you get your heavy duty velcro from?


----------



## bobditts

they sell industrial velcro at home depot and lowes


----------



## dawgdan

Yep, what he said. Lowe's.


----------



## tyroneshoes

Get the metra kit and a 880prs. Go active man. You got all you need but those passives are holdin you back.


----------



## dawgdan

Yeah, I know. The 3sixty.2 is on the wish list. For around the same price as the Metra + 880PRS (or any other really nice and flexible HU) I can keep the stock HU. I also need to add a second amp (probably a RF T5002) so that I can use the T4004 to power the each front driver individually.


----------



## illnastyimpreza

how did u estimate your box volume before hand?


----------



## DaveRulz

tyroneshoes said:


> Go active man. You got all you need but those passives are holdin you back.


Agreed, go active! Ijust swapped in CDA-9833 and pulled out my CDT passives. It made a world of difference. There is so much more detail now. Active is clearly the only way to go.

I just need more deadening in the doors, they are rattling like crazy now.

Fellow 6 owner/enthusiast


----------



## dawgdan

illnastyimpreza said:


> how did u estimate your box volume before hand?


As in, before I started building it? Honestly, there's not really a method to do it - I just sorta knew from past experience that 1.0 cubes, especially with a molded box, is quite often bigger than your mind may think. Basically, I got really lucky with the box volume.


Dave- Yeah, I'm the one who chewed you out on mazda6club.com for recommending Elemental Designs.  I will eventually go active when the funds allow. Christmas is coming soon, and my wife is about to receive a long list of items.


----------



## illnastyimpreza

whats wrong with elemental designs???


----------



## DaveRulz

dawgdan said:


> Dave- Yeah, I'm the one who chewed you out on mazda6club.com for recommending Elemental Designs.  I will eventually go active when the funds allow. Christmas is coming soon, and my wife is about to receive a long list of items.


I know, I know. Like I said, I've never had a problem with their products and I'm not using them in my car. Sounded like you had some bad experiences with Ben, and I guess it's just one of those situations where everything is just fine until there is a problem with the product and then the true colors come through.

I've had my CDTs running passive for over a year, and had never been super happy with the sound. I started with the tweeters in the stock locations, and they were painful to listen to, even padded down on the x-over. It seemed that no amount of EQ could fix the harshness at high volumes. So I moved them down to in front of the mids. I drilled out the holes in the door panel "grill" and mounted them behind there, aimed up at the listening position. This sounded better, but then it sounded like a lot of the highs were missing. So I reinstalled the stock tweeters in the sail panels, and ran them off of the image tweeter outputs on the crossovers. This was the best sound I could get out of the passive crossovers. When I pulled the passives, and just bi-amped the tweets and mids that were near eachother, crossed at 5k, the whole thing came alive. I remembered why I had gone active in my last full set up years ago.

Whatever, I digress... 

I do have a question for you in regards to the sub enclosure. I built a pair of enclosures for a friend's 6 very similar to the one you built (pix below). We used Home Depot resin and mat (because we were dumb and impatient) But I swear, we used 4-5 gallons of that stuff to get them done. Did it really only take a gallon of resin for you to create that entire enclosure? Would you attribute that to the kyntex?


----------



## dawgdan

Wow, Knytex or not, those are killer looking boxes!

When I did have to use chopped mat, I did notice that I needed to use more resin. So that's probably the case. Since the cloth is what gives resin its strength, I suppose that the dense Knytex fabric simply doesn't need as much resin. I was told by an experienced friend (the one that recommended Knytex) that it seems that most installs on the internet used way too much resin.

But yes, only one gallon to build the structure, with enough leftover to make the Bondo-Glass milkshake.


----------



## DaveRulz

ok, so kyntex it is for the next one! and thanks for the compliments. We were really happy with how it came out. Sounds pretty good too. Not the equipment I would have chosen, but it gets the job done.


----------



## dawgdan

Trust me, you won't regret going with Knytex. The layup method is a little different than the little strips of chopped mat. You can work with much larger pieces, and pre-fitting them really helps a lot. It lays around curves beautifully for as thick as it is.


----------



## Dichotomous

why did you mold off the interior fabric instead of cutting that away and going back to the metal frame? I would imagine you could get much more box volume without going into the trunk as much. is there some reason why doing so would be bad? if not I intend to remove as much carpet and foam and plastic that will just be covered up anyways as I can, to tuck it deep in there. also did you take into consideration the direction that the sub fires or is that not really all that much of a concern for your install?


----------



## illnastyimpreza

Dichotomous said:


> why did you mold off the interior fabric instead of cutting that away and going back to the metal frame? I would imagine you could get much more box volume without going into the trunk as much...


This is a good point... It would definatly help out the design of the box. But at the same time sort of kill any resale value you might be trying to save...


----------



## dawgdan

Because it's how I've seen it done before.  

Actually, my trunk trim is pretty thin. I doubt you'd gain much room behind there, if any at all.


----------



## DaveRulz

I've taken the side trim out, you wouldn't have gained much if any volume. In older vehicles you might. But in new cars they usually realize that space is a premium and make pretty good use of it. The best part of leaving it in is that it gives you a smooth, complete surface to lay your glass on. You also have to remember that since you're popping a mold, you have to be able to pull it straight out. All of the room that you would gain would make it impossible to pull the mold back out of the car. 

Also, as far as placement goes. In the Mazda 6, that's is the best placement. I've moved my sub into about every position possible, and that one sounds the best.


----------



## dawgdan

Agreed, Dave.

Also, maybe because it's in the farthest-corner of the trunk, I am noticing a little bit of a delay on the sub. The lower midbass (80-140 Hz) "snap" of a kick drum seems to hit just a tiny bit sooner than the seat-kicking thump. Need to get some time-delay soon to remedy that.


----------



## Dichotomous

never thought of the resale value afterwards, very very good point. 
as far as the time delay on the sub, if your sub is firing sideways instead of forward or backwards, there will be a bit of a time delay on it, not much, but a tad bit more than if it were forward/backwards. or it could be in the wrong phase and just SEEM to be delayed.


----------



## cthip

dawgdan said:


> Trust me, you won't regret going with Knytex. The layup method is a little different than the little strips of chopped mat. You can work with much larger pieces, and pre-fitting them really helps a lot. It lays around curves beautifully for as thick as it is.


a note on the knytex: i've read this tutorial before, and always assumed that knytex would be very expensive, but this is apparently not the case!

as i understand it, 17 oz knytex is two layers of woven cloth (approximately 8.5 oz each) with a layer of 3/4 oz chop mat between them. if you were to add up the cost of the three layers individually, you would be paying nearly double what the knytex costs. considering that the knytex may save you some resin money as well if you can use fewer layers, then it sounds like it really works out to be a pretty good deal to me.


----------



## dawgdan

cthip said:


> a note on the knytex: i've read this tutorial before, and always assumed that knytex would be very expensive, but this is apparently not the case!
> 
> as i understand it, 17 oz knytex is two layers of woven cloth (approximately 8.5 oz each) with a layer of 3/4 oz chop mat between them. if you were to add up the cost of the three layers individually, you would be paying nearly double what the knytex costs. considering that the knytex may save you some resin money as well if you can use fewer layers, then it sounds like it really works out to be a pretty good deal to me.


Good call.  On the surface, it may sound more expensive, but I suppose it does work out cheaper. Fewer buildup layers = time saved. In addition, people often forget (or are totally unaware) that resin is structurally brittle. The goal is to use just enough resin to saturate the fabric, and too often I've seen people really goop the resin on by the cupful. The fabric, not the resin, gives the enclosure strength. I only used one gallon of US Composites resin for my entire build, and still have a little bit leftover.


----------



## A6Bman

Thanks for this write-up! This was that one 'snap' article that makes me want to delve into building a fiberglass enclosure in my A6. Much appreciated!


----------



## dawgdan

Thanks for the kind words. Good luck with your project.


----------



## Coyote

Wow, this tutorial makes me feel like I can tackle this project on my own as well, thanks!

One question, how did you handle the sub wiring? I couldn't find that part.


----------



## dawgdan

I drilled a hole in the back of the box, in an inconspicuous area, ran wire through it, and sealed it up with some silicone. 

Not the most professional way to do it, but I didn't want to mess with terminal cups (I don't think there was a flat enough surface for a cup) and you couldn't tell once it was installed anyway.


----------



## ZoNtO

That's one advantage of running this enclosure. You bolt it to your frame, never take it out, so you don't need a terminal cup. For those tackling the project, make sure you give yourself enough wire slack to pull the subwoofer out of the box once you silicone it through the hole you drill. 

Makes me wonder if the one I ran is going to be long enough.....


----------



## A6Bman

Oh noes! That site is down! Does anyone have a pdf of this fiberglass tutorial?? I hadn't made one yet


----------



## Ge0

Excellent writeup Dawgdan. I read this every once in a while for inspiration. I'm going to glass some kick panels this up coming weekend and wanted to brush up on techniques.

Ge0


----------



## BlackSapphire

Ge0 said:


> Excellent writeup Dawgdan. I read this every once in a while for inspiration. I'm going to glass some kick panels this up coming weekend and wanted to brush up on techniques.
> 
> Ge0


FG kicks are in my near future as well. I wonder if Kyntex is even worth it for such small pieces. I've got tons of chopped mat.


----------



## dawgdan

Ge0 said:


> Excellent writeup Dawgdan. I read this every once in a while for inspiration. I'm going to glass some kick panels this up coming weekend and wanted to brush up on techniques.
> 
> Ge0


Thanks mang! I may undertake a new project shortly in my truck, before the kid gets here.  Gotta wait for it to cool down though.. glassing in 96 degree heat SUCKS!




BlackSapphire said:


> FG kicks are in my near future as well. I wonder if Kyntex is even worth it for such small pieces. I've got tons of chopped mat.


In that case I'd probably use the chopped mat. You already have it on hand, and kicks aren't terribly large, so buildup time wouldn't be too bad.


----------



## BlackSapphire

dawgdan said:


> In that case I'd probably use the chopped mat. You already have it on hand, and kicks aren't terribly large, so buildup time wouldn't be too bad.


By the way Dan (if that is your real name), I forgot to mention that your time and attention to the tutorial was obvious and appreciated.

Thanks.


----------



## sandman661

I am completely new to car audio minus the deck replacement here or there but this is my first jump into the mobile audio SQ pool, but not new to the interweb, and I have to say that is by far one of the most detailed, easy to follow tutorials on something I figured would be a hell spawned sucubus to try and tackle... I was thinking about having a shop build my box for me (I know I am on a DIY forum) because I had a table saw accident and left me partially thumbless on my good hand (of course it had to be my good hand)...But due to your time and great pictures, I think I am gonna try this myself...you might have saved me hundreds of dollars but just cost me hundreds of man hours...Damn you and thanks...LOL...


----------



## my89_928gt

Great job. Gives me idears.


----------



## WolfSong

Excellent write up!!! I'm another newb to the whole car audio thing, but I've been reading up and learning. Didn't want to kill my trunk space either with a big box, so after seeing someone else's DIY I decided to look into doing a fiberglass enclosure. I looked at several DIY's and other tidbits on fiberglassing, and then I happened upon your DIY.

It totally took the guesswork out of what I'd seen before. I've been modifying cars and guitars for years, and I honestly wish that more people spent the time you did to make an excellent step-by-step, well-documented and commented DIY.

Excellent work!!! I've got two cars I need to make enclosures for, and I'm really looking forward to getting started.


----------



## Auzivision

*Sub Box made using tutorial*

Thanks to your tutorial I tried my hand at this and was pleased with the end result. I’m sure you will recognize many of the ingredients. Following are a few pictures of all the fun:


----------



## Auzivision

More details... double click on thumbs to view full size:


----------



## MaXaZoR

Great writeup for beginners. One thing that should be added for a step which would make the both integrate more with the trunk is before you wrap it in carpet.
1.) Place the box in the trunk and align with how it will sit
2.) tape off all the edges where the carpet meets the box
3.) Take some Evercoat Everglass and with a glove/putty knife stare spreading it so it creates a seal to the carpet.
4.) let dry
5.) After sand down the edges so the integrate with the rest of the box and patch up any holes
6.) Carpet the box, and now you won't even notice the seam between the box and the carpet.


----------



## lowellbarrett

Dave, with regards to going active with your CDTs...

I have CDT ES-620s and the 560x-over, but I can go active with my amp's active x-over and have 75 to each driver up front. I have been discouraged by a few folks, including the folks over at CDT when I emailed them, saying that I need to be some kind of expert with serious RTF and other equipment to dial in the active setup. 

How did you do it Dave? Can you figure it out with a good ear?

Thanks for the info.


----------



## DaveRulz

Wow, old thread revival!

Going active with your CDT's (or any other set of speakers) does not require any experts or RTA tuning. It does require the ability to listen and make judgments on the sound. When I was tuning my CDT's (seems like eons ago at this point) I started with the crossover point that the passives were set at (happened to be 5k I'm pretty sure) I moved it up and down for the tweeter, and then up and down for the woofer until I hit the point where I thought it sounded best I think I may have had them a little bit underlapped to tame the harshness down low on the tweets. Then I used a little bit of parametric EQ to smooth the sound out to my ear and called it a day. Overall results sounded LIGHT YEARS better than the passives. For the reccord, most speaker manufacturers that tout their special, incredible, magic, spectacular passive crossovers are probably going to deter you from ditching them  Also, there is a metric buttload of information on this site about setting up and tuning active systems.


----------



## IMADreamer

I know this is an old thread but I wanted to say thanks. This is very helpful.


----------



## jgolomb

What a great tutorial for the fiberglass beginners out there! From years of searching for legit info on fiberglassing I have to say this is one of the best write-ups out there. That being said, I'd like to add a few things to attempt to spread some more knowledge on the subject.
I did years of fiberglassing while working in 12v, mostly more extreme fabrications and I thought I was pretty good at it, then I spent 2yrs working for a new OEM boat manufactuer and learned that most of what I thought I knew about fiberglass was wrong, well not entirely wrong but misguided would be a better way to put it. I'm only adding to this thread because I'd like to see the mystery and myth dispursed all over the 'net come to a halt and this tutorial is a fantastic start compared to everything else I've run across. Ok, on to the good stuff:
1. A few more things to add to the supply list:
A metal roller - *critical* for a good lay-up of ANY type of fiberglass mat
These rollers can be ordered from US Composites, smaller ones are much easier to work with, it will have a plastic handle and the actual roller is about 1/2" thick, about 3" in length. The roller itself is metal and ribbed with deep grooves in it, handle is shaped like a mini house paint roller.

2. A scale for mixing the MEKP with the resin. Catalyst is added to resin according to the weight of the resin, not the volume. In this tutorial US Composites provided the proper ratios to mix this particular resin, I'd still use a scale to be sure. When ordering the resin, ask for a catalyst measuring chart. This is also very important, particularly for longevity of your project. Why? As mentioned, resin is very brittle in it's own nature by itself, too much hardener (MEKP) and you'll have problems either now or a year from now. A hot (too much MEKP) mix will actually give a _weaker_ end result, tend to warp while drying (creates hot-spots on the project which shrink and pull because of the heat generated), be prone to cracking months down the road (which really sucks if you've painted your project, looks great and it cracks from the inside out a year later - been there), shorten your work time for the lay-up, make it more difficult to get to fiberglass fully wetted out.
A chart will give you different percentage mix ratios, generally 2% is what you will use for most conditions - if it's summertime and real hot it's not a bad idea to drop to 1 1/2%. Ambient temperature plays a pretty good role in the initial curing time of the resin. This may all sound confusing but when you look at the chart it becomes plain as day to understand how much MEKP to how much resin. Example; 2lbs of resin mixed at 2% uses 7-8cc of MEKP, 1 1/2% would be 6-7cc of MEKP.
Use the scale (any scale will work that reads pounds and ounces, even a postage scale) to determine how much resin you've poured out to work with, then refer to your chart to add the MEKP. DON'T add a little extra for good measure, more is not better - avoid temptation! Mix the MEKP with the resin really well with a paint stick, again - mix it well.

Now that we've got those details out of the way, what do we use the roller for? When you are brushing the resin onto the mat, don't over do it with the brush. Use the brush to get the resin onto the mat, then it's roller magic time. Start rolling the resin out on the mat to wet it out and get it into the cloth. Just roll quickly back and forth all over it, the roller will actually spread the resin around a bit and get it distributed nice and evenly. It will push the mat down to your work surface and also removes any air bubbles which is *vital* for strength between your layers of mat. The roller is your best friend while laying mat! Using a roller will significantly reduce the amount of resin you use, roll just enough to where you can see through the mat and there is no white color visible. If you have air pockets or puckers, roll over them in different directions and they will go away. You can roll as fast as you want, add resin with your brush as necessary.
Side note - if it wasn't mentioned you should (read must) have rubber gloves on at this point - really anytime you're breaking out the resin from the point of pouring and mixing on. _Handy trick_ - put on two pairs of gloves, one over the other, when you're in the middle of your layup and you've got sticky hands from the resin and the mat fibers are sticking to your hands (especially if your using chopped mat) - you just pull off the outer layer of glove, toss em' and keep on working.
Why is the roller so important? Resin distribution and more notably eliminating air bubbles, even the little tiny ones. Think about it, if there is an air bubble between one layer of mat and another you no longer have a layer at that spot - which means it's a weak spot and kind of defeats the point of layering the mat to begin with. A roller will eliminate trapped air between the layers and is good for getting the mat conformed the way you want it. After seeing and knowing the difference I'd never consider laying fiberglass without one. Plus it makes a huge difference in resin useage! Rule to resin, use only what you need to wet out the mat - any more is simply wasting resin and adding weight. Most people, including myself for years, use too much.

3. Acetone
Used for clean-up, it's pretty much the only thing that will get resin off something, inculding you and your skin. Word to the wise - acetone is really nasty stuff, especially on your skin. You don't want to spill it!
Use one of your mixing containers to pour some acetone in, while doing your lay-up with the mat keep your roller in the acetone bucket when not using it (you don't need a lot in there, pour about 2" in the bucket) This will keep your roller nice and clean while working, don't worry about it having acetone on it and getting it on the resin, just shake it once or twice when you pull it out of the bucket - you're not going to contaminate the work with that little bit that's left on there. When you're done, drop the roller in the bucket and just let it soak while cleaning everything else up.

A few other notes:
Types of mat - the material used is indeed a bi-axial, you don't have to use that particular brand but he's dead on about the strength difference. There is also tri-axial available as well, great for mostly flat areas, hard to contour much around curves or bends. US Composites has a great selection, call them with questions.
In between layers, use a piece of 80-grit and scuff the surface of the resin between layers. Most resin manufactuers add a waxy surfacing agent into the resin that rises to the surface as it cures. You want to scuff this off the top between layers of mat, it hinders the chemical bond between layers of mat/resin. Just scratch it up good and that's it.
Chopped mat - it is noted to tear the edges, not cut with scissors. You want a frayed edge on all sides, this makes a huge difference in getting it to lay down right and not keep lifting up on the edges while trying to wet it out.
Sharpie marker - notice in the pics how the sharpie marker he used to mark the cuts in the biax mat were visible after it was wet out? A sharpie marker will bleed into resin, when taping your area off that's a great time to draw the shape on the tape where you plan on cutting for the edge/outline of your project. The line you draw on the tape will transfer to the glass' giving you a good cut-line to go by when trimming. Helps to eliminate a lot of guess work when you pull the backside mold out of the vehicle and go to trim it. 
Stretching material - you can use just about anything that's nice and stretchy, thinner material is often better. Fleece works but I only use that for really big projects, down side to fleece is that it soaks up a ton of resin and isn't really that strong compared to how much resin it soaks in and can create a pretty rough surface depending on what kind of fleece it is. The material gives you your shape, not strength - that's what the fiberglass is for. Stretchy velour works really well for a lot of smaller projects like kick panels, look for materials that stretch well and have a 'medium' bulk to them for bigger stuff. If you are using fleece, try to find some that has a fairly smooth side to it - which you will face outward. When pulling the fabric, CA glue works really well for holding it in place without staples but you have to use a good bit of it - worth doing though, cause' then you come back after it's glued down and trim with a razor right where you glued it for a no-fuss backside to the project. You squeeze the CA onto the fabric right where you would staple it, it soaks in very quickly, spray some accelerator and bingo...

I think I've covered the important stuff, at least what I've learned from being in the marine world for a bit - hope this will help, I sure wish I had known all this a long time ago! Again I'd like to give major kudos for the write-up, an awesome cover of the basics and really impressive first project! Way better than my first go-around from what I remember!

- Jeff


----------



## The Buzz

Nice Job! I LOVE the Bondo milkshakes. Been using that formula for years and it has some awesome applications.


----------



## cerberus25

The nylon rope to create a rigid supportive skeleton is absolutely brilliant! That's going to help me a lot in my future endeavors. Thanks!


----------



## kyledtyler

I can not freakin wait to get started on my own project. I have been wanting to do a fiberglass enclosure for a while. Thank god I stumbled onto this website and this forum. Keep up all the good work and thanks for all the advice for all us newbies!


----------



## brianalexander

thank you so much for this tutorial. It totally helped me with creating fiberglass door panels for my golf!


----------



## predatorftp

Great work looks owsome !


----------



## bsully1850

Thank you!


----------



## cobraa

Nice tuto, I think I will follow this one to make my box!


----------



## bsully1850

Great tutorial!


----------



## leorbolato

Fiberglass itches a lot...


----------



## bawward

Dan, I emailed you and just want to thank you so much for the AWESOME write-up! This was huge, and now I'm going to get on to designing my box! Thanks a ton, and way to make it easy! 
Also, thanks a bunch to jgolomb for the extra tips, they will be very helpful... I just hope that roller isn't $20! jk 

Thanks again guys!


----------



## ChiTownSQ

Got a question: 

How well does the first parts of the mold work when you have to glass up into an area that is free fall. Like a roof corner or something that is not right side up or even 90* any hints and tips for that?

Also.. and this i have been trying to figure out. When you stretch mold fabric for a pillar install. how do you secure it on plastic? Do you glue it, or staple it. and how do you staple it and then still remove the staples in the resin?


----------



## eviling

very nice, not knowen it was mentioned but aluminum foil can be used, to ensure a clean pull away. i've seen it, idk the lagistics but i believe foil will be my method over the PAM, but it's all the same result i suppose.


----------



## TimesCaptured

Wow thank you soooo much. 4 years old and still dead nuts on.


----------



## LiquidClen

FoxPro5 said:


> How did you secure the box to the car??





dawgdan said:


> Heavy-duty velcro. It already was a pretty snug-fit, and it doesn't really budge at all. That area of the car doesn't have a really good spot to sink a screw into, but I may do that anyways.


Are you ever worried about it coming loose? If you were to screw it in, would you just drive the screw straight through w/ a washer or L Bracket?


----------



## ChiTownSQ

I wanted to quickly sing the praise of the Bondo Milkshake... First time used it last night.. it is awesome.. you can paint it on and it works fantastic for leveling mistakes in the mold fabric, back filling voids and generally easier to use than filler at finishing off surface areas.


----------



## travanx

Thanks for the article. This will be the 4th box I build, but the 1st not using Home Depot/Lowes materials. Can't wait for the US Composite stuff to arrive. Will be making a box in my Honda S2000 for an 8" sub, will easily be smallest/most compact build I do for a car. =)


----------



## ScuLt

Good tutorial. i'm planning to construct a box below the front seats in my car.

Does anyone have an idea to do this one? I was thinking to use fibberglass in the bottom and board in the top and sides.

How could i fix the board on fibber?


----------



## chtaylor71

Great Write up...Thanks for the info


----------



## vanable

It's always cool to see other people's projects presented in a how-to manner like this. I was glad to see you took the extra step in fabricating ribs into your structure. That's something a lot of folks seem to overlook, and it goes A LONG way towards increasing the rigidity of the enclosure (without having to go crazy with adding tons of layers). Something that's worked well for me in the past is to use strips of foam weatherstrip that you can get at most hardware stores. They have a peel-off adhesive back, so they're easy to attach, and come in long rolls... so you can just cut strips to length, peel the backing, and stick them to your structure. Once you lay on the 'glass, it'll form a strengthening rib over the strips, and you're good to go..!


----------



## Jprice2708

Thanks very much! This tutorial is great! Exactly what I need to show me how to do my sub install. now to buy the gear and get to work...


----------



## edouble101

Thank you for taking the time to write this up.


----------



## BigEasy

Great write up! I'll definitely use this in the future


----------



## travanx

Wow just used this cloth and resin. I have made 4 other boxes using the stuff from Lowes and Home Depot. I can't believe how much easier this is to work with, even around corners. And its less layers to get such a better structure. I am waiting on a ring through the mail before I finish off the 2nd half. First half took me half of the day today.


----------



## h1-vltg

Excellent write up, I wish I read this before I bought the "junk" stuff.


----------



## PttColt

eviling said:


> very nice, not knowen it was mentioned but aluminum foil can be used, to ensure a clean pull away. i've seen it, idk the lagistics but i believe foil will be my method over the PAM, but it's all the same result i suppose.


I sometimes use foil when creating my molds. I still use tape, but just around the edges and in spots where I think a leak can occur.
When using foil, I found its best to use a mold release. I've had the foil stick to my mold.. and it was somewhat difficult to remove. I've also tried WD-40 (instead of pam or wax) in the past and it was pretty useful.


----------



## mine4118

great post and the product list is perfect...thanks


----------



## fatboy.yoshi

awesome, i hope to try this out one day


----------



## Vitty

Great tutorial. Always wanted to do a glass box. Now I may actually give it a go


----------



## Beats_by_Boat

Thanks to the OP. 

Been thinking about an enclosure to build into my spare tire well with a false trunk floor. Definitely want to do this box build method. Probably a single DynAudio MW190. Should be interesting.


----------



## quietfly

i know its an old thread but its still a great write up!!! thanks!!!


----------



## eXcelon969

newbie question:

doesn't the staples to hold the fleece on poke holes in the fiberglass or are you guys using 1/8" staples?

i just ordered from us composites and they do not have b-440 anymore so i got 435


----------



## Palos

bump!


----------



## Andys2000

six years later, this tutorial still rocks.


----------



## ek9cv5

Just what i needed thank you so much


----------



## MUGWUMP

I've something to add about resins.

The first I used was the US Composites. It's was really easy to work with and I had about 15-20 minutes of work time. It would take 24 hours or so to cure.

I ran out of that and tried the 3M stuff. It was like molasses. Very difficult to work with and I had about 3 to 4 minutes of work time before it kicked. I didn't bother to try it again.

I went and got West Marine boatyard resin and the stuff is pretty impressive. I still only get about 5 minutes of work time, but it cures fully solid in 4 hours. It contains wax so sanding is necessary if you wait longer than 30 minutes between applications. I have to work in small 4oz batches, but I really like how fast it cures. Great for small projects.

http://www.westmarine.com/webapp/wc...toreNum=50218&subdeptNum=50219&classNum=50221


----------



## [email protected]

Great write up! I often send this link to those with questions on my work.


----------



## Tunalollipop

I am going to give this a go! I like learning how to do things myself and this is something I was actually considering seeking out someone local to do.


----------



## Ripsnort

Excellent post! Thanks for taking the time and effort to get this out there. Very useful information ~


----------



## aznbo187

MUGWUMP said:


> I've something to add about resins.
> 
> The first I used was the US Composites. It's was really easy to work with and I had about 15-20 minutes of work time. It would take 24 hours or so to cure.
> 
> I ran out of that and tried the 3M stuff. It was like molasses. Very difficult to work with and I had about 3 to 4 minutes of work time before it kicked. I didn't bother to try it again.
> 
> I went and got West Marine boatyard resin and the stuff is pretty impressive. I still only get about 5 minutes of work time, but it cures fully solid in 4 hours. It contains wax so sanding is necessary if you wait longer than 30 minutes between applications. I have to work in small 4oz batches, but I really like how fast it cures. Great for small projects.
> 
> WEST MARINE 004_120_002_501 at West Marine


Did you need any hardener or a second part to the resin? Or simply apply fiberglass mat + resin...and let it dry and that's it?


----------



## SuMb0dY

The tutorial was great thanks for the tips. I started making my own fiberglass box this week. Made the mold shape in the car Tuesday night. Let it cure, and pulled it out last night =D It's a very fun process and I can't wait to finish it and hear my creation in action.

In the tutorial you hosed it off and found a leak - Isn't it a bad idea to get those MDF mounts wet? I would think that would soften them up and make them too weak for a sub. I can see trying to vacuum out any loose pieces inside the box to clean it up but I would try to keep water away from the ring if I could. 

I was thinking that I should coat the inside of mine with bondo to ensure it's air seal as well. How much effort should I put into make the seal really air-tight? Should I go nuts trying to make the box air tight around the speaker terminals and using rubber gaskets around the speaker?

Is it feasible to make it the 'perfect enclosure' or do 'sealed' boxes rely a bit on a tiny air leak to control the woofer cones movement?

I was planning to try and make this completely air tight but then read a thread on here about how no one really has the perfect enclosure so I got confused. My old (10+ year old) subwoofer's foam surround tore all the way around. Sure it lived its life awhile but I thought maybe because it had air leaks (it had no rubber gasket around the speaker mount/box) that promoted the cone surround to break so I thought to treat my new woofer better I should really go crazy with the air sealing process.

Sorry for the long winded post, any thoughts on this guys?


----------



## theoldguy

a lot of work to build a box when you could jsut use MDF  (a box is an object with 6 flat sides.


----------



## SuMb0dY

Haha yes very difficult to get all the corners and angles perfect 90 degrees


----------



## Project_dog

Thank u


----------



## x97chevy

That is an awesome write up!!!


----------



## shoot summ

Thanks for your effort putting the guide together, yours is actually one of the resources I used in making mine. It is still in progress but will have it finished this week. For those that state it is a lot more effort than building an MDF box you are right, but it is also way cooler, and more space efficient than a plain old MDF box.


----------



## eddie298

this is awesome, when i eventually buy a subwoofer, im definitly going to try this.


----------



## bobwires

I don't mean to be a giant turd in the punchbowl here, but this thread needs help. The basic process of the OP is just fine, but the glass work itself is very poor. There is way too much air in your layups. Proper wetout, consistent thickness, and proper resin:glass ratio are all easily reachable goals with just a little practice.

I don't want to come down to hard, because we've all been here, but the standard for a 'reference thread' should be much higher.



Here's a couple nice layups. If you want to see my ugly years getting started, check out the comatose fiberglassforums.

I have been using dye in my resin for the last couple of years. Looks cleaner.










Kick panels



















Use wax or silicone spray to make your tape release 100%. 










tape off the inside of your rings so you don't have to sand them. Also, leave yourself an edge to sand to by always rabetting the edge of the ring, if it's wood. 

Also notice I used foam on these instead of fleece. Get the shape you want before you fill it. Don't try to use a gallon of bondo to correct imperfections in the shape. If you want the fleece look, make ribs/strips of wood to hold it there.










Nice and clean - skim filler and sand before you pull the tape of the middle.











Always glass the outside of the enclosure to ensure a good layup, uniform thickness, etc. Way faster, easier, stronger, better. period.










Some of these things don't need filler, if they're carpeted.










I primered this box with no sanding at all just to show how flat it should be. I knocked it with a d/a real quick, and wrapped it in carpet.


----------



## quietfly

bobwires said:


> Also notice I used foam on these instead of fleece. Get the shape you want before you fill it. Don't try to use a gallon of bondo to correct imperfections in the shape. If you want the fleece look, make ribs/strips of wood to hold it there.


can you explain/show this in pics?


----------



## bobwires

pour foam kick panels

http://www.diymobileaudio.com/forum...allery/121177-kick-panels-bobwires-style.html

my old method using fleece and foam in combination. This takes a lot of time, and I don't think I'll be doing it again.

http://www.diymobileaudio.com/forum...gallery/121181-jl-tahoe-semi-stealth-box.html

floral foam used for trim

http://www.diymobileaudio.com/forum...baru-hertz-rockford-fiberglass-enclosure.html


----------



## quietfly

thanks for the links... I think i might try foaming up some stuff....


----------



## Earful

This thread is fantastic! Many chime-in's to assist those, like myself, who dont have any experience with glass. Custom enclosure nirvana....


----------



## KaotikKustumz

LOVE THE TUTORIAL!!!!!


----------



## SuperGokuSon

WoW im a total nood when it comes to this and now i feal like i could give it a shot and see what haponds i loved how you calculated the cubs of the box so simple. and i do not feel like such a dummy now lol


----------



## loudnproud808

been checking out these forums for years , and now finally made an account , nice thread this whole forum is awesome ! i have recently been thinking about trying this fiber glass enclosure builds myself !


----------



## ndramountanis

Fantastic Tutorial! Thanks for doing all that posting work.


----------



## liljohn30

Who in Atlanta can do this work


----------



## The Performer

bobwires said:


> I don't mean to be a giant turd in the punchbowl here, but this thread needs help. The basic process of the OP is just fine, but the glass work itself is very poor. There is way too much air in your layups. Proper wetout, consistent thickness, and proper resin:glass ratio are all easily reachable goals with just a little practice.
> 
> I don't want to come down to hard, because we've all been here, but the standard for a 'reference thread' should be much higher.
> 
> 
> 
> Here's a couple nice layups. If you want to see my ugly years getting started, check out the comatose fiberglassforums.
> 
> I have been using dye in my resin for the last couple of years. Looks cleaner.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Kick panels
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Use wax or silicone spray to make your tape release 100%.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> tape off the inside of your rings so you don't have to sand them. Also, leave yourself an edge to sand to by always rabetting the edge of the ring, if it's wood.
> 
> Also notice I used foam on these instead of fleece. Get the shape you want before you fill it. Don't try to use a gallon of bondo to correct imperfections in the shape. If you want the fleece look, make ribs/strips of wood to hold it there.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Nice and clean - skim filler and sand before you pull the tape of the middle.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Always glass the outside of the enclosure to ensure a good layup, uniform thickness, etc. Way faster, easier, stronger, better. period.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Some of these things don't need filler, if they're carpeted.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I primered this box with no sanding at all just to show how flat it should be. I knocked it with a d/a real quick, and wrapped it in carpet.


It is so good to see a glass veteran stepping in. 

Dude maybe you know wth is the deal with fgforums? All the good fab guys are far and few to keep up with anymore. 

Sent from my SCH-I545 using Tapatalk


----------



## liljohn30

What the hellz up with that forum,fiberglass forum..I joined but it never went through..I was gonna try this ,but kinda gave up,n an looking for someone to do some work in my dodge ram.i wanna do a center console with wood n glass,and then do a mold of the storage bins to try n put in some subs n retain the fold floors


----------



## Ordie

Its been down for a while... 

Sent from my mind to the forum through a Galaxy SIII and Tapatalk 2.


----------



## The Performer

liljohn30 said:


> What the hellz up with that forum,fiberglass forum..I joined but it never went through..I was gonna try this ,but kinda gave up,n an looking for someone to do some work in my dodge ram.i wanna do a center console with wood n glass,and then do a mold of the storage bins to try n put in some subs n retain the fold floors


http://pascackvalleyhome.com/wp-content/uploads/2011/07/WHAT1.jpg

Sent from my SCH-I545 using Tapatalk


----------



## mikelycka

this is a great post now I feel better about wanting to try this my car is leased and I don't want to damage anything but I also need to use my trunk


----------

