need advice on a fiberglass box - Third Generation F-Body Message Boards

mess21 · 11-14-2002, 11:06 AM

after seeing all the sucess out there with guys building there own fiberglass boxs i decided that i'm gonna try and build my own but the one question that i have is what kind of fiberglass should i use the woven mat kind or the choped up mat kind??? also i plan to make the top out of fiberglass also but how should i go about bonding the top to the box should i use screws hidden and from the inside or should i just use exopy and fiberglass matting on the outside and inside to bond the two together one more question i'm planing on puttin three 12's in the box the center one mounted backwards what would be the best way to divide up the air space in the box wood or just more fiberglass i've made plenty of very succesful boxes out of MDF but as u can probally guess this is my fist time tackling fiberglass thanx and HELP!!:hail: :hail:

This ad is not displayed to registered members.
Register your free account today and become a member on ThirdGen!

FyreLance · 11-14-2002, 11:56 AM

Here's some periods, looks like you ran out before you wrote the sentence.

............................................
............................................
............................................
............................................

That oughta hold you over for a while.

I would think it'd be easier to make the top out of MDF and the rest out of 'glass. That's what my friend does when he builds spare tire-well boxes. Works pretty well for him.

mess21 · 11-15-2002, 05:42 AM

anyone else have any input on this subject?

JPrevost · 11-15-2002, 07:03 AM

Use MDF for the speaker mounting ring. 3/4 works great and leave enough for the glass to bond to it. Then use the woven glass for the 1st layer. It's expensive but it's also the easiest to form. Once you've got a good start do the rest with the cheap stuff. Make the box at least 4 layers thick on the bends and at LEAST 6 layers on the large flat areas. You should be able to drop your box without it cracking (don't drop with sub in box

).
This is how I do it and it comes out perfect ever time.
If you're going to do the box pretty quick mix a little more hardener in, just a little more! This helps the box dry faster and so long as you work fast you can get it all done before the resin hardns up. Also mix a little resin and hardener at a time. The last couple layers use the proper mix ratio and let dry for a day at least.

mess21 · 11-15-2002, 12:22 PM

Quote:

Originally posted by JPrevost
Use MDF for the speaker mounting ring. 3/4 works great and leave enough for the glass to bond to it.

u mean i can make the top out of fiberglass but i whould just put like an inch or so of MDF around the holes for the speakers?

KicKeR · 11-15-2002, 02:30 PM

Yeah, although probablly would become difficult. I was gonna do that for my Barics, but I decided just to go with 3/4 " HDF and say f*ck it.

JPrevost · 11-15-2002, 08:06 PM

Quote:

Originally posted by mess21
u mean i can make the top out of fiberglass but i whould just put like an inch or so of MDF around the holes for the speakers?

You could do that but I was trying to imply that you cut out a complete ring (or square for the new solobarics) out of MDF and mount that into the fiberglass. This way you can position exactly where the sub will aim without having to suspend a huge heavy sub while the glass cures.

KicKeR · 11-15-2002, 08:40 PM

Yeah, thats a cool idea. Never really though of it that way I guess. That would make it quite a bit easier.

mess21 · 11-16-2002, 05:43 AM

Quote:

Originally posted by JPrevost
You could do that but I was trying to imply that you cut out a complete ring (or square for the new solobarics) out of MDF and mount that into the fiberglass. This way you can position exactly where the sub will aim without having to suspend a huge heavy sub while the glass cures.

thats exactally what i was plannin on doin great minds think alike:lala: :lala:

caleb · 03-18-2003, 01:16 AM

It is better to form the top out of MDF and just glass it into the box, rather than a top of glass, with MDF rings. If you are going to be pushing any kind of huge bass, the top will take a beating where the subs are mounted, and need as much bracing as possible!

FyreLance · 03-18-2003, 09:04 AM

Heh back from the dead

hramirez · 07-13-2009, 11:28 PM

i want to make a 12 inch sub box but i need to know what materials do i need to use

hramirez · 07-13-2009, 11:30 PM

i want to make a 12 inch sub box but i need to know what materials do i need to use reply to octavio198127@yahoo.com

UnSouled_RS · 07-27-2009, 11:04 AM

Read the posts up above, it lays it out pretty well. If you search the rest of the forum, there's a lot of great info here. Most people seem to use MDF with some fiberglass, and some type of carpet or vinyl (sp?) don't forget to seal your corners with caulking of some sort. Some people also put some cotton poly-fil stuff in to "trick" the sub into thinking it's has more volume. Hope this helps.