After you guys make the wood frame for whatever you are building what do you do? Do you cover it with fleece and resin and thats it? Or do you proceed to put layers of fiberglass on top of that? I read that the best thickness is to have three layers of 3 oz mat for your project. And then to use the thumb nail test. I was just wondering what you guys did to your projects or what you thought.

 

Most people will disagree with me here. Most will fleece and resin and then layup the fiberglass matt from here. The correct way though is to cover the frame with either cloth or knytex and try to get it as smooth and flat as possible and resin this. Then, on the inside, layup cut or chopped mat and more resin. For most uses go for about 6 layers and it should be plenty strong. Then on the outside you would use something like rage gold to smooth, then some layup primer and either paint or cover.

 

www.the12volt.com

 

Back when I used to do full systems, I would build the frame with wood, and then wrap it in fleece. I would then load in the resin, then bondo, sand, and so on...depending on if the box/fiberglass part was to be painted, I would make it smoother. If I was going to wrap it in fabric, it did not need to be very smooth.

I would use fiberglass for small corners, or air holes to get some strength there.

 

depends on the application... at first i will start to agree with BSP07tc... but i usually use grill cloth... especially if the box is getting painted... its really smooth when it dries with resin.... then go to the inside with your matting cause it will save time sanding... then a nice coat of lightweight body filler (evercoat, rage gold... usually its what ever my guy gets me) now if its getting wraped... one to 3 coats and a good sanding it all it takes... painting...usually i go 3 to 5 layers of body filler a nice coating of metal glaze and then a thick layer of filler primer... then all the body shop has to do is block sand and paint it...

also... depending on the subwoofer your going to use varies your thickness... example... a JL W7 or rockford T1 will get like 8-12 layers of matting just so that its strong enough to handle the pressure... where as like a alpine Type S or something of that nature will get 4-6 layers... hopefully i helped a little...

 

im building my fiberglass tunk and amp rack right now. what i did was make sure you soak the fleece verrrry well. that will make it very strong. then i put a layer of mat on the outside, making sure to put it on smooth and even, it will save with sanding. then id cut the circle out for the sub, and on the inside layer ther fleece with more resin. once that cures then i add more chop mat inside. it is much easier to re enforce it from underneith because you dont have to worry about keeping it smooth and even.

as for how thick you should make it. take you thumb and press around hard all over the box, if you get to a part that flexes, you know you need to add more layer in that spot.

 

Sweet awesome job explaining it all guys. Im planning on having two JL W6 cause i work with car audio. I sure its gotta be a pain in the butt to place chop mat inside the frame. I sell car audio and I am starting on making boxes so I just wanted to know what you guys did. And also do you have any hints on flush mounting the subs?

 

to flush mount the subs, you can make like a mdf ring that the speaker will sit on and screw into. then you can cut a bigger mdf ring thats the size of the out side of the speaker. glue em both together with some woodglue or liquid nails or something. ive found it easier to route out the edge of the mdf ring to attach the fleace, it provieds a good lip to soak in resin with out being a big lump.

 

Hmm so i could basically trace out the circle of the sub that the box came in and cut out the inside of that... then get a compass or something and measure and extend about two inches. Make another circle with the outside diameter the same as the other but make the inside diameter one inch smaller.... uhhh ya

 

lol yeah that works. and on that out side circle, route the edge, that way it gives you a little lower lip to attach the fleace too. that way when you resin and add layers of fiberglass, it makes it flat and flows together nicely. hard to explain lol

 

sweet... now i just gotta figure out how to place chop mat inside the damn box. do you guys wait till the fleece dries then dremel out the circle for the sub and kinda shove your hand in there to put the chop mat in place?

 

wait for it to dry. what i do if the inside surface is large ill cut a large part of the back of the box out so you can get easy access to the inside. then all you have to do when your done in put the peice you cut out, back into the hole and glass a few sheets over it to make it nice and strong again

 

I'll agree with bsp07 and harmonic and just add:
- fleece is great for simple curves and building thickness quickly.
- but speaker/jersey cloth is better for doing small or complex wraps.

Also, even if youre doing something like an amp rack where vibrations dont matter make sure you make your frame strong enough that the glass doesnt warp it when curing and it doesnt crack from the torsion it might experience when bolted to the car.

 

I agree with the try and do it all from the inside. I did everything on the outside. This was my first time ever dealing with fiberglass and it was impossible for me to get the glass smooth as you can see in my pictures below. I have been bondoing and sanding and cant get this box smooth. I have considered trashing it and starting from scratch and leaving the back off so I can do everything from the inside.

If you check the different pages it shows from the purchase of subs to the purchase of tools and the entire build. I need to update.

http://forums.scionzone.com/smf/index.php?topic=1931.30

 

very cool stuff here... now its time for me to work. maybe incorporate some neons in the MDF and some plexi too... so much to think about.

 

Oh and what kind of filler do you guys use... I know there is more out there then just bondo lol. But do you use the rage gold first or a polyester filler? I ask cause I like painted boxes and wanna get the smoothest possible finish.

 

for thicker filling, i like to use bondoglass or duraglass, its like bondo mixed with fiberglass strands, its stronger and less likely to crack. its good for things thicker than say like 1/4 of an inch. you dont want to apply bondo too thick, or it will crack. so fill and mold with the bondo glass, then do a layer of bondo or rage gold after that. rage gold is a better body filler than bondo i think. sand it down and you should be almost perfectally smooth. if you still have some pin holes or small tiny areas you need to fill in, use a spot/glazing putty. alpply that on in thin thin coats and use a good spreader so it will fill in any tiny spots.

 

i think this has been the most informative thread i have ever been a part of. Thankyou so much guys for all your help and I am def. gonna do some crazy setups in this car. But first I think I will practice on my girls Celica lol.

 

Have fun with it. Fiberglass is very tedious and aggravating. If you dont mix it perfect you will either wait forever for it to dry, or loose alot to it gelling up. My project is coming along. I did the amp rack today, well started it.

 

lol i want to stress this: make as you streatch the fleace aaround the subs, it has an even slop and curv on both sides. or youll spend forever correctin this (like i am right now)