Custom fiberglass amp mount????

Systems Posts: 14,873
edited May 2003 in Custom Fabrication
Does anyone have any ideas on an amp mount for a JL Audio 250/1 in the trunk of my '98 Toyota Camry.

I guess I have somewhat of an idea but I have never fiberglassed before and was wondering what I could use to build my design in the trunk that will eventually work out to be my mold. Any kind of info would be appreciated on the whole fiberglassing process, such as the materials I need to make a mold and what kind of releasing agents can I use so the glass wont stick to the mold. Thanks in advance!!!
Post edited by Unknown User on


  • Jstas
    Jstas Posts: 14,718
    edited May 2003
    I am not quite sure what you are asking. I think you are trying to make a mold for the fiberglas?

    Anyway, what you might want to try is that expanding foam insulation from 3M. You can get it at any hardware/home improvement store. That is if you want to go with a free-form piece.

    For a sealer, you could use a water based polyurethane or some sort of finisher like that that is water based. Since it is water based, it shouldn't melt or deform the foam.

    To get teh shape you want, get a package of hack saw or coping saw blades and a pair of heavy leather gloves. Squirt the expanding foam out, onto a cheap piece of plywood or something. You don't want to get that stuff on anything, it sticks foever! When the foam stops and has been given ample time to set up and firm up, take a saw blade, put on your leather gloves and start carving the foam until you get the shape you want. Cover the shape in the sealer. Just use enough so that the surface is smooth. It may require a few coats because teh foam is going to suck some of it up. When it dries completely (may have to sit overnight), you can start laying fiber glas.

    For teh fiberglas, you are going to probably want to mix a seperate batch of resin for each layer of cloth because it has to cure in between. If the resin on the mold is curing then you can be damn sure that the rest of your resin in your bucket is curing. So don't waste money and time. Take your time and do it right.

    Do as many layers as you feel comfortable with. The thicked the final product is, the stronger it will be. Make sure you let the resin cure to at the very least a slight tackyness, in between application of layers. Slight tackyness being that your finger sticks to it but when you pull it away, your finger is clean and doesn't feel sticky. Also remember though that eventhough thicker is stronger, it is also heavier and less flexible. That may cause issue for you during installation.

    As far as the foam mold goes, foam will invariably stick to the fiberglas. However, using foam has a purpose. It was easy to carve up and it will be easy to seperate from your formed fiberglas. If any is stuck to the fiberglas, a utility knife or razor blades can be used to seperate the foam from the fiberglas. Any foam that is stuck in the fiber glas can be sanded off either by hand or with a power sander. Just be care not to remove too much fiberglas. The foam will come off extremely easy. The real purpose of teh sealer is to make sure that the foam maintains it s shape and provides support for teh form. Once teh first couple layers are put down, the fiberglas will hold its form by itself but it will need support and that is what the foam is for.

    Take your time, use your head and have fun! Do it outside too cause fiberglas resin will make you woozie and can kill you. Also, I hope I do not have to stress using care when using sharp knives and blades and such? You may want to use safter goggles when carving or removing foam. It tends to fly everywhere and if it gets in your eyes, that can be bad.

    If you are planning to mount an amplifier to the fiberglas, you may want to embed a piece of MDF in the fiberglas for a surface to mount the amp. Fiberglas can crack when you crank down on it with a screw. You can use straight fiberglas but, I would highly recommend drilling mounting holes and using bolts with washer and rubber washers to go up against teh fiber glas. It will keep the strees off of teh fiberglas and keep it from cracking. The rubber washers should go between teh metal washers and the fiberglas to keep them from binding and squeaking. The binding can also cause the fiberglas to crack and that would be bad.

    If you want to paint the fiberglas, rough up the surface you want to paint with sand paper. Use a primer for a marine application that is designed for fiberglas so that it sticks and stays stuck. Lay the primer on in a couple of coats. 2 or 3 wuld be good. Then you will have a great surface for painting your color coats down. If you will have a wavy shape and use a light color, use a dark primer, it will help set off the curves by adding depth to the paint. If you use a dark paint, don't worry about the color of the primer. You may want to get it professionally painted. Its up to you.

    Remember that you are creating something here so use your imagination and ingenuity! It's a chance to make something from raw materials with your own two hands! Don't be afraid to try something that you think might work. If it doesn't, well, learn from that mistake and move on. Don't get discouraged if your first try doesn't come out so well. Try it again and you wil defintly get better results. Good luck with it!
    Expert Moron Extraordinaire

    You're just jealous 'cause the voices don't talk to you!
  • George Grand
    George Grand Posts: 12,258
    edited May 2003
    Fireball John,

    This has nothing to do with Polk. I've been on the road for some time, and WILL be for another 3 weeks. Theresa told me I have an e-mail from you. Sorry I haven't been able to answer it friend, but we'll pick up where we left off when I return to the U.S.

    I did start up another e-mail account for this trip. I'm at:

    If it's important, write. If not, I don't get to use a computer too often so wait till I get back.


  • PoweredByDodge
    PoweredByDodge Posts: 4,185
    edited May 2003
    "fireball john" -- heh heh heh... imma start callin' you that from now on. :p
    The Artist formerly known as PoweredByDodge