Internal Bracing FG enclosures?
Printed From: the12volt.com
Forum Name: Fiberglass, Fabrication, and Interiors
Forum Discription: Fiberglass Kick Panels, Subwoofer Enclosures, Plexiglas, Fabrics, Materials, Finishes, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=25528
Printed Date: May 21, 2025 at 7:23 AM
Topic: Internal Bracing FG enclosures?
Posted By: tnrplaya
Subject: Internal Bracing FG enclosures?
Date Posted: January 29, 2004 at 9:52 PM
I am building a FG trunk enclosure, I am building it in two pieces; the bottom piece is a mold of the spare tire well and the top piece will be contoured. My question is how should i build the internal braces that keep the whole thing from exploding. I know that with a traditional MDF enclosure bracing is critical, and lack there of can be plain dangerous. I assume the same is true for fg. The problem I am running into is measuring the correct height and attaching internal bracing...anyone out there have any good ideas? thanks! If it matters, the enclosure is a sealed design and will house (2) JL Audio 12w6v2's powered by PG limited edition octane amp.
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PG Limited Edition Octane Aplifier
PG Ti400.2
(2) JL12w6v2
Focal 165KF
JL TR-690TXi
Sony XAV-7W
Sony 10 Disc MP3 Changer
X-box
APC 350W inverter
Monster 1/0
Irragi 180A Alternator
Replies:
Posted By: wht94stang
Date Posted: January 30, 2004 at 10:34 AM
What kind of brace are you looking for, the brace for the internal box for the spare tirewell? This is what i did for my spare tire well for my stang.  I don't know if your looking what to do to hold it togeather or what, clarify and i'll see what i can help ya out with.
Posted By: tnrplaya
Date Posted: January 30, 2004 at 12:27 PM
I am looking to find out how to make internal braces. I know how to get a secure attachment between both pieces, but I know that with a MDF box you have to build some supports inside "you should be able stand on your speaker box and jump up and down" ~JL audio website. but I am not sure how to do this with FG or if it is necisary (sp). my first thought is just to make some posts out of mdf and guess and check for the length but if someone has some better ideas, i am all ears!
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PG Limited Edition Octane Aplifier
PG Ti400.2
(2) JL12w6v2
Focal 165KF
JL TR-690TXi
Sony XAV-7W
Sony 10 Disc MP3 Changer
X-box
APC 350W inverter
Monster 1/0
Irragi 180A Alternator
Posted By: beyondamfm
Date Posted: January 30, 2004 at 12:33 PM
As long as your fg box is thick enough you should'nt really need any internal bracing, unless there will be more than two subs bigger than 18"s. but you should start with a frame made of MDF and then glass around that. ------------- The Clear Bra Guy
KCs premiere paint protection guru
Posted By: wht94stang
Date Posted: January 30, 2004 at 12:35 PM
ok when you have your baffle rings braced, i used some T shape metal posts. And i used a door hinge to hold them in the middle. Then took a nice piece of cloth, little thick, but stretchy. Once fiberglass'd my 180 pound body can stand on it after a good 4 to 5 layers. Is that waht you were lookign for? Hope this helps.
Posted By: tnrplaya
Date Posted: January 30, 2004 at 8:16 PM
I'm not too sure i understand the "t shaped posts" concept, do you have any pics? thanks. ------------- PG Limited Edition Octane Aplifier
PG Ti400.2
(2) JL12w6v2
Focal 165KF
JL TR-690TXi
Sony XAV-7W
Sony 10 Disc MP3 Changer
X-box
APC 350W inverter
Monster 1/0
Irragi 180A Alternator
Posted By: pureRF
Date Posted: February 01, 2004 at 11:58 AM
A good thing to use for amazing strength when making a fiberglass box is coremat. It can be found on any website that supplies fiberglass materials and is applied like mat.
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dream it, build it, fiberglass it
Posted By: tnrplaya
Date Posted: February 01, 2004 at 12:33 PM
so to clarify...bracing a FG enclouse is NOT necissary, as long as the sides (or parts mad out of glass are rigid enough? Currently I am 2 layers of bondo "cloth" and 4 layers of bondo "mat" thick....about .25'' is this thick enough or do i have to keep goin? thanks!
-------------
PG Limited Edition Octane Aplifier
PG Ti400.2
(2) JL12w6v2
Focal 165KF
JL TR-690TXi
Sony XAV-7W
Sony 10 Disc MP3 Changer
X-box
APC 350W inverter
Monster 1/0
Irragi 180A Alternator
Posted By: pureRF
Date Posted: February 01, 2004 at 2:54 PM
In fiberglass curves are extreamly strong without tons of glass but its mostly the flat areas u need to worry about. But no, it is not necessary to brace although it is done because people would rather brace and put less glass then not brace and put more. But if you layer the glass enough on the flat areas and have enough in the curves you will be fine. I would put on about 3 more layers on ur box in the flat areas and you should be fine.
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dream it, build it, fiberglass it
Posted By: tnrplaya
Date Posted: February 01, 2004 at 6:22 PM
Most of the FG is laid with a slight curve [look at the diagram] how many more layers should I expect to do? It will be a sealed enclosure for (2) JL 12w6v2's powered by Phoenix gold LE octane (approx 400w RMS) Thanks again everyone, you've all been super helpful! ------------- PG Limited Edition Octane Aplifier
PG Ti400.2
(2) JL12w6v2
Focal 165KF
JL TR-690TXi
Sony XAV-7W
Sony 10 Disc MP3 Changer
X-box
APC 350W inverter
Monster 1/0
Irragi 180A Alternator
Posted By: staudio
Date Posted: February 02, 2004 at 1:24 PM
If you've got flat areas that need reinforcment just use some string (heavy duty cloth strings, like cloths lines work well for me), soak them in resin, lay them on the internal area that is flat and fiberglass over them. This will add a slight but very ridged curve to a flat area allowing the outside to remain flat.
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