I am looking into some custom done boxes for my trunk. I want to have some fiberglass boxes made and be flush the wheel wells in the trunk, one on each side. I am using one 12" on each side done. They are going to charge me 300.00 per box, he is having the subs also be removeable. Is this is decent price for this work? Any ideas?

 

600 bucks for a f/g removable enclosure in each side panel. Pretty good, though i don't know that you want them to fire directly accross at each other, may run into some cancellation effects.

 

I would be worried about the materials and workmanship at that price. And how carefully they measure the box volumes. You can definitely build a box out of bondo for $300. But I wouldn't pay $50 for a bondo box.

 

What would be some ways to eliminate the cancellation effect?

What is the difference between a bondo box and a f/g?

 

you don't want a box made out of bondo. it'll be heavy.

 

Bondo is a universal fiberglass resin, marketed as an auto body material, frequently used in car stereo installs. It is a polyester resin with good weather resistance and not damaged by ultraviolet light. It is what most of the fiberglass work shone in the mags are created with. Most resins are similar in mass to water. Differences will mostly from additives. The weight savings in FG work comes from the design and incorporation of light weight cores. So the short answer to your question is that they can be the same, or different.

I currently use epoxy resin. A small amount lighter than bondo but magnitudes better bond strenth, hardness, stiffness. I can mix in fillers such as hollow glass microspheres at a 50/50 ratio or greater. The result is a resin much lighter and a greater volume of resin. This saves money and weight. There are many different fillers and they all have somewhat different characteristics. Some like fumed silica make the resin really thick so it would be impossible to wet out faric. The use of this is to make a putty like material similar to the bondo body filler that may be spread and shaped with a putty knife.

 

Well Maximus, I don't know about all that stuff like hollow glass microspheres, and fumed silica,,, and I have never used the bondo stuff either, although I do want to try that. But I'll tell you how I made my box. I live in south Louisiana, so fiberglass is one thing you find quite a bit around here due to all the hunting and fishing boat repairs.

I didn't want the strong smell of fiberglass in my car, so what I did, was I took some stiff but flexible "chicken wire" with the 1/2" square mesh and shaped it into the trunk where I wanted my box to sit. I used MDF on the sides where I could incorporate the thickness and strength, like on the front to mount the sub. Once I had a basic "wire and wood box" built, I pulled it out of the car and put it on a work bench. I then took a mixture of fiberglass resin and hardener (the same stuff used on boats), painted a coat onto the box, laid a layer of fiberglass cloth down and proceded to soak it with the resin/hardener mixture, making sure to extract ALL air bubbles. I let that layer dry, then I repeated this process about 3 to 4 times to make sure of thickness, strength, and solidity. I poured a total of about 1/2 gallon of the mixture inside the box to fill any cracks, spaces, and pockets on the inside. I did this in layers of course. I didn't put a whole 1/2 gal. at one time, although I guess you could. I mixed about 8-10 oz. at a time, and turned the box every which way to get everywhere covered.

After drying and sanding (alot of sanding), I covered the box with carpet, and what I ended up with is a solid and strong box with 4 to 5 layers of fiberglass strength on the outside, and 2 to 3 layers of coverage on the inside. The box holds my one JL Audio 10W3, and it sits on the passenger side wheel well in the trunk. I have full access to my trunk pass through, and love the results. Total weight of the box alone is 15lbs, and it sports .8 cubic feet of air space. I incorporated a 1/4" bolt into the fiberglassing so I can bolt it to the body panel to ensure stability. I now have a false floor built around it too, so it's not going anywhere. My box might not compare to the "professional"(hehehe) job you'd get from an install shop, but the money in my pocket tells me I made the right choice.

Not sure if this is what you wanted, or if it will help you at all, but GOOD LUCK!!!

DMAN

 

That is a good idea, thank you for your imput. I was wondering how I was going to avoid the terrible stink of the f/g. If I have any more questions about this project I will get back in touch with you.