Brahma + Fiberglass

m_harrison · 09-24-2002, 04:05 PM

I just bought my new car, and am planning on doing a nice fiberglass install in it. I'm going to shove a Brahma 15" in there powered by an Arc 1500D. The general concensus is that 1/4" of fiberglass is the equivalent of 3/4" of MDF. For a driver as potent as the Brahma, should I make the fiberglass thicker? 1/2" maybe? What about bracing? It is going into a wheel well, and will rest above it in a pseudo volcano type of shape.

NovaMan · 09-24-2002, 09:13 PM

Ill need to know the answer to this one too, as of im putting 2 12" brahma's in a fiberglass enclosure in a similer design (raised out baffle)

Rybaudio · 09-24-2002, 09:20 PM

Yes, I would reccomend doing at least 1/2" thick. Fiberglass is strong, but I think the 1/4" FG to 3/4" MDF is a little too generous of a ratio. And bracing as much as you can would help as well.

StaticX313 · 09-24-2002, 10:26 PM

ya I was hoping to grab a 15" brahma soon and wanted to fiberglass. What would you use to create a volcano type shape (such as what would u use to hold the fibercloth up while ur glassing?)? thanks!

RoB~

NovaMan · 09-24-2002, 10:48 PM

what i plan to do (im yet to 'glass anything but got the concept) is use fleece and just stretch and staple the fleece into the form i want then after soaking that down with resin lay a layer of cloth on top and soak that down and let dry. im pretty confident that my technique will work... if not ill be ticked lol

m_harrison · 09-24-2002, 10:57 PM

Quote:

Originally posted by StaticX313
ya I was hoping to grab a 15" brahma soon and wanted to fiberglass. What would you use to create a volcano type shape (such as what would u use to hold the fibercloth up while ur glassing?)? thanks!

RoB~

Well my plan is as follows. I'm going to make it in two sections, the bottom wheel well, and a seperate "volcano" piece which will attach to the bottom with resin and some more fiberglass. I am making the frame out of 1/2" mdf, with the baffle raised up about 8" or so. The baffle will be 3/4" mdf. I then plan on stretching some fleece (Or fg mat - I haven't decided yet) and then you know the rest.

Any idea's on bracing weird curves? I am assuming fiberglassing peices of MDF on the longer, flatter sections.

musthavemuzk · 09-25-2002, 11:35 PM

Quote:

Originally posted by NovaMan
what i plan to do (im yet to 'glass anything but got the concept) is use fleece and just stretch and staple the fleece into the form i want then after soaking that down with resin lay a layer of cloth on top and soak that down and let dry. im pretty confident that my technique will work... if not ill be ticked lol

well what Mac and I learned was that using staples sux.

so this time we used masking tape and pulled the wrap layer of glass cloth tight around the front of the kick and taped it on the back. as close to the middle as possible. but did not resin all the way to the center. then trimmed and sanded and filled.
the batches were mixed pretty hot so it did not take too long for it to cure.

do not worry about the uneven surface tht the speak mounts to as this can be fixed later. by doing this it gives you a better appearance as well as more even tension.

Monty

Steven Kephart · 09-26-2002, 12:25 AM

Quote:

Originally posted by musthavemuzk
well what Mac and I learned was that using staples sux.

so this time we used masking tape and pulled the wrap layer of glass cloth tight around the front of the kick and taped it on the back. as close to the middle as possible. but did not resin all the way to the center. then trimmed and sanded and filled.
the batches were mixed pretty hot so it did not take too long for it to cure.

We use hot glue to stretch our cloth with. Just be careful. The hot glue is well, hot. It can burn if you aren't careful.

Now as for fiberglass thickness, 1/2" is way overkill. Most boat hulls are made with 3/8" fiberglass. That should be more than thick enough for a sub enclosure. And you shouldn't need any reinforcement. A 1/4" would be a minimum, but still should be fine.

musthavemuzk · 09-26-2002, 12:37 AM

Quote:

Originally posted by a/d/s man
We use hot glue to stretch our cloth with. Just be careful. The hot glue is well, hot. It can burn if you aren't careful.

Now as for fiberglass thickness, 1/2" is way overkill. Most boat hulls are made with 3/8" fiberglass. That should be more than thick enough for a sub enclosure. And you shouldn't need any reinforcement. A 1/4" would be a minimum, but still should be fine.

hot glue to stretch the glass cloth?
or fleece cloth?

Monty

might have to be getting me one of them there hot glue guns

NovaMan · 09-26-2002, 02:19 AM

why wouldnt staples work very well... im talkin about stretchin the fleece tight for the first layer and stapling it down on the edges ever inch or so Go WAY overkill on staples but just to make sure everythin is good and secure before i start spreading resin and clothe.... why isnt this a good method just outa curiosity?