TeamSwift

Home of the Suzuki mini-compacts ! Your Home for all things Suzuki Swift, Geo Metro, Holden Barina, Chevy Sprint, Pontiac Firefly, and Suzuki Cultus. TeamSwift is a technical performance oriented community!
It is currently Mon Nov 20, 2017 4:44 pm

Underbody braces, turbos and more!

All times are UTC - 5 hours




Post new topic Reply to topic  [ 14 posts ] 
Author Message
PostPosted: Sun Oct 26, 2003 5:18 pm 
Offline
King of Pompous
User avatar

Joined: Sat Aug 25, 2001 4:22 pm
Posts: 5596
Location: Ottawa ONT.
OK guys, Here's a quick primer on building a fiberglass sub enclosure. Fiberglass offers a few benefits to typical wood. 1. Fiberglass is much lighter than MDF or even low void plywood. 2. Fiberglass is extremely strong. This makes it possible to make the enclosure thinner than a wooden enclosure further cutting the weight down. 3. Fiberglass can be made into any shape. You are limited only by imagination. Also, because of it's ability to conform to anything you can take advantage of every square inch of space that you have.
The enclosure you are looking at was built to take up the back seat of my Swift and is just over 6 cubic feet internal volume ported to 25Hz. The beginning part of the buildup is identical to what you would do for a spare tire well enclosure and there have been a few people wondering about this. If you guys have any other q's just let me know and I'll answer them to the best of my knowledge. Here goes...

SUPPLIES NEEDED:

Polyester resin
MEKP catalyst
Chop mat
Dust mask or respirator
Bucket for mixing
Patience
Measuring cup for MEKP
Absolutely the cheapest brushes you can find
Heavy duty foil (cheapest)
Duct tape (cheapest)
Stir sticks
Bondo w hardener
Patience
Box to hold mat
Dowel
Glue gun
Saw to cut rings
Staple gun
Fleece
Sandpaper
Latex/vinyl gloves
Oh yeah...did I mention patience?



PIC 1:
Image

In this pic you can see what I did to protect the body from gettig messed up with resin.
There is a number of ways that you can do this (wax, vaseline, release agent, ect)
but I find this way much faster and less messy. Basicaly
I've covered the entire area that I will be working in with a couple of
layers of heavy duty foil and then covered all that with a layer of duct
tape. You will want this area to extend beyond your work area to make sure
that you dont get resin on it. IF YOU GET RESIN SOMEWHERE AND IT CURES IT
WILL NOT COME OFF!!! Make sure you protect the car.

PIC 2:
Image

Make your frame. I use 3/4" MDF but low void plywood weighs less. If this
was a spare tire enclosure you would have a basic square that would come up
flush with the top of the enclosure. Double check and then double check
again on your measurements. Once you have the glass on this if you were off
you will have to start right over. You also want to make sure that the
fiberglass (or resin) will not be able to run into little nooks that will
get your enclosure stuck in your car. Seen it happen before when the tire
well's base was a little larger than than the opening. This guy did 7 layers
before he tried to pop it out. LOT's of cursing and frustration.

PIC 3:
Image

This picture shows the first few layers of glass going down in the car. On
my first layer I used glass weave. I used a big chunk and stapled it to the
MDF so that it wouldn't go anywhere. Resin is very sticky and can "grab" the
mat and try to lift it. After the first layer was soaked I started using
chop mat to cover and soak up the remaining resin. It doesn't matter how many layers you do at once
but I would suggest doing one at a time if you've never used glass before.
Resin mixtures vary according to temperature and humidity and until you get
used to that it will waste a lot less resin if you mix a big batch and it
cures before your done layering. I do a gallon at a time for this part
because the resin pools a bit but let's me drop a LOT more mat down to soake
it up. Going with thicker layers also lets you mix the resin a little bit
cooler because there will be more of it trying to cure at once.

PIC 4:
Image

This pic skips over a bit. As you can see the bottom portion of my enclosure
is finished. I went to about a 1/4" before I popped it out of the car.
Because I used the foil/tape barrier it simply lifted out. If this was a
spare tire enclosure you would now just have to attach your top board to the
frame and mount your sub. I'm going a little further with this one though.
I've cut rings for my subwoofers and used dowel to hold them where I want
the subs to be. Make sure that the rings are very solid. The fleece will
pull really hard on them. I used high temp hot glue to hold them in. That
square board is where my port for SPL will be. When you do the ring thing
double check IN THE CAR if you will have clearance! Add about a 1/4"-1/2"
around the rings for clearance because there will be fiberglass there.

PIC 5:
Image

This pic shows the fleece stretched over the rings now. It also shows the
first layer of resin. I did two coats of resin on this one. The resin I used
was very thin otherwise one coat is usualy sufficient. You can tell when the
resin cures if there are soft spots. If there are soft spots you can mix a
small batch and recoat the spots. I stappled the fleece on to the enclosure
with about 3/4" spacing. Make sure that your fleece doesn't have any runs in
it when you stretch it around the rings.

PIC 6:
Image

This pic skips through about 8 layers of glass. I usualy try to get a
thickness of around a 1/4" but there is a large flat surface on the top of
this box so I went to about a 1/2" thick on the top. Fiberglass is stronger
in curves so keep this in mind when you buld your enclosure. This box was a
PITA to do. We were going through a heat wave and the temps were around 45C
with humidity. In this heat you have about 1.5-2min to work in unless you
mix the resin really cool. On the third or fourth layer I mixed a little too
hot and the resin cured REALLY quick. I didn't have time to push out the air
bubbles and you can see a few of them. This isn't a problem as you just have
to grind them out (you can see an area along the back of the box were this
was done) with a Dremel tool or the like. Air bubbles can be difficult to
work out in such a short space of time. I use a pick and a 3" brush with the
bristels cut down to about a 1/2". I stab the bubble with my left hand and
push the air out with the brush in my right hand. Oh yeah, on the first
couple of layers you may find it hard to get the mat to hold unless it's on
a horizontal surface. I usualy put resin down and then put the layer on top
of it pushing it on with the brush. It may take a few tries to get this
right but you will get the hang of it. You can use a spray adhesive to hold
the mat and them resin over it but I find it unecesary once your use to it.

PIC 7.
Image

Here is a pic of the first layer of Bondo. I use lighweight filler on stuff
like this Not much to say here but that your in for a lot of sanding. I find
with filler your better to start with thin layers and work your way up. If
you go with a thick layer you risk cracking the filler. Those black spots
are the fiberglass layer underneath. You can see from this that it doesn't
take a lot to make it look smooth. I had to do the sanding by hand and it
took a long time. I actualy havent got it finished yet. I threw a quick coat
of paint on it 'cause I was dying to hear it and if I had finnished it first
I wouldn't have had time to get it in this year. An air sander will save you
TONNES of time sanding a project like this.

PIC 8:
Image

This shows the unfinished box in the Swift. It's got a coat of black on it
so you can see the little flaws that will get sanded out this winter. After
that it will get painted in a spray booth and will look like a mirror. You
can also see that with this box I have all the cargo space I would have with
the back seat up and my spare tire still (I can still squeeze my mountain
bike there!). With the carpet on the box it looks just like the rear seat is
in through the tint. Sounds awesome and there is now a port in it that's
tuned to 25Hz. With only 700W going to it I'm guessing I'm in the low to mid
140's. This may not sound like much for a pair of 15's but it's with a very
low tune. Going to an SPL tune will have this sytem in the low 150's with
the amp at 1 Ohm pushing around 2000W.

I'll have another FAQ coming up in the next little while on building door pods too. Hope this was helpful for a few people.

Later

Andre

_________________
LNLC Founding Member

FAKE FRIENDS: Never ask for food.
REAL FRIENDS: Is the reason you have no food.


Top
 Profile  
 
 Post subject:
PostPosted: Wed Aug 11, 2004 11:57 am 
Offline

Joined: Wed Aug 11, 2004 11:51 am
Posts: 2
Location: MidWest
How long did you have to wait for each layer of fiberglass to cure?

_________________
Image


Top
 Profile  
 
 Post subject:
PostPosted: Wed Aug 11, 2004 1:04 pm 
Offline
King of Pompous
User avatar

Joined: Sat Aug 25, 2001 4:22 pm
Posts: 5596
Location: Ottawa ONT.
Depends on how you mix the resin. Usualy you have about 5-7mins of cure time. You have to be careful when you mix it though. On a hot day you need less hardener and on cool days you need more. Avoid working in direct sunlight on very hot days or the resin will cure very quickly and that makes it a PITA to work with. Also, when the resin cures too fast it becomes brittle. Follow the instructions on the container on resin and hardner...they usualy have a couple of ratios to follow. I'll see if I can find my mixing chart somewhere...look, I'm retarded won't happen for a little whiloe 'cause I have a lot of stuff packed for a move right now though.

_________________
LNLC Founding Member

FAKE FRIENDS: Never ask for food.
REAL FRIENDS: Is the reason you have no food.


Top
 Profile  
 
 Post subject:
PostPosted: Wed Aug 11, 2004 1:21 pm 
Offline

Joined: Wed Aug 11, 2004 11:51 am
Posts: 2
Location: MidWest
Alright, thanks alot! 8)

_________________
Image


Top
 Profile  
 
 Post subject: will a sheet work..
PostPosted: Mon Aug 23, 2004 8:43 pm 
Offline

Joined: Mon Aug 23, 2004 8:40 pm
Posts: 1
Location: Whitehorse
Hey i was wondering if you could tell me if a cotton bed sheet would work rather then fleece and do i have to make it like totally enclosed like can i make it have a port and do i gotta enclose each sub spot?? and instead of using mdf can i use just straight up ply wood??

Thanks


Top
 Profile  
 
 Post subject: Re: will a sheet work..
PostPosted: Mon Aug 23, 2004 10:07 pm 
Offline
King of Pompous
User avatar

Joined: Sat Aug 25, 2001 4:22 pm
Posts: 5596
Location: Ottawa ONT.
putland_22 wrote:
Hey i was wondering if you could tell me if a cotton bed sheet would work rather then fleece and do i have to make it like totally enclosed like can i make it have a port and do i gotta enclose each sub spot?? and instead of using mdf can i use just straight up ply wood??

Thanks


You can try to use a cotton bed sheet but some cotton sheets have elasticity made into the fabric. When you apply the resin it can cause it to lose it's shape during the curing phase. Fleece tends to soak up a bit more resin and gives you a harder surface to work with. I used Grill cloth on my enclosure and even though it was very stretchy it didn't cause me any problems.

Ports can be a little tricky do do with glass. Without knowing the exact volume of the enclosure (because it is an organic shape) you would have to guess a little with the lengths to get the proper tunning. If it were me I would make an area for were the port is going to be and add it after you've layer all the glass and measured the volume. You can then use a hole saw to cut the hole out for the port itself and get the tunning frequency right te first time. You don't have to enclose the sub holes but it is easier to make the fleece remain smooth. I usualy leave mine covered to the end to keep dust and crap out. I had to open the ones on this enclosure because we were in the middle of a heat wave and I needed a way to get some of the heat out of the enclosure 'cause it would have melted the hot glue holding the supports on the sub rings.

Plywood can be used as it's lighter than MDF and holds a screw better. Make sure you get low void plywood though as you don't want to do all this work and have a crummy piece of wood mess it all up.

_________________
LNLC Founding Member

FAKE FRIENDS: Never ask for food.
REAL FRIENDS: Is the reason you have no food.


Top
 Profile  
 
PostPosted: Wed Feb 09, 2005 6:56 pm 
Offline

Joined: Wed Feb 09, 2005 6:38 pm
Posts: 1
Location: Manchester, Kentucky
Alright man, Thanks for the detailed description on the process. Me and a friend of mine started our first fiberglass box and it is working out well, but the walkthrough that we got out of a magazine is alittle different than yours. I have some questions.

1.) The directions we have indicate to use only a couple of layers of fiberglass then reinforse the inside of your box with bondo and steel mesh. Which method is better, or does it depend on the design of the box your building?

2.) I noticed you used fleece. We did too. We did not know where to find fiberglass matting, but as far as we can tell it is the same thing just cheaper at WalMart. Is this true?

3.) Is there a mathematical formula to correctly port a box?

4.) Where the hardened fiberglass meets the wood there is always an uneveness. If you decided to paint the whole box does the bondo cover both the fiberglass and the wood too and then you just paint over and there is no difference or what? How does that work?
[/b] I would appreciate you emailing me the answers to these questions. I would be grateful! nickmays04@yahoo.com

_________________
Hey man, I just want to drive fast, and sound good! CARPE DIEM!!


Top
 Profile  
 
 Post subject:
PostPosted: Wed Feb 09, 2005 9:50 pm 
Offline
King of Pompous
User avatar

Joined: Sat Aug 25, 2001 4:22 pm
Posts: 5596
Location: Ottawa ONT.
I'll answer you here and then I'll also email it to you.

1. Unless the enclosure is for low power and it isn't very big your gonna want more than a couple of layers. Shoot for 1/4" thickness throughout. If the enclosure has large flat areas then you will need to go thicker...closer to 1/2 and inch. I haven't heard of the steel mesh reinforcemnet before. i have heard of using chicken wire to form a shape for an enclosure though...could that be what they meant? Bondo should not be used to reinforce anything because it is not strong at all. Bondo should be used only to make the enclosure smooth. All the strength comes from the fiberglass and bracing.

2. If you mean the fiberglass mat you get in the auto section at Wal mart then yes, it's basically all the same. Thicknesses (weight) will vary though and the walmart stuff is pretty thin. Just means that you will have to put a few more layers to acheive the same thickness that you would with another mat of heavier weight (thickness).

3. There is a mathematical formula. You can find it on the JL Audio website if you like math. I use WinISDPRO (freeware) to calculate my port lengths for a given enclosure.

4. You need to sand it down as smooth as possible. It's hard for me to answer because I can't see the actual piece. I try to make my transitions from fleece/mat as smooth as possible to the MDF. I usualy staple the fleece down and cut the excess fleece off as close as possible to the staples to make it more smooth. When the fiberglass goes on you need to make sure that there are no air bubbles near the edge or it will picj up as it cures. After your all done then it get's sanded down and Bondo is put on top. Sand that down smooth and your good to paint. It may take a few Bondo applications before it's perfect but the results are well worth it.

_________________
LNLC Founding Member

FAKE FRIENDS: Never ask for food.
REAL FRIENDS: Is the reason you have no food.


Top
 Profile  
 
PostPosted: Thu Apr 03, 2008 11:15 pm 
Offline

Joined: Thu Apr 03, 2008 9:55 pm
Posts: 49
Location: flint michigan
where did you get the rings? ive been wanting to do this but dont have tools to cut perfect rings for a sub so i only make wood boxes i want to make a fiberglass one now


Top
 Profile  
 
PostPosted: Fri Apr 04, 2008 12:05 am 
Offline
King of Pompous
User avatar

Joined: Sat Aug 25, 2001 4:22 pm
Posts: 5596
Location: Ottawa ONT.
1. You can get a router and use a circle jig with it.

2. You can trace a circle and slowly/carefully cut the rings out with a jig saw.

3. You can buy the rings (usualy at a well inflated price) online or sometimes your local car audio store will cut them.


The cheapest way is to trace a line and use a saw. It won't be 100% perfect but you can get it close enough that with a few layers of fiberglass you'd never know the difference. For the inside of the ring cut it 1/32" smaller than the sub and use a drum sander on your drill to get it to the same size of the sub. If you have a router and circle jig just set the jig to the size you want and plunge the bit down. Go slowly with MDF or you'll burn out your router.

_________________
LNLC Founding Member

FAKE FRIENDS: Never ask for food.
REAL FRIENDS: Is the reason you have no food.


Top
 Profile  
 
PostPosted: Fri Apr 04, 2008 5:38 pm 
Offline

Joined: Fri Nov 09, 2007 5:46 pm
Posts: 1099
Location: Abbotsford, BC
is there a finished project pic ?

_________________
1995 Firefly 1.3 SOHC 8VALVE MANUAL
2000 Firefly 1.3 SOHC 16VALVE AUTO. Goals: full restoration, achieve stock MPG and HP or higher, finished look should be 'stealthy' and unassuming. Engine will need to be rebuilt later on to restore compression levels.


Top
 Profile  
 
PostPosted: Fri Apr 04, 2008 10:38 pm 
Offline
King of Pompous
User avatar

Joined: Sat Aug 25, 2001 4:22 pm
Posts: 5596
Location: Ottawa ONT.
Unfortunatly I only have one pic of it and its full of dust :P. The box came out after a summer when I changed cars and went to the scraper...

Image

_________________
LNLC Founding Member

FAKE FRIENDS: Never ask for food.
REAL FRIENDS: Is the reason you have no food.


Top
 Profile  
 
PostPosted: Fri Apr 04, 2008 10:40 pm 
Offline
King of Pompous
User avatar

Joined: Sat Aug 25, 2001 4:22 pm
Posts: 5596
Location: Ottawa ONT.
There is another FAQ with some fiberglass work that basicaly shows the same thing as in this one but its for a spare tire enclosure instead.

viewtopic.php?p=193469#193469

_________________
LNLC Founding Member

FAKE FRIENDS: Never ask for food.
REAL FRIENDS: Is the reason you have no food.


Top
 Profile  
 
PostPosted: Wed Mar 16, 2011 6:06 am 
Offline

Joined: Wed Mar 16, 2011 5:56 am
Posts: 1
Location: USA
m wrote:
Unfortunatly I only have one pic of it and its full of dust :P. The box came out after a summer when I changed cars and went to the scraper...

Image


That looks awesome! I've been wanting to do the same using fiberglass, that's an excellent idea, inspiring! 8)

_________________
http://www.respirated.com


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 14 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group