Carbon Fiber Spare tire well sub enclosure

[Hixson]

Well, after finishing the install on my SVT I realised 2 things; one a sub box with 2 cu. ft. and three 10's with large magnets is heavy. So is an amp rack built of MDF, aluminum, and plexiglass. So I decided to start over and lighten things up. My new plan is to scrap the box and go with a spare tire well enclosure made of CF. I was able to get enough at a next to nothing price so I want to try my hand at it.

Any one here ever worked with it? My plan was to make a mold of the well using expand a foam then remove the mold and vacuum bag the CF over it. I have searched this method on google and have a general idea of it but I am not sure what to use as a breather material to absorb the extra resin and what to use as a release material so it doesn't stick to the mold. Any ideas?

Second I am getting rid of the JL Slash amps (they are heavy) and replacing them with an Alpine PDX-5 until JL releases the 5 channel version of the new HD amps that Manville Smith of JL Audio has been hinting at. I will mount either amp behind the Audiophile sub woofer panel and make a light weight false floor out of 1/4" wood that I find is the lightest.

[megail]

i wouldn't make the jump from mdf to carbon fibre so fast. try fiberglass before you try carbon. its not near as expensive and you'll need to practice sanding and using the resin, otherwise it'll look like old man balls.

weight shouldn't be an issue.

[captain_jack]

I would also say that ur gonna need a very big oven as well as the vacum bagging. I would look for some light weight mdf and use fiberglass or you can use the carbon fiber instead of the fiberglass mat. you just wont get thereally nice carbo fiber appearence. are you trying to keep the three 10's? I would say do away with 2 of them and make a lightweight spec'd vented box. I too at one time had three 10's and thats what I did. Still have plenty off bass.

[megail]

oven? oven for what???? and what light weight mdf are you using??? i obviously missed this at the lumber yard.

[danager]

I would go with the fiberglass as well. This will weigh a lot less than all the mdf. With what you are talking about - making a mold, you would create a negative, and then have to cast a positive, then lay in your material. When the top of the enclosure is added, you will not see the material in the spare tire well.

[captain_jack]

Well from all the carbon fiber. The stuff I have seen built they bake it in a vacum bag setup. But I am also worried that you dont have enough vacum to form it correctly. And lightweight mdf is hard to find and a tad bit expensive but it available. They also make "bendy board" which is just flexable mdf. Its on page 20 of their online catalog. here is the link www.selectproducts.com

[RSkylineR34]

i have no idea how this would work out as a sub enclosure, but if you are of the adventurous type, i can offer some tips as i have done many CF layups (none for stereo euip.) .

try a sample part to familiarize yourself with the process so you dont waste all that carbon.

1. dont lay up on the foam. bondo and spray a high build primer, sanding it to the perfect shape. sand as smooth as possible (1500-2000grit). this will help in release and surface finish. put many coats of carnuba wax on the smooth primer.
2.next spray a light coat of a PVA mold release. clean your gun VERY WELL after shooting this stuff.
3. peel ply release fabric and breather material can be had from Aircraft spruce or similar companies. use one layer of peel ply, be rather generous with the breather. extras resin in the part makes it very brittle.
4. vacuum baggin is easy as long as you can seal well. also, you can get medical grade pumps off ebay for $40.
5. let the vacum pull for about six hours. then get some heat lamps near the part to cure the resin.
6. once the part has been released, let sit in mold to fully cure for about 24 hrs.
7 if you are mounting anything to the cf, like speakers, use aluminum bungs in the holes to act as washers. carbon fails quickly when crushed.

the whole process is obviously more complicated but these are some tidbits i can offer. also i have not proof read this, and take no responsiblity for anything. feel free to PM if you have detailed questions.

also do you happen to know what weave pattern you have? this could make a difference in the ease of lay-up. good luck

[Hixson]

The appearance doesn't really matter, the carbon fiber will be in the well. The baffle of the enclosure will be 3/4" MDF and the "frame" or square that sits atop the enclosure and below the MDF will be standard 2x4 cut to size. The CF will be molded to the frame. I'm staying with the 3 10's. I should have the 1.8XX cu ft that JL says to use if I can take advantage of every bit of space that is there. I don't like ported enclosures they really don't suit my taste in music. I have actually found quite a bit of info since I made the post. Vacuum bagging can be done rather cheaply and I have most of what is needed. I have a lab grade pump from eBay and polyethelyne will be used as my release (with holes) and bagging material. Cotton batting will be my breather. For a mold I will using 8 or 16lb urethane expanding material. I'm using plain weave CF it was cheaper than buying fiberglass. I have a friend that does engine work for an IRL team and was able to procure it for me.

[Ray]

if you're going with 2x4's and 3/4" MDF, your concern of weight of CF versus FG is a little confusing.

[Hixson]

The weight of the MDF box (41x 10.5 x 12, 3/4" and 1" MDF) versus the weight of the new enclosure is what I was referring too. Also the amp rack is heavier than I thought it might be. I constructed it with 1/2" MDF, 1/8" aluminum, 1/2" clear plexi and two amps, two fans, and some port work for cooling. I will weigh both when I remove them.

[spots25]

I would use fiberglass. If you want the cool look of CF, make a 'glass box and cover the visible parts with CF. Otherwise, the weight difference between a fiberglass box and CF box might be a pound. And any type of MDF has NO place in a lightweight stereo installation, if you want lightweight, use 1/2" baltic birch ply

[Hixson]

I got everything thing I need to start the enclosure Wed night or Thursday. People have been saying to use fiberglass, I have 5 pounds of plain weave carbon fiber that I got for a case of beer. If you can find a better deal then more props to you, I also talked with the guys at AVT Composites in Indy and they got me hooked up with everything I need to make this happen.

[rollin_loud]

sounds sweet i'm probably not the only one that wants to see pics of this when its completed!!

[Foci_Fosho]

you have 5 lbs of scrap C/F? or a 5 lbs roll of 52" x 48" or something? (nice price, btw)


Either way - Both will yield strong integrity, but one is better for show-case.
If it'll be hidden, not too much effort needs to be put in the sanding, and wet-sanding and polishing the extra coats of resin needed for that beautiful C/F glimmer.

[boostedzx3]

Make sure you post some pictures at least, I wanna see it.